A better Best to Worst mods list.
 

I came here hoping to further improve MPG on a 1997 Mercury Tracer Wagon. So I clicked the sticky for the list of best to worst recommendations. It is often inaccurate with much conjecture, and a lot of posts show a lack of understanding about exactly how a car works. Also with some things that are listed, the mpg you will save, will be off set by the extra amount of strain you are putting on your cars different systems.The other problem I had is the stickies on most good boards are organized, contain few posts, and aren't filled with in-theory-I-hope-and-pray-this-works type posts. I would suggest a moderator edit it accordingly.


I am not going to bother with things that might give you .0001 and claim that every little bit helps when its a waste of time/money. This is grounded in real world advice. I will start out with easy things and thigns that you can simply switch to when the current component wears out and move to more difficult, costly, but still effective things to do.

This sticky was good info:
https://www.gassavers.org/showthread.php?t=1088

This sticky was bad info:
https://www.gassavers.org/showthread.php?t=2584

To begin:
When thinking of how do increase mpg remember that, gas used is determined by load and RPM. Decreasing load and decreasing RPM are how you will improve mileage.

1) Drive less aggressively, and just plain drive less. Keep RPMs down when accelerating, acceleration is where most of your gas is used. If you maintain a constant speed and accelerate tot hat speed at a slower rate your mpg will improve in a direct proportion to how much your driving style improves.

2) Maintain your car. Worn out 02 sensors (BIG ONE HERE), plugs, dirty trans fluid, dirty oil, etc are all bad for mpg. That rough idle and miss from a bad IAC and torn plug boots aren't helping either. Check and clear codes as they can affect this as well.

3) Buy a car that gets decent mpg. Guess what? Your Chrysler 300C SRT-8 isn't ever gonna get 30mpg around town. Or 20. Buy something that will.

4)Minimize engine accessory use. There are mods to help with this as covered later, but most people underestimate the amount of engine load that goes into turning your A/C, alternator, water pump, and power steering pump. Again I will cover modifications to reduce or eliminate the use of these items later.

5)Weight reduction, take out that spare tire, back seat, passenger seat, rear speakers, stereo system, and anything else that you can. Buying a car with manual items like manual door locks and crank windows will help with this as well. Serious mods to improve this are covered later. Often replacing you chrome wheels (either stock or otherwise) with 15" (or 16" if you have large brakes, and don't wnatt o grind the calipers) OEM/Aftermarket alloys can work wonders for this.

6) Run the lightest weight synthetic oil you can get away with. Change over to a synthetic oil (Not fake synthetic, real synthetic, like amsoil or royal purple. A PAO synthetic) in both your engine and trans. This will improve parts life, acceleration, everything. Running 5W20 engine oil will net you a noticeable mpg increase over say 5w30 or 5W40. Although if your car burns oil you should run the lightest weight you can to prevent it from burning oil.

7) Keep tires inflated, this could even be moved up as it is very important. Over inflating can be dangerous and cause poor tread wear, but I do it on the rear tires of FWD cars. Keep the front of FWD and all of RWD at the correct spec as stated on the sidewall.

8) Run harder or low rolling resistance tires. This is an easy thing to do, however how well it works is questionable. There are conflicting opinions that you can judge for yourself and your situation. There are some safety concerns with this, reading up on them and weighting the cost and benefits of your decisions are the best way to make a logical choice. Some Info: https://www.tirerack.com/tires/tirete....jsp?techid=29

9) (Automatic transmissions) Shift into neutral and rolling up to stop lights. CAUTION: Shifting into neutral at high speeds (and low speeds) for any distance can be very bad as in automatic transmissions a drum inside will no longer receive lubrication and can explode causing VERY costly and time consuming repairs. Although it is fine at like 10-15 mph for a few feet, or while at a stop light. Do NOT do this at a substantial speed. I know this from drag racing experience where people have blown up their transmissions by shifting into neutral after a pass.

10) Air dam blocking, I do not know much about this, obviously it is made to improve aerodynamics and therefore engine load. This can have some horrible effects, especially for your transmission. If you are going to do this you NEED to add a transmission cooler. A transmission cooler is a good idea anyway as it adds more fluid to the system, (and therefore more heat absorbing capacity) and will GREATLY increase transmission life in cars that do not have them from the factory. Obviously also if your cooling system isn't up to snuff this can cause decreased reliability, overheating engine knock leading to blown head gaskets, new engines, and new transmissions. I would strongly consider the potential costs that you could incur as a result of this mod for making a logical decision. However a hotter car will get better gas milage while it runs.

11) Drafting. No explanation needed here, but maybe your life isn't worth the extra 2-3 mpg? Again cost and benefits, if you are a bastard with no children and the world doesn't need you, draft all the semis you want.

12) Gas mileage indicator, some cars come with them now, adding one helps add consciousness, as well as lets you see what brands of gasoline work best with your car and how well your mods are working. For sure one of the better mods out there.

13) Change to a hotter thermostat. Only do this if your cooling system is up to snuff and properly maintained. Switching form the stock (usually to 170-180) costs little, is easy on most cars, and can net some real world increases. Of course detonation can occur if it gets too hot which will lead to shortened engine life or engine failure.

14) You can add on taller tires to drop cruising RPM.

The following are a little more advanced and require your own research into the cost and benefits. Generally if you cannot perform your own labor, they will not be worth it.

15) BIG ONE HERE. A simple mail order tune and SCT XCal 2 (or whatever is out there for your vehicle) can often net a few mpg (depending on how "on the edge" you're willing to go) This can work well in conjunction with many of the below listed mods. If you have an OBD-II ford vehicle, the Xcal/Xcal2 can be a simply reasonably priced way to have significant long term benefits. There is even a company out there using it to offer a plug and play switch to E85 if its available in your area. The xcal2 has data logging, as well as use in tuning and is a OBD-II code reader.

16) Getting under drive pulleys for your accessories will decrease engine load, although it will adversely affect things like your water pump efficiency and alternator charging ability, this shouldn't really be a problem as long as your cooling system is at factory specs and you don't have a 10 billion watt stereo system. To get maximum fuel economy, Delete AC (Lots of weight removed as well as not using it freeing up engine load), if your car has a version with a manual steering rack or its offered in the aftermarket, delete power steering. Install an electric water pump such as one from Meziere, and run an underdrive pulley on your alternator. This will net a noticeable mpg gain as well as power gain. Lets also not forget those of you who still have a smog pump thats belt driven. Most people here have FWD cars but if you have a RWD car that has a clutched fan for god sakes switch to electric. A Lincoln Mark VIII fan(best) or Ford Taurus fan(still very good) will provide better cooling that many aftermarket fans. Get one from a junk yard.

17) If you have a RWD car, change the rear gear ratio for your type of driving. If you only drive in the city and have a heavy car with 3.08 gears, you can greatly up your mpg (and transmission life) by switching to a more city friendly gear in the range of 3.55s or 3.73s. This will also greatly help acceleration of course. Conversely if you drive mostly on the highway and have 3.27s or 3.55s in your car switching to 3.08s (using ford 8.8 gears in this example) or 2.73s will drop cruising RPM.

18) If you have a car that asks for high octane gas or want to run a ragged on the edge type tune, a methanol kit can be built in your garage easily for less than $200 installed. You can run isopropal alky, washer fluid, straight meth, or straight water, either way this will increase octane, decrease detonation, and allow you to lean out your gas use and A/F even more in the upper RPMs. Great for sue in conjunction with a dyno tune.

19) Weight reduction that requires commitment. This goes beyond removing seats and spare tires that you don't need. Take out everything, make a sheet metal dash, A/C, heater core, smaller battery, aluminum radiator, remove all sound deadening, switch to super light weight aluminum wheels, there is a long list. Aluminum heads, aluminum blocks, etc. Heres just a short list with some expected gains.: https://www.theturboforums.com/smf/in...?topic=21593.0

20) Weight reduction/aerodynamic body kits. The only time this is worth it is if you car has body damage that needs to be replaced anyway. Having said that replacing steel components with fiber glass, and you glass side windows with lexan can shave off some extra weight.. You can get full fiberglass front ends from places like harryglass and others. For aerodynamic body kits, many if not most of them are actually worse for aerodynamics. Weigh the cost and benefits for your situation carefully here. This is more race car stuff, if youre trying to have a fast car that also achieves good mpg,

21) Got boost? Turbocharging and supercharging will allot you a significant increase in gas mileage. I have seen up to 8mpg increases when properly tuned. I myself had a supercharger on my 1998 Mark VIII and picked up 2mpg on AVERAGE and that was with a heavier foot in a 4000+lb full weight car. We're talking 150mph+ highway blasts and drag racing factored in.

22) Simple cold air intake and higher flowing exhaust. Make your engines job easier and you will net a small mileage increase and HP increase.

23) Engine/Transmission swaps. Obviously a more fuel efficient engine or one that isn't a worn out piece of crap, will get you better mpg. A manual transmission not only offers you more control but also reduces drivetrain losses.

Some concerns from the other sticky: (I.E. **** that is just plain bad advice)
1) Spoilers as an aerodynamic mod.....this ADDS weight and ADDS drag. REMOVE spoilers to increase MPG not add them....duh...
2) Solar cells for your battery, this will not decrease alternator load by any reasonable amount and is generally a retarded idea. The costs GREATLY outweighs the savings if there are any at all because of the weight you added and the cost of this mod. Genuinely horrible idea.
3) Get rid of your alternator completely and charge your battery. Horrible idea again. Not going to explain it, wouldn't work, blah blah blah.
4) Limit power use. Obviously not thought this one out . First, you overestimate the alternator load this causes. Enjoy your radio. The cooler air form driving at night will likely net you better mpg that the load caused by using your headlights... seriously think this out.
5) Golf Ball Style Dimples........wtf?
6) Free All Toll Roads.....I don't know where you're from, but most toll roads have electronic mechanisms so that you don't have to stop and it gets taken from your account. Further more freeing all toll roads would decrease the incentive not to take the toll roads and would cause congestion. Think this out.
7) Closing Windows....Yes if you can, however its better to have them open than to use the A/C.

Comments, suggestions, questions are welcome.

Well, first
 

Well first, welcome to the site...

Second, have you searched each of these ideas for experiments or further discussion?

Not necessarily. An engine is most efficient at load. If you're referring to electrical load, then that's different.

Any proof of it being more dangerous?

I'm afraid most of these are over-generalizations -- especially for a first post.

-RH77

Considering I've been coasting in neutral with the engine on and off if I'll be coasting for more than about 30 seconds for the last 20k miles from speeds ranging from 10 to 70 mph, I think that I can safely say that the transmission will not explode. The bearing is still lubricated when the engine is on, so coasting in neutral with the engine on is no issue at all. When it's off, it isn't receiving lubrication, but I don't believe that it will lose its lube and cause damage in the 30-60 seconds that it's spinning before the car comes to a stop.

All in all, I think you restated most things well, but your hostility towards certain ideas makes me skeptical of your overall thought process.

I personally like the logic of the previous thread over this one. Your facts seem a bit skewed at some points.


Maybe not, but my sub 2 ton car can certainly get 25MPG doing my daily driving. When calculating what it would cost me to get a car with better gas-mileage, going from 25 to 40 would save me 400 dollars A YEAR in gas, that is driving 840 miles a month. 400 a year is certainly not enough to buy a different car as I would probably spend double that getting it up to snuff in repairs. Maybe for other people a different car would make more sense but doesn't work out for me.

The consensus I have found is that electric windows are lighter than manual, I cannot find a definitive source on this but it makes sense in my mind.

I hadn't heard about the transmission being cooled as a big deal, will have to look into that.

How about everyone can do what they want inside the law and decide for themselves if they want to draft? I didn't realize I was asking you for permission to draft. I like that you are presenting drafting as possibly dangerous.


Definitely a good thing to do, I just wish I could find a cheap one to hook up to my car that doesn't have obd. I would need something to read my mileage and something to read my fuel flow and put two and two together for me. My car doesn't have any computers micro managing it :).

How long will an electric water pump last? 5 years? Might not be anywhere near cost effective, have you done calculations on that to make sure it isn't a .0001% mileage gain after calculating what you spend on a pump?


Have you read through many of the experiments completed here on the GS forums? Granted a solar panel doesn't create much but if you only drive your car every few days and leave it in the sun the rest of the time it can add up. Especially if said car is a 3 cylinder metro.

If you think getting rid of an alternator is a bad idea then please explain it, a member here runs his car without an alternator and uses batteries he charges at home to provide his electric needs. Did you read about his experience with this technique?

Would you disagree that having your windows closed improves gas-mileage? If it helps it is nice to know, maybe some people are like me and can open up a vent inside the car in lieu of opening a window and didn't know before that it would be better for fuel economy with the vent.


Instead of making a whole different thread bashing the previous maybe we should continue to collaborate on our ideas and experiences and grow the other list. Just my opinion.

Fourthbean

I honestly haven't read either sticky. Regardless, I'll attempt to confine my thoughts to what I actually know.
That is a falacy for one important reason:

1) Injectors that are oversized to support higher horsepower are poor at low pulse width operation. With very short pulse widths, they may not open fully, or may open irregularly. Additionally, variances between the injector flow rates are magnified at low pulse widths. This results in uneven fueling across the cylinders with a variance between each combustion cycle.

Because the oxygen sensor only sees the average of this condition, the computer makes it's adjustments based upon that average. Nevermind that one cylinder may be consistantly running slightly rich and wasting fuel while another is running more lean - both of which result in lower economy at low engine loads.

At moderate loading, the injectors are working more within their specified operation range and can more accurately meter the fuel individually, and the variance between the flow rates of each injector is minimized.



I'll just say never say 'never'. Aerodynamic enhancements can count for allot on a highway driven vehicle.




That's a bit of an absolutist position isn't it? One need not be 3 feet off the rear of a semi trailer to reap the benefit of a draft. I've frequently found benefit at distances well in excess of what other dimwits will dart into and follow at. Even 50' off the rear of a full height semi trailer offers a draft benefit that is relatively safe - particularly when you consider the typical superior stopping distances of passenger vehicles. (But I do drive a 4wd pickup which will presumeably clear any hazards within the lane that the semi does.)



I agree that the majority of spoilers on most cars are simply decorative fluff, but even minor changes to how air seperates from the rear of the car can make a measurable impact on FE. I'd be reluctant to add one on the hope that FE could be improved with it, but already having one leaves one the option of testing for a change without drilling any new holes.

I wouldn't do it myself, but people are doing it with success. What that means to FE however is open to scrutiny.


That said, you are entitled to your opinion. What many people here are trying to do is find effective means to improve the FE of the vehicles they drive because the manufacturers were too cheap or nervous to implement.

Not everybody's driving conditions are the same either. While one person might kill a battery on their long commute by disengaging the alternator, another person who only commutes 5 miles to work could do this indefinately with recharges at home. Likewise, many people drive what works for them and must work within the restrictions of that. Sorry, but as much as I'd like to be able to, a Prius isn't going to tow my 5000 lb boat and trailer (very far anyway). But a 1 mpg improvement on the FE of my truck for daily use is worth attempting to achieve. (At $4/gallon and a 30 gal fill, that's worth $9 or an extra 30 miles per tank.)

I think there's a pretty big difference between the heat/stickyness of the band/s when shifting into N after a ~100mph quarter mile run, and at ~45-65mph/~2k rpm. Yes, shifting into N after a quarter mile run may be a bad idea, but doing so during a sedate drive? Not so much imo. ;)

i think you guys forgot the different between a spoiler and a wing. huge difference.

also it is definitely better to drive @ 65 with your windows up and a/c on newer cars. a/c systems are more efficient than they used to be. before anyone hears your rebuttal, note how i quantified that.i agree

yes but you drive a car that has been getting 20mpg and the difference saved between getting a car that gets 40mpg will be closer to a savings of over $650 a year. 40mpg cars are not too hard to come across for less than $2500. also gas will not be costing less than $3 for much longer. its not even available here for less than $2.70
i would love to see the statistics on that, but before that, i would love to see how it could make sense in your mind.

Although some spoilers certainly do add drag, some seem to decrease it. The 2002-2003 Saturn SC2 has a much more prominent spoiler than the SC1, yet the SC2 has a Cd of 0.31 compared to the SC1 that has 0.33:

Eh, they probably live in 95% of the USA that still has manual toll road paying.

Besides, the "fast pass" are optional in every instance I've seen them, making manual payment still mandatory for most drivers.

As mentioned by previous posters, cutting down the smugness would help a lot. Constantly telling people to "think this out" only makes you look like you're looking down on everyone else.

Accelerating:
Ironically enough, flogging mine gets the best mileage when accelerating. Gasoline engines are load bearing beasts; more efficient when working within their specific load ranges.

Buy a car that gets decent mpg. A SRT-8 isn't going to cut it
Eh anything is possible. I'd like to submit my rolling brick as an example.

4)Minimize engine accessory use.
This could vary greatly depending on your engine and accessory setup. For my 4.0 the only thing that consumes extra gas is my A/C compressor. The alternator and PS under full usage doesn't phase it.

Run the lightest weight synthetic oil you can get away with.

Varies again on engine, running too light or too slippery of an oil can cause excessive wear on internals. Mobile1 is known via oil analysis to consume 4.0 blocks due to its inability to adhere to parts.

(Automatic transmissions)
Dropping into N from 75+mph has yet to blow up any of my familys autos....So long as the input shaft is spinning usually the oil pump is also going.

Most automatic equipped cars have a tranny cooler built into the radiator or have an external cooler located elsewhere (01 Town and Country). Unless your cooling fan has been knocked offline somehow and your cooling system as a whole has been heating up, your tranny isn't going to die anytime soon. If you tow, then death is a possibility.

Drafting.

One doesn't have to ride on the trucker's rear end, anywhere from 2-3 seconds behind will usually net benefits. Or if you have a CB let the driver know you are there and what you are doing so that during an emergency s/he is aware of your existence.


E-Fan
I did that, noticed no change in MPG, little peppier down low but thats about it.

Regearing

Rear gearing is quite expensive, going from $500-$1000 a diff. Going as far as 3.73 to 3.07s or even 2.73s will make for one gutless ride. Going from 3.07s to 3.73s will up your acceleration but I doubt much of a MPG change.

How will regearing save your tranny? I can see saving the clutch, maybe.


Weight reduction that requires commitment
Lots of $$$$. Viable yes, but not very practical IMO. Works for a track rig or a buggy but on the road? Probably a bad idea. And a new aluminum block runs for quite the pretty penny.

1) Spoilers as an aerodynamic mod.....this ADDS weight and ADDS drag. REMOVE spoilers to increase MPG not add them....duh...

If your aero is crap, it could help

2) Solar cells for your battery, this will not decrease alternator load by any reasonable amount and is generally a retarded idea. The costs GREATLY outweighs the savings if there are any at all because of the weight you added and the cost of this mod. Genuinely horrible idea.

Solar cells aren't that heavy. Plus when you are at work/school whats your rig doing anyway? Sitting out in the open under the sun, might as well peak out the battery so the alternator doesn't have to.

3) Get rid of your alternator completely and charge your battery. Horrible idea again. Not going to explain it, wouldn't work, blah blah blah.

Parents had a '76 Cadillac DeVille with a fried alternator and a 5.0l big block, the thing was good for about 2-3 20 mile trips before the battery would finally crap out.

For toll roads why do I want to spend an extra $20 bucks a month? Thats about half a tank or so right now.


Welcome to GS! :D

This is just too funny.

"I'm new to your group, and it's a piece of junk"

You have all been very sweet to him. What a great place.

OK

This makes sense till you think about it. Gas use is determined exactly as above. *Useful Work* is not. E.g. an engine idling at 2200rpm uses less gas than an engine at half-throttle at 2200rpm. However, the engine idling has 0% efficiency, wasting all the gas that goes in, whereas the engine on half-throttle at 2200rpm is running at up to 40% efficiency :) So, more is less in this case :D

[QUOTE=Spinningmarkviii;50303]1) Drive less aggressively, and just plain drive less. Keep RPMs down when accelerating, acceleration is where most of your gas is used. If you maintain a constant speed and accelerate tot hat speed at a slower rate your mpg will improve in a direct proportion to how much your driving style improves.{/QUOTE]

See above. Faster acceleration is more efficient than slower accleration, if done correctly.




[QUOTE=Spinningmarkviii;50303]3) Buy a car that gets decent mpg. Guess what? Your Chrysler 300C SRT-8 isn't ever gonna get 30mpg around town. Or 20. Buy something that will.{/QUOTE]

Most members here get 70-130% of the EPA, even in town. So, unless that Chrysler has less than 16mpg about town (EPA), then it will be getting 30 or more mpg around town.

A cars cooling system is designed for the hottest, most humid day, with the owner thrashing the car. So, if you are sympathetic to the car, and drive more gently, you can use a block. I have a partial front undertray, and 100% grille block, and my car doesn't overheat. I do get about 130% of the Town EPA mileage around town, however.

[QUOTE=Spinningmarkviii;50303]11) Drafting. No explanation needed here, but maybe your life isn't worth the extra 2-3 mpg? Again cost and benefits, if you are a bastard with no children and the world doesn't need you, draft all the semis you want.{/QUOTE]

I get 7-8mpg more drafting; I guess the faster the semi goes, the more gains you can get, but also the more dangerous it is. Here in the UK 'semis' go at 56mph by law (all electronically limited to 53mph in reality). Real 'hardocore' fuel savers do D-FAS (drafting with the engine off). This is seriously cool and everyone should do it :D :D :D

Kamm shaped spoilers decrease aerodynamic drag. Also, the little spoilers you find on most euro cars these days also decrease drag by promoting clean seperation of the air stream.

Actually, this idea kicks a$$!. You could easily get 50W of solar cells, and, if you increase the efficiency of the electronics in the car (e.g. bulbs, more efficienct fuel pump), a significant amount of the energy will come from the sun (directly), rather than from the sun (indirectly from gas).

The second good point is this keeps the battery topped up (especially when engine-off-coasting), meaning less drag on the alternator when driving about.

The cooler air at night will - increase aerodynamic drag, increase 'pumping losses' from the engine (assuming you are maintaing a constant speed), and slightly worsen fuel vapourisation. The headlights, on the other hand (together with tail lights), will probably take about 300W (or about 0.5 BHP) from your engine, constantly.

THis would work but I'm sure no-one could actually do it!

-------------------------------------------

Another controversial idea would be...

'Weight reduction is not always good. If you do a lot of driving in hilly country, with low traffic levels, slightly more weight will mean you can put more energy into your car, with the engine at the most efficient power setting, and then coast for longer with the engine off'. I did severe weight reduction (rear tyre, carpets, all seats except drivers, all plastic from boot etc). My best economy has actually happened since I put all the stuff back!

I don't think your group is a piece of junk, just that sticky is a piece of junk. The other one is great. Also I said weight the cost and benefits to make a logical solution for your situation several times throughout. I am not sure how you could not have seen an emphasis on this.

You people are ridiculous attempting to pick apart everything I have just said. Many of the things you are assuming are just wrong or you pick apart them even though you don't know the answer yourself. Mine is for the masses, so you counter with an example that most people aren't going to do. Like have a CB radio. Really, how many people here, even on a gas saving website, have CB radios for this purpose?


RED:
Yes. Motor Trend did a report on this 4 years ago. It is no longer on their site. If your tires bulge, there will obviously be less of a contact patch. Poor braking. Poor tread wear.


Regearing: Lower ratios (higher numerically) puts less load on the trans. Don't believe me? Fine, learn a little about cars.
AT Shutoff: It does cut fluid to the drum. 20,000 miles is a joke of reliability testing. I have personally seen race built transmissions grenade from doing this after a pass. They did it enough times and it just let go. It will simply take much longer with yours.
Battery instead of Alt:You're honestly arguing with me that its worth not having an alternator so you can make 2-3 20 mile trips?! How many people drive 5 miles to work each day without the radio or A/C on? What percentage of the population would be better served by this.
Weight Reduction:I am building a 1997 Mercury Tracer with a 3.0 Duratec whose goal is 30mpg capable and 13.99 at the track. That serious weight reduction is going to be a lot more viable solution. I thought it was understood in "requires commitment" that doing this is gonna suck ***.
Solar Cells: Really so you've measures how drained the battery is when your car shuts off right? You have some experiment to back this up? (Hint: My sense of self assuredness on this point is the result knowing and being able to defend my points here.)

Thisisntjared: LMAO I will try to keep my e-smug down to a less llama like level.

Snax: I don't care if you stick it in a giant rubber condom an SRT-8 is going to need to ditch the 3.55s it has, and well as lean out quite a bit in the A/F to achieve even a decent cruising mileage. Aerodynamic mods aren't gonna cut it.

Who is talking about oversize injectors? Most cars have injectors that are far from oversize and who are designed for fuel economy and longevity.

If you agree that the majority of something is true, consider that may be the point of the whole argument. For it to be true for the majority.

Fourthbean: "The consensus I have found is that electric windows are lighter than manual, I cannot find a definitive source on this but it makes sense in my mind." The logic of the other thread is full of stuff like this.

Also many of the second list of points were points not only on gas mileage but for cars interested in racing as well.

If you do not like my info, you don't have to use it. I was just posting it for the general good of people here. I have taken the ideas I want to take such as air dam blocking and wheel well covers and will try them. I think with the car I am building they will greatly benefit it. During those long drives to the beach. Thanks guys.

Whoa nelly! AT shutoff does not equal putting the AT in N, which you talked about initially. In N, most ATs I know of will still have fluid pumped through at a rate equivalent to engine speed. I can't see how occasionally shifting into N increases wear by more than a small amount assuming conservative driving. :)

https://www.theturboforums.com/smf/in...?topic=65025.0

Call a well known high performance automatic builder see what they say. Most people do not know this. L

You're talking about racing transmissions that are only designed to operate for a few high demand seconds at a time in a high power engine running at 140 mph, not a little old Honda slushbox at 55 mph. Many of us on this site have been doing this for long enough to know that it isn't nearly as bad as you claim. Did I mention that my car has about 130k miles on it and still has its original tranny? It's an older automatic. Most that I've seen don't last this long. The fact that I'm doing this and it hasn't died on me or shifted harder is a testament to the reliability of it.

Mine is for a secondary purpose but it does come in handy for this.

You should go wheeling once in a while. You'll notice there is a trend in the carnage that is directly related to the gearing run.

You'd be surprised what kind of abuse your battery can take before it completely craps out. If people are driving a mere 5 miles to and from work each day, and at the end of trip their rig sits for say 6 hours, perhaps hooked up to a solar cell are they even going to notice that they don't have an alternator? Long trips this would be a dumb idea, but if you can get from A to B and you are sitting at B long enough to recharge, its not going to matter.

My IOD is 30 milliamps.

Depends, I'm good for either 4.6l or 10 psi of boost on my stock injectors.

I'm going with repete86 on this one. There's a member on these boards who has called up Toyota and asked if coasting in N was o.k. wrt transmission fluid pressure and supposedly they said NP. I've been doing it for ~10k miles on a car w/ ~170k miles, so only time will tell I suppose. There's also a huge difference between the KE of a ~12lb drum on a th400 after a 100+mph pass and the smaller (?) drum on a fwd import at ~60mph. There could also be difference in the hydraulic/oiling system that make th400s especially prone to lube issues when put into N at high speeds. I'll see if I can hit up Toyota about this. So far, knock on wood, no one on this board has had any trouble.

What's ridiculous is joining a forum without spending enough time to get a good idea of what kind of people are using it and why. If you had, you would have realized that generating information that's strictly palatable to the masses isn't something that most members here care much about.

With due respect for the aim of (and most of the points in) your original post, and the discussion it generated, your forum etiquette kind of bites, on first impression.

thanks everyone
 

Glad you all like the list. If there's a better one, I'm all for putting it up. This one, however, I don't think is better. I put a high priority on convenience. I surely don't do everything on the list, but did want to try to at least mention everything worth mentioning and perhaps a few not worth mentioning, and try to rank them. Pumping up tires is easy, that's why it's at the top. Changing oil isn't too big a deal, and that's why it's near the top. Throwing out seats, however, is a definite sacrifice. I thought about things like walking instead of driving, but wanted to take it as a given that you had to drive (for whatever reason), and so this should be about how to get more FE, and not be about how to avoid having to drive.


spinningmarkviii: Sure would be nice if we had a lab full of scientists with time and money to carefully test out gas saving ideas and ferret out all the details of under what conditions a change saves gas or doesn't save gas, or has undesirable side effects like being too dangerous, or wearing out or damaging tires, engines, trannies, or causing excessive pollution, and so on. Of course we don't have such resources, but we can and do test out ideas as best we can.

Certainly the car industry hasn't made FE a priority, nor has the buying public, or perhaps there would be more research and less uncertainty. Maybe we'd have cars that automatically shut down when stopped and automatically and efficiently restart when the driver presses the gas pedal, automatics that are as FE as manuals so we wouldn't have to bother with clutch pedals and gear shifts, smart alternators that charge only when efficient to do so, and so on. And maybe we wouldn't have anti-FE marketing fluff like those worthless fins and spoilers that some people think makes a car look cooler, hood ornaments, or vinyl tops (meaning, a vinyl layer on top of metal), or just plain bad aerodynamics for the sake of looks. We do a lot of things manually that we shouldn't have to do manually. It's a pain. But you should do it if you want to get those extra miles per gallon.

Luckily, FE and performance often go together, so we can borrow a lot from the performance aftermarket.

Yes, toll roads should be freed. I've seen the horrendous backups tolling causes on the Dallas North Tollway. Even though most people have "toll tags", enough have to stop and pay cash that during rush hour they block up all the lanes anyway and force all those with toll tags to wait along with them. Also, a lot of people will spend the extra time and gas it costs to use the free service road rather than pay a toll. Toll collection further spoils the usefulness because a lot of trips that would make sense on a free road don't on a toll road. For instance, it's seldom worth getting on to skip just one light-- some tolling is so awkwardly set up you might have to stop and pay to get on, and stop and pay again to get off.
I prefer increasing the gas tax to imposing tolls with all their overhead an inefficiencies. I also prefer the gas tax from an incentive point of view. A Hummer pays the same toll as a Metro. No incentive there to use more FE transportation. I DON'T like it that every time I pay a toll, I'm in effect subsidizing someone else's extravagance. Those with lighter vehicles should pay a lower toll than those with heavier vehicles.

Don't you know why golf balls have dimples? Those dimples reduce drag. The same concept works on cars or anything else being pushed through air. I have seen dimples used on an electric car. Do you think they would have put those dimples on if they didn't help or didn't know whether they helped?

In my mind I believe I can get 30 mpg in my current car without much more money spent. Going diesel currently will cost me 20 cents more per gallon(may change once summer hits), any gasoline car that gets above 30 I would be afraid to drive. Unless it was a much newer vehicle in which case it would cost more and offset my gas savings. Gas going to 5 dollars a gallon will more than likely change my decision, but for now I will put my money in the bank :).

I was looking at the cost of a vehicle that I would feel safe in, namely a larger diesel car. ie. an older mercedes. In which case it would not apply to everyone, most people I have observed don't mind driving a small car but it scares me.

My take on the window weight is that a small motor would not need as many gears and bars to make a window go up as something that is mounted in a door panel, hence not weighing as much. But my main point is that it was stated as a fact and I believe it is still out for jury.

I should have put some links about this as making a claim and not defending it is stupid. Here is atleast something to help me out here :)
https://www.gassavers.org/showpost.php?p=47088&postcount=34

I thought I had seen a site on google talking about it but cannot locate it now.

It's been a while since I have gotten to discuss things like this on a forum, nice to have some other people to chime in with!

Excuse me for nitpicking, my defenses go up when someone comes in and claims superiority yet seems to offer nothing more. I appreciate and welcome any new information you can bring me and I will glean it willingly.

HAHAHAHAHA a racer telling hypermilers the what and not's.... LMAO

psy

Well, first of all I would like to say "welcome". You seem to have a lot of knowledge, and I think you would have a lot to offer this forum. So I really hope you stick around and participate, vs having some of us scare you off.

However, you really need to learn the difference between "having a good B.S. detector", and "having a closed mind". While it's good to be skeptical of some ideas that don't (on the surface) make sense (i.e. having a mind so "open" that it's essentially "empty" isn't a good thing), you really should try to "keep an open mind" until the evidence pro or con has come in (and been reviewed). Because a mind that is too closed to new ideas, really isn't a good thing either.

And on that front, I really feel we need to pick apart your opinion on the following (all related) topics you brought up (as the evidence really is "on our side" with these mods. which you listed as "retarded", "horrible", etc):
All of these mods are based upon the fact that virtually all electric power in a car ultimately comes from the alternator (the battery just stores up and buffers that power). And since the alternator is an electromechanical generator (that turns physical motion energy into electrical energy), it has to follow the physical laws that govern all electromechanical generators. And included in those physical laws, is the fact that you don't get something for nothing (you just get to turn one form of energy, i.e. mechanical motion, into another form of energy, i.e. electrical power), and the more electricity you need/get out, the more mechanical energy (which in a car translates to mechanical drag on the engine) you have to put in. So lowering electrical loads on the alternator (either by conserving electrical power in the car, or finding a different source of electrical power that can offset some or all of the power from the car's alternator) has to translate into lower mechanical drag (by the alternator) on the engine (the physical laws of nature don't allow any other outcome to be the case)!

So if you look at this critically, there really shouldn't be any doubt that lowering electrical usage and/or providing some other (non-alternator) source of electrical power, should translate to better gas mileage (because that will lower the mechanical drag the alternator puts on the engine, and due to that lower engine drag from the alternator, require the engine to use less gas to do the other work it is designed to do).

The only real question remaining, is how big is the benefit, and is it "worth it" (i.e. "cost effective") to go after that benefit. And that's where "doing the math", along with some easy practical (scientific) experiments, can really help to clarify things. And while the results are mixed as to it being "worth it" (it depends a lot on the details of how you are modifying things, how much electrical usage your vehicle is using, and even the current "price of gas"), these mod are clearly not "stupid" (something of an "engineering challenge" yes, but not "stupid"). Consider some of the facts already known (and shown) by various gassavers members:

1) It doesn't take much logic/reasoning to realize that the best possible fuel economy help you could hope to get by electrical mods (unless you convert more of your vehicle over to electrical power, and thereby lower the other drags on the gas engine even more) would be gotten if/when you eliminate 100% of your alternator's drag on the engine. Eliminating 100% if the alternator drag is the theoretical "best case" for these mods (if you were to manage to get 100% of the possible benefit from these mods). So it's helpful to know how big the gain could be. Thankfully there are two different ways to arrive at that "theoretical best case" number, that are easy enough for a talented "do it yourselfer" to do.

One approach is to just "do the math". The conversion factors between mechanical power (i.e. horse power used) and electrical power (i.e. watts used) are well known (just look them up in a good physics book). So the "cost" of that electrical power in the car should be "easily" calculated by simply converting the watts used (in the car) into mechanical "horse power" drag on the engine, and then further subtract out any conversion (efficiency) losses, and any storage (battery) losses from the number you previously arrived at, to get a rough idea of how much engine HP it takes to get the electricity you are using. The resulting number should be pretty close to "the real cost" of what your electrical power is costing you in lowered fuel economy (i.e. more gas used).

And the other way to arrive at this number is even easier. Just "run the experiment", and test how much less fuel is used when the alternator isn't hooked up. While it may not be practical to fully disconnect the alternator for long periods of time (unless some other source of electrical power replaces it), it's very easy/practical to disconnect the alternator for shorter periods of time, and just use the battery to supply the needed electrical power during the test. So this is a very easy test to run, if you have good instrumentation to measure fuel usage during the test.

And guess what? Some gassavers members have done just that (either "run the numbers" or "did the experiment", or both), and "the best case" numbers (if/when you could eliminate all alternator drag) seemed to come in somewhere in the 5% - 20% range, depending upon the exact makeup of the car, including how much electricity was previously being used in that vehicle. i.e. Fully disconnecting the alternator resulted in 5% - 20% (around 10% was common with a lot of vehicles) better "gas mileage" than the normal situation in a car. And while there are other things you can do to save even more gas, that tells us that there is still great potential to get better fuel economy with these mods.

2) Mechanical load (on the mechanical power source) of electrical generators (and remember, a car's "alternator" is such a "generator") is known (again laws of physics, not to mention many easy/practical tests can demonstrate this fact) to be proportional to the electrical "load" on the generator.

The main truth that fact tells us, is that even if/when we can't totally eliminate the power load on the alternator, lowering the load has to give us a proportional portion of our total "best case" benefit! And this also gives us a good way to calculate/estimate how much benefit we get, based upon the percentage of total "best case" electrical improvement we make. So we not only get partial benefit for achieving some percentage electrical improvement (either by lowering the electrical loads, or providing some other electrical power source to handle some of the load that the alternator previously was), we even have an easy valid way to calculate about how much benefit to expect from any given electrical change!

So at this point, the mods all come down to "running the numbers", and seeing in which cases it is cheaper (i.e. more "cost effective") to lower electrical usage and/or provide an alternate source of electrical power, than it is to just do the "normal thing" and let the alternator provide that electricity (which ultimately is paid for by using more gas for the engine to compensate for the additional electrical drag).

And that's where it is more of a YMMV thing. While not every approach that various gassvers members have tried ultimately was "cost effective" (some actually cost noticeably more than just getting that electricity from the alternator, by using a little gas in the engine), that doesn't make the idea "stupid". Rather, what it means is that we have an "engineering challenge" to produce (or save) the electricity by a means that is "cheaper" than the alternator produces that same power (by means of gas used by the engine). And there are several potential ways to do that, that are far from "stupid" (and have the potential to be very "cost effective"). And this "engineering challenge" (to be "cost effective" in producing and/or saving electrical power) becomes even more easy to meet, as the cost of electrical power from the alternator goes up (and as the price of gas goes up, the costs of electrical power from the alternator go up a proportional amount with the gas price increase)! For example:

A) If you have batteries that can meet all your vehicle's electrical needs for a day (or more), than you could totally disconnect the alternator (i.e. 100% of the theoretical benefit) and simply have some way (such as plugging the batteries into a charger when you are at home) to charge those batteries back up. The "costs" of this approach are the electricity to charge the batteries up (you have to pay the power company something for the watts of power you use at your house) along with purchase price (and "wear and tear") on the batteries used. Some gasavers members have "run the numbers" and discovered that this doesn't make economic sense with normal car "starter batteries" (due to how costly the "wear and tear" on such batteries would be, when used this way), but it can (at least in theory) be "cost effective" if the right "deep cycle" battery pack and charging circuits were to be used instead. Obviously, there is a real $$$ cost for "higher tech" batteries and charging circuits, but some combinations of battery technologies do show clearcut positive gains (over the expected life of the batteries), using this approach (which is hardly surprising, as this is just a smaller version of the electrical challenges faced by designers of pure electrical cars, and we know that such challenges can be overcome with the proper engineering)!

B) Conserving power is often cheaper than the effort to produce more power (even for homes connected to the power grid, and electricity generation in a car is considerably more costly, in terms of costs per killowatt of power, than the cost of home "electrical grid" power). And it's also true that (traditionally) users of car electrical power have been much more poorly designed (in terms of electrical energy efficiency) than many appliances in your home. For both of these reasons (higher cost per watt to get the power, and overall lower electrical energy efficiency of those consumers of the power), it stands to reason the "power conservation" on a car can be one cheap way to lower the electrical drag on the engine. This is one key reason why converting power hungry car (incandescent) lights over to energy effecient LEDs, can have an extra benefit of better gas mileage (in addition to their more pure color output, and the fact that they almost never burn out). And converting lights to LEDs is just the most obvious place to "conserve electrical power" in your car. And again, the more (percentage wise) that you lower your car's electrical load, the closer you will come to that ideal of disconnecting your alternator entirely.

C) And yet another way to lower the load on the alternator, is to offset some (or all) of the power produced by the alternator with an alternate source of electricity generation (that doesn't ultimately come from drag on the engine). And guess what? Solar power is essentially "free", once you buy (and install) the solar cells. And we all know that solar power can make cost effective sense (long term, over the expected life of the solar cells) even with a power grid connected house. And since the cost of electricity (from the traditional "alternator" approach) in a car is considerably higher than the cost of most "electrical grid" power, it stands to reason that the benefits in a car should actually be HIGHER (i.e. faster "pay back time") than in a house! About the only things to watch out for with solar are the extra weight and aerodynamic drag of the solar cells. But with quality solar cells the weight "cost" is pretty minimal (for example, you can easily get a panel rated for 20watts that weighs only 6lbs). And your "aerodynamic drag" cost depends entirely upon how you mount those cells (mount those cells correctly, and you won't increase the car's aerodynamic drag at all)! So solar is (surprising as it sounds) a potentially very viable (and cost effective) electrical power source to add to a car!

And has been pointed out in other forum threads, those aren't the only potential sources of power savings (and therefore gas savings) that you can do. But the main point is that once you realize that electrical power does cost some gas (i.e. is NOT free), you then have the tools to look for other means to meet that electrical need, and evaluate the "cost effectiveness" of those alternate approaches!

BTW:
Your description of the solar cell mod as "retarded" is actually pretty funny. As it turned out, I think I was the first person who proposed the idea on this forum (I guess that would make me "the head retarded one"?). And while I haven't yet personally purchased a solar panel for my car (although I plan to do so shortly, as I think I've now found which solar panel is a decent size for fitting in my car, produces enough power to be somewhat worthwhile, and doesn't cost a total "arm and a leg"), I have done other "electrical power saving" changes (including converting many of my car lights over to LEDs) with good results. And as far as me being "retarded", well...

As it turns out I'm far from "retarded". In fact, my intelligence is surprisingly high (it's been tested as being above the 98th percentile, if you were wondering). And while I'm not an electrical engineer by trade (I work with computers for a living), I none-the-less learned enough about electrical engineering in high school and college to have a real clue as to how such things work.

So just because the auto-industry has traditionally ignored the real "cost" of electrical power in a car (my guess would be because they have "always done things that way", so stopped looking at alternatives to that design), doesn't mean that there isn't a real "cost" that electrical engineering can prove is there. And using non-conventional means (such as solar cells) to lower the fuel cost of that electricity (especially now that gas prices are raising so much) can be worthwhile to do.

And really, anyone who thinks pursuing such gains is "retarded", is actually saying more about themselves, than the people facing those engineering challenges. As to me, I just laughed off your "retarded" remark, and shook my head. After all, science and engineering are on our side with this issue...

I'm surprised th BMFC chart hasn't been displayed in this thread :p

Okay... mechanics rookie here!! Help please... I know little to nothing about the inner workings of a car. LOL.

On my drive home, there is a substanial hill which I usually coast off of. The speed on this road is 55, and it's a two lane road. Usually the traffic is minimal so I can speed up to 55, shift into Neutral and let it coast. I get up to 70 or so, but I need the extra speed. My car is an automatic but it coasts really well. I let it coast for nearly a mile or so, since the latter half of the coast is 25 mph, so as you can see, the speed loss works perfectly into me maintaining the speed limit all throughout the coast. I think this helps greatly with FE, but is this something I should stop doing? I never shift it back into D once I let it coast.

Anyone with knowledge on this? It would be appreciated!

I've been doing it for a long time. He's flat out wrong. The instances he's citing are with drag racing cars with transmissions build for racing and engines that are designed to go past 50k rpms. If you drop into neutral with your engine going at 50000 rpms and your car going 150 mph, yeah, things will get ****ed up, but not at normal driving and engine speeds. Even shifting back into D is fine if you give it a rev match. The only issue is that if the engine is off, the tranny doesn't get lubricated, but there is more than enough oil left in the gears IMO to be able to handle EOC'ing for the mile or so that you do it. I EOC every time I get into my car and have almost 130k miles on my transmission.

Well I drag race a lot and I have seen stupid people blow their trans by shifting into N at the end of the run. The difference is the engine is off so the oil quits pumping in the trans. So obviously going 150mph in N with the engine off means death to the trans. If the engine is running then you can run in N all day long with no issues. I have actually done that towing an automatic :) I let the engine idle with the trans in N so I could tow the car with a tow dolly at full speeds on the highway. I towed it for 6 hours to get it home on the highway with the engine idling the whole time. The car went well past 100k miles after that and is still running after I got rid of it cause I see it on the road every once in a while.

I possibly will also be taking the alternator off my car this summer and going to solar panels :D Anyone serious about getting the absolute best mileage possible is going to remove their alternator and supplement their charging with solar panels, The assumption that it is not beneficial is silly. The only thing is it is pretty expensive so from a strictly economic perspective it isn't worth it. This summer my car will be long past being economic after everyone sees what I am going to do to it.

All of the gas saving idea at this forum are *your results may vary!* What works for one, may or may not work for another. Many of the concepts these people are bold and adventurous new ways to get better FE. You defiantly need to "think outside of the box" for some if these ideas. This forum explores and discusses them, like no other.

IE warm air intake VS cold air. It helps FE on some, others it decreases FE, according to testing by the members here. (IMO if the engine was tuned for warm that would help, but not easy to do) Anyway, I have owned 8 different cars and trucks in the last 4 years. They are different.

Man, no offence, can't you see, you are being hypercritical? You started this thread picking apart the "Best to Worst List."

Also If YOU didn't like the info on the stickies, you don't have to use it....... and so on.

*looks for it*
It's gotta be here someplace.:D

I'm merely suggesting that you look around at some of the real world results some people on this board are getting with aerodynamic mods. The SRT-8 has lots of room for improvement on that front that would not require swapping to a higher rear end ratio or leaning it out. If only I had one to play with. :)

Ok, I'll grant that this is an issue of perspective and elaborate further:

Virtually every car on the road these days utilizes oversized injectors relative to what is needed to sustain highway cruising speeds. I can't quantify it exactly, but it's clear that most cars can cruise at well below 1/3 to 1/2 of their rated horsepower.

Obviously the injectors are oversized to provide for acceleration. Better fuel economy can be attained by simply sacrificing some of that accelerative capacity with smaller injectors, providing finer resolution. (NOTE: I'm not suggesting that the DIY'r throwing in smaller injectors by themselves will have positive results without remapping the fuel.) It's a simple compromise that manufacturers make to keep performance and fuel economy up to levels that consumers expect.

Virtually every car on the road these days utilizes oversized injectors relative to what is needed to sustain highway cruising speeds. I can't quantify it exactly, but it's clear that most cars can cruise at well below 1/3 to 1/2 of their rated horsepower.

Obviously the injectors are oversized to provide for acceleration. Better fuel economy can be attained by simply sacrificing some of that accelerative capacity with smaller injectors, providing finer resolution. (NOTE: I'm not suggesting that the DIY'r throwing in smaller injectors by themselves will have positive results without remapping the fuel.) It's a simple compromise that manufacturers make to keep performance and fuel economy up to levels that consumers expect.

I don't agree that injectors are too large. Maybe the cars are too large, the engines in them are too large, but making the injectors smaller isn't going to have an impact on FE. The auto manufactures are trying to balance making HP and pass emissions. They are selecting the minumum size injectors that will supply enough fuel at WOT and not be at 100% DC to do it. They also have to keep the car somehwere near a 14.7 AFR to meet emissions. Smaller injectors would just be running harder to do the same job. To get better FE, the cars would have to weigh less, have better aerodynamics, and have smaller engines. So far the comsumers are not demanding this. But considering I just paid $3.57 for regular in San Diego, maybe this will change.

Sigh.

I'm not so sure that you can draft in a way that's legal. Not a close draft anyway - which is the kind that really helps mpg.

My point here is that I believe close drafting is illegal, at least in most states. Legal following distance is usually two seconds worth of travel distance, or one car length per 10 mph of speed. And since the car length version goes back to 1969 when I took Driver Ed., you'd have to count a car length as 18 feet or so. An effective draft at highway speeds is maybe 1-2 car lengths behind a semi, and that's far less than the 6 car lengths that would be appropriate for 60 mph.

I put a premium on safety. I'm much more comfortable with a following distance of 2-3 times the minimum legal basic.

<--- Runs and gets popcorn :D

What I said: "Virtually every car on the road these days utilizes oversized injectors relative to what is needed to sustain highway cruising speeds. "

That's not the same as saying that injectors are too large, only larger than needed to sustain cruise. And yes, injector size does make a difference. Smaller injectors produce finer atomization as well as finer resolution, and that produces a more efficient and cleaner burn.

I think Spinningmarkviii left....

Wow, I have found this thread very enjoyable. I think the $3/gal gas is bringing new people to the site.

Hrmm... That's actually quite interesting... Worth some research methinks... I wonder if the headloss from smaller injectors (thus requiring longer duty cycle) outweighs any losses from "larger" sized injectors (in quotes because I'm not talking about 300cc differences)... Kinda like hydraulics I'd think -- what's more important - Flow or Pressure? Well, both are pretty equal :p

Increasing aerodynamic efficiency will give better FE, some spoilers will do this, some wont. Without a wind tunnel to test, its not easy for average joe to test them. Maybe with FE readings...