bates's Forum Comments
Showing comments 61-75 of 75 by bates.
100,000 fuel-ups!
I don't know about the rest of the Country and World, but in Southern California we get increased fuel economy in the winter due to the so called "Winter Blend" fuel which has better BTU's per pound and gallon than the "Summer Blend" This year has been somewhat better for me with the summer blend, due in large part to the extreme rise in gas costs in June and July which encouraged me to drastically reduce my commute speeds, therefore I didn't realize the percentage increase in my fuel mileage that I have in the past when the gas switched back to winter gas. Also, I think the Ethanol is a factor, in the past as I understand it Ethanol was a Summer Blend additive which doesn't burn as well as gasoline thereby hindering fuel economy, now that it is a federal mandate to have 10% Ethanol there isn't the drastic difference between the winter and summer blends, but this is just my guess, I don't have any facts or data to back that up. Purely my experience and applying my understanding of fuels and ICE's.
Also for the question about the variance in fuel economies between similar makes and models even within the same year, I think that there are a lot of factors there that are well beyond the control of the moderators. I put in my comments section whether or not most of my mileage is commuting, as commuting helps me increase my mileage. There is also the "Ricky Racer" factor, where some drivers are going light to light with hard accelerations and braking, which destroys your fuel economy over a tank of gas. I've been adding the commute or around town notes for my own personal help, but the moderators might want to consider adding it as a suggestion if the members are interested in it. I know that there was some discussion of and dismissal of the idea of providing an input to estimate the amount of highway versus city driving that were involved in a tank of fuel. That would be easy for me to guess, since I know exactly how long my commute is but I see how it would consisit of mostly WAG's for many members.
Keep up the good work guys, I love the site and appreciate all that you do for us here.
posted by bates December 3, 2008 at 6:33 PM
Avg. Time Between Fill-ups
I drove a 120 mile round trip commute in a 1967 VW Beetle for a little over a year, fortunately Southern California doesn't get awful weather like most of the country but that car could get cold and miserable in the winter, especially when it was raining.
posted by bates November 20, 2008 at 10:46 PM
Can I trade with VWJunky or Dave? I drive 90 miles round trip daily for my commute. I'd love to go 2 weeks between fuel ups.
posted by bates November 18, 2008 at 9:31 PM
Synthetic motor oils and MPG
rem83,
I agree with you for the 09 Sonata application, that is why I put the disclaimer to check the owners manual for the final word. I don't know of any cars manufactured since the turn of the century that allow single grade oil. In spite of my preference for single grade oil, I use multi grade oil in my 2000 Acura Integra that is my daily commute car, and my wife's 2005 Mazda MPV gets multi grade synthetic per the owners manual to ensure warranty coverage. My comment was more general and if it was not clear, then I appologize, I only meant that older cars that are driven in specific climates with more or less constant starting tempertures may not suffer from the use of single grade oils which tend to have slightly better break down performance due to the oil being made up more of oil and less of additives than multi grade oils, and they tend to be substantially cheaper than synthetics.
Every application is different, I was unaware until VWJunky posted above that some manufacturers vary the requirements even among the same model line to be specific to the exact engine installation. I do know that reciprocating aircraft engines mostly specify single grade oil and many Marine Diesel (boats not the USMC) applications do the same. Again like VWJunky pointed out, there are also very specific coolant requirements in some diesel applications as well. With coolants specifically designed to resist water pump cavitation which can produce bubbles in the coolant that may lead to hot spots in the engine or in extreme cases to holes in the cylinder linings as was the case with a boat that I used to run. That boat had to replace a large diesel engine because of pin holes in the cylinder linings caused by cavitation of the coolant pump which was due to the retailer not adhereing to the manufacturers requirements for coolant. The engine had also blown 2 head gaskets due to hot spots caused by aerated coolant not dispersing the heat as effectively as non aerated coolant would. The boat owner ended up having to pay for the replacement as the engine although only having a little over 4,000 hours total time (the design life expectancy was about 20,000 hours) was over 10 years old when the holes were found. There wasn't enough money in it to hire a lawyer to sue for damages with that much time passed.
posted by bates November 14, 2008 at 3:52 PM
The modern synthetic oils have come a long way from their founding brothers and sisters. I haven't noticed a significant change in mileage between synthetics or natural oils in my experience. I have had similar problems to what VWJunky reported with synthetic oil added to the gasoline in a 2 stroke motorcycle that I had back in the mid 1980's. A friend gave me some new 2 stroke oil to try and being perpetually broke and cheap, I gave it a try. It worked fine in the motor, but the gas line started to weep after a few weeks. This was the old neoprene hose that had a braided cotton over weave and it made a mess with black goo dripping on my motor and frame. The oil worked fine, but at that time there wasn't any hose that would hold it so I returned the unused portion to my buddy. That being said, I think the biggest problem was the chemistry of the neoprene fuel lines in 1985, not the oil, it was just so slick molecularly that it weeped through the hose.
Another alternative you might want to consider is using a parafain based traditional oil. With the wax base as opposed to an asphalt base you get an extra 15-20 degrees before breakdown as the parafin is a ring based carbon chain and when it breaks down at a higher temperture, it turns into a straight chain. The asphalt based oils are straight chains to begin with, when they break down you have serious trouble on your hands. I used Penzoil exclusively in my dragsters for that reason with good results over several seasons of racing. I never scattered a motor due to oil breakdown or lack of lubrication. Also, if possible use a straight grade of oil, say 30 weight as opposed to a multi grade of say 10W50 since the multi grade has additives that change the oil so that it will act like 10 weight when it is cold and 50 weight when it is hot. If you drive in similar outside air tempertures throughout an oil change cycle a straight weight oil will actually lubricate and cool better than a multi weight. The caveat here is that many manufacturers require multi weight oil for modern engines so if your owners manual dicatates that you must use a multi weight, don't take a chance on voiding your warranty based on my advice.
posted by bates November 13, 2008 at 5:51 PM
Coasting down hill
miataz,
Cruise control is a different situation and I don't know if the coasting would apply with Cruise control activated and as VWJunky mentioned your 93 year model may or may not have the electric fuel cut off that the article refrences. I also agree with VWJunky that driving down hill at 88 MPH in neutral is dangerous regardless of what your fuel economy results are. Remember that cruise control is designed to maintain speed and will meter the fuel delivery in an attempt to maintain a steady speed, that is different than coasting where you just remove your foot from the accelerator pedal.
posted by bates November 7, 2008 at 4:16 PM
Ann,
Car and Driver's current issue touched on this very same topic and reported exactly what Furrner said above, that modern (since 1990 according to the article) EFI systems completely cut off the fuel flow electronically in an automatic when the computer registers a difference between the engine RPM's and the transmission tail shaft RPM's for the given gear, in plain English, the computer recognizes that the car is coasting and shuts off the fuel delivery. This will provide the best possible fuel economy as VWJunky posted that his scan gauge shows. It also will cost you the least over all in the long term in the form of lower repair costs for both your transmission and your brakes.
Also like VWJunky points out the best fuel economy improvements are generally made by keeping your speed down and eliminating hard accelerations and braking. Remember that the old dreaded Double Nickle was enacted in response to the gas crunch of the 70's in an effort to reduce gas consumption. Like it or not it really does provide nearly the most optimal mileage results for most vehicles. Honestly the best mileage improvement I've had in the last 6 months was when the gas costs went ballistic in June and July and the average freeway speeds in Southern California dropped significantly so that the commuters would lessen their weekly gas bills. For me my average commute speed decreased from an average of about 70 MPH down to about 55 MPH and my average MPG went from around 27 up to 33 almost over night. So decrease your speed, inflate your tires, remove excess weight from your trunk, clean up your aerodynamics and coast down hill and I'm confident that your mileage will improve significantly.
Good luck and keep us informed.
posted by bates November 5, 2008 at 5:17 PM
Performance mods for economy
Years ago, long before smog laws, I had a VW Super Beetle that I rebuilt to improve performance over the 1300 CC motor that was in it. I put together a 1600 CC engine and put rebuilt heads on. I didn't notice at the time but the rebuilt heads had small intake valves (there are at least 2 standard sizes, maybe more) and the original engine had larger valves. I realized a fair improvement in acceleration (not very hard to do from the 1300 CC engine) and significant increase in fuel economy. The car went from about 26 MPG to over 30 MPG on the freeway. The funny thing here was that I thought I was hot rodding it, with no intention of increasing mileage, that was an accidental and inadvertant side effect of replacing the motor and I didn't realize until months later why it had happened. When I dropped the motor and took off the heads to check the ring break in I saw that I'd put heads on with obviously different valves. After I discovered what I'd done, I started talking to some VW performance enthusiasts and tuners and found out that I was just an idiot, they'd all been doing it for years with their daily street legal drivers for that reason.
On my 1988 Yamaha FZ600 I switched the carb jets for added performance and realized some increased fuel economy at the same time. That time I knew more about what I was doing. I increased the size of the secondary jets but DECREASED the size of the primarys. It seems counter intuitive but by increasing the secondary's you get the fuel delivery that you are after when you roll on a handfull of throttle. Downjetting the primary gives you less delivery at idle and when you aren't on it. That works out to better fuel economy at cruise and steady power settings like on the highway or freeway. The caveat there was that the increase wasn't huge, something like 10 % and was easily off set or even over ridden if I did a lot of light to light hard accelerations which burned fuel at a substanitally higher rate than the stock jets did. But what fun it was to ride that bike around with the added power provided by the jets and a high flow / low resistance tuned exhaust system. 103 Horsepower on a 400 pound bike worked out to mean that the front wheel was only on the ground when I was braking if you know what I mean.
For Hondas you can check out a company called Jackson Racing, they are located in Huntington Beach CA and have an online catalogue. They have some performance products available for sale that may increase fuel economy as well. Be careful of swapping chips as that violates many smog laws and may result in serious fines if you're caught. That being said a buddy had a 1990 Chevy Camaro with a 305 V8 in it and he switched out the main chip to a off highway only chip that gave him marginally better fuel economy but a significant horsepower increase all for a little over $125 and about 20 minutes worth of work to remove the stock chip and replace it with the new one. But with the added power he started replacing his rear tires a lot more frequently as it was a lot easier to light them up after the change.
Good luck and have fun.
posted by bates November 1, 2008 at 3:55 PM
Coasting down hill
It shouldn't hurt the transmission per sey but it will add wear to your transmission by shifting into and out of gear which will ultimately reduce its' life expectancy as that is partially linked to shift cycles. Most modern cars will switch to a high idle when coasting with an automatic transmission and really the difference between say 700 RPM's at idle and 1,500 at high idle are going to be too small to measure in the form of fuel economy. The only factor here that I see that might be measureable is compression braking, where the car slows due to the compression cycle of the engine where each cylinder goes through a compression stroke every 2 RPM's and that translates into braking through the transmission if the torque converter and the clutches haven't disengaged. So basically what I'm saying is that if you are coasting down a long grade then you might consider shifting into neutral to reduce the compression braking, but for day to day driving the only difference that you'll likely see is a shorter TBO (time between overhaul) for your transmission.
Since we're on the topic I should mention that in California at least, and I suspect that most if not all other states have the same rule, it is illegal to drive in neutral. That being said I can't imagine that you'd ever be caught doing it unless you were stopped by a LEO and were questioned on it or offered the information to the officer. Just an FYI.
Finally, make sure that you are changing your automatic transmission fluid regularly. This is one of the most commonly overlooked bits of regular preventative maintenance items that can be really costly if ignored. I do mine religiously at 15,000 miles even though the Acura service manual requires it only every 30,000. Honda and Acura have smaller than average transmission filters and if they clog then you buy a rebuild. I'll spend the extra $ now and get it done regularly rather than have to pony up for a full rebuild before it has seen the end of its' usefull life. That is just my $0.02, so take it for what it is worth, but I've built a lot of motors and a few transmissions over the years so I know at least a little bit about what I speak.
posted by bates October 30, 2008 at 8:55 PM
Need help.
Check the door frame, low on the aft (rear) vertical pillar or post, that is the most common place for the sticker. That being said, my 2000 Acura Integra's recommended pressure is 36 PSI. I've been buying tires rated for 44 PSI, I find that 44 PSI is an acceptable ride for me and tend to inflate the tires to that level, it does help some with mileage to keep your tire pressure high. My wife doesn't like the ride in her minivan when I inflate hers to recommended pressure so I tend to run hers at about 40 PSI, harder than the 36 that Mazda recommends, but less than the 44 that Michelin rates the tires for. As for wear, you'll find that your tires will wear better at a higher pressure as long as it doesn't exceed the rated pressure for the tire. If you run 44 PSI tires at 32, you'll experience shoulder wear and your tires will require replacement due to tread wear before the center of the tread has worn out. If you over inflate your tires you'll experience center line wear and the middle of the tread will wear out before the shoulders do. Properly inflated tires should wear evenly, with the shoulders and the center of the tread all nearing the wear marks at about the same time. Also, don't forget to rotate your tires, check the pressure at least once a month (and always check your spare at the same time) and get them in for a balance if you get any feedback from the steering wheel, especially when braking. A balance is a lot cheaper than a new pair of tires and an unbalanced tire can wear severely in just a few thousand miles.
Good luck, don't be afraid to try a little higher pressure and see how your car rides and feels. If you don't like it you can always air down back to your 32 PSI, just make sure that you add air and check the pressure when your tires are cold, first thing in the morning before you drive the car. The pressure will increase after driving and give you an in accurate reading.
posted by bates October 22, 2008 at 7:03 PM
Sort by Number of Fuel Ups
I live in Southern California so for me weather doesn't have much of an effect on my mileage other than a slight reduction during the summer when I run my air conditioner more often. But the seasons do make a difference in my mileage for another reason. We have "summer blend" and "winter blend" gasoline here. The summer blend as I understand it has more oxidizers in it, and my fuel economy suffers substantially when it is in use. I normally see a decrease of somewhere along the lines of 15-20 % in my mileage when So Cal switches to summer blend and a similar increase when we switch back to winter blend. This has been somewhat less pronounced since California went to mandatory E10 gasoline a few years ago, but it still is evident in my fill ups. I realize this is off topic for the original post, but following the comment trail here I thought it might be germaine to where it has gone. That being said, I don't think that the amount of time since a poster has logged in or added a fuel up should matter to their mileage figures, but it might make the graphs appear better or worse than the average if the date range isn't taken into account. As it stands the dates are graph points on the mileage charts so it shouldn't be any issue, if the numbers don't match your personal experience check the date range and see if that helps to explain the discrepancy. Just my $0.02.
posted by bates October 22, 2008 at 6:52 PM
What is FULL on a motorcycle tank?
While I don't have a street bike right now when I did I would fuel from on the bike. I would straddle the seat with the bike vertical and reach over to the pump to remove the nozzle, select the grade, and pay at the pump. That way I've taken as much variable out of the fueling process as possible. When you lean the bike over on the kickstand the forks and rear shock may not extend the same amount every time which adds a possible variable factor. Also, with a relatively small motorcycle tank by leaning the bike to the side you are giving up some of your limited fuel capacity. Good luck and do what works best for you, if that is leaning the bike on the kickstand, then great, or if you want to try to fuel it in the verticle position and maybe get yourself a little more fuel into the tank and a more exact fuel fill that will take some of the difference out of your mileage calculations.
posted by bates September 23, 2008 at 9:18 PM
Is my math correct?
Another concern is sediment in the tank. When you run a tank totally empty or nearly empty the percentage of sediment in the fuel increases dramatically. If that sediment is picked up by the fuel pump it will travel to the fuel filters, most modern Honda's have a primary fuel filter and a secondary one. If those filters clog you'll have to replace them and even worse if some of that sediment gets through them you could clog your fuel injectors which can be costly to repair or replace.
Finally if you decide to go ahead and see how much fuel is left after you hit empty on the gauge (BTW, you don't mention if you have a gas light on your dashboard, on my Acura that is supposed to illuminate when there is only 2 gallons remaining in the tank) bring a jerry jug with a gallon or two of gasoline in it so that if you do run totally out you have that to get you back on the road and to the nearest gas station.
Good luck.
posted by bates September 13, 2008 at 6:29 PM
50MPG coming in 2009!
From 1986-1988 I drove a Volkswagon Dasher Diesel station wagon. Man I'd kill to have that car back today. It got 50 MPG across the board whether on a series of around town shopping trips or a 700 mile long surf trip on the highway with two stacks of surfboards on the roof racks. I suspect that today I'd do quite a bit better on the road since I wouldn't be toting around the surfboards anymore and my driving style has become quite a bit less agressive. Even adding in for the modern low sulfur diesel I would bet that I could regularly see mileage figures well above 50 MPG for my 90 mile daily commute.
I am anxiously awaiting the arrival of the new diesels and will seriously consider one for my next car. Even with the premium that is being charged for diesel fuel these days the increased mileage will more than make up for a few extra cents per gallon at the pump.
posted by bates September 11, 2008 at 5:08 PM
All about acetone in fuel
acirrone,
The reason that Ethanol decreases your mileage has little or nothing to do with surface tension, it is due to the much lower BTU (British Thermal Units) content per weight and unit volume than gasoline. A 10% Ethanol (E10) gasoline mixture drops mileage substantially due to the Ethanol's lower BTU rating (the amount of energy stored in fuel that is released in combustion). In my 2000 Acura Integra when Southern California goes to "Summer Blend" gas for Air Quality Management District rules my mileage often drops by as much as 20%. The only good news is that it recovers upon the return of "Winter Gas" 4-5 months later. The Ethanol has been added to Southern California gasoline for quite a bit longer than the rest of the nation due to the outlawing of MTBE which was used in very small quantites per gallon only to be replaced by Alcohol, I believe it was originally Methanol, in quatities of up to 15%. From tracking my mileage I could literally tell you the exact date that I got my first tank of Summer or Winter Gas in my freeway commuter.
Also, while I don't remember my chemistry as well as the previous poster does, I can tell you that Acetone is a very polar solvent and it does disolve many plastics quite effectively so I wouldn't put it in my gas tank even with the promise of added mileage. As it is we are all going to be paying the price for Alcohol in our tanks as Alcohol is attracted to water and many fuel system components in older vehicles are steel based. Add water to a steel system component and you inevitably end up with rust which will play havoc on fuel filters, not to mention injection systems, fuel rails, fuel pumps, and combustion chambers.
Finally, I believe that you can find some non alcohol gasoline for off highway vehicles. The last I checked so called racing gas formulated for non street legal motorcycles, dune buggies, ATV's and the like did not contain so called oxygenators. Also AvGas for airplanes still contains Tetra-Ethyl Lead in some mixtures like 100 LL which stands for 100 (apparent) octane Low Lead, it is also referred to as "Blue Gas" due to the blue tint that is added to the fuel after refining as a visual reference to pilots that the appropriate grade of fuel has been used to fill the aircraft. It may be difficult to find an airport fuel company that is willing to sell you gas though so I'm not sure that it would be a viable option. I used AvGas for an old outboard motor on a ski boat after California outlawed leaded gas back in the late 1980's as the soft exhaust valve seats would have been ruined by unleaded gas in short order. It was cheaper to pay the high cost of "Red Gas" which was 80/89 octane at the airport than it was to replace the valve seats in that engine.
posted by bates September 11, 2008 at 4:54 PM