The size of the engine will become insignificant in the future, because the engine will not be directly connected to the powertrain.

Capacitive storage of the engines energy production will allow you to store 1000 horsepower-seconds of energy, to be applied to the wheels as needed.

Make a mental graph of the real time power demands of your vehicle, then understand you must have a sustained power capability to climb steep grades.

Its not the oversized engines that are the real problem. It's running them all the time, and running them inefficiently almost all the time. The engines most important quality is its BFSC regardless of its size or power.

The failure in current designs is the belief that you need to use the engine to drive the car, which costs you 50% of it's potential efficiency.

regards
gary

nobody is saying that. they said they are going to add weight to test the difference.:thumbup:

actually it seems several people are. Adding weight will ALWAYS hurt fuel economy some, but if you are improving other variables more then the weight increase contributes to fuel economy, then yes, you will have a net increase in gas mileage.

If you could add weight to increase fuel mileage, everyone would be placing concrete blocks in their car year round.

Also I believe basjoos car did gain much if any weight, he chopped off some significant metal, removed glass, and replaced it with aluminum, lexan and I think abs plastic, which is probably considerbly lighter.

LOL, in the winter I used to keep about 200 pounds of lead plates in the bed of my 74 chevy for snow traction. Otherwise it didn't go anywhere in the snow.

-jay

Yes, but it's always never nothing.

(said theholycow as he ran off into the sunset, laughing maniacally)

Ok, Jack, Janet, and whatever we're calling the hot blonde this season - we better get this figured out before Mr. Roper gets here... ;)

For what it's worth, my drives with the wife and child on board are consistently about 5 mpg lower than when I'm solo. Low 60's solo, high 50's with them.

holy cow,

never and always are dangerous words. and yes, my statement sounds like something off of a bad cat and the hat spoof.

it's never always the same
but who's to blame
could it be the cat
but he is stuck in the hat
why not wait and see
then you'll find out it was actually me.

What's responsible
I don't know is at fault

My MPG always goes down with passengers. I usually don't hypermile as well because then I have to constantly explain why I just shut the engine off, why I just shifted into Neutral, why did I just downshift in an automatic, why am I driving so slow...

-Jay

Jay2TheRescue: I try to make it an educational experience. ;)

Yeah, but some of the people I associate with think that hypermiling is crazy, but then they marvel @ my MPG knowing that I drive mostly in stop & go city traffic.

-Jay

perhaps a flier attached to the passenger dashboard explaining all about hypermiling. it would keep them quiet while you are busy saving fuel.

How about something like this affixed to the passenger side of the dashboard...

https://www.fuelly.com/attachments/fo...f00fd375bf.gif

briliant

Printed and pasted to glove box

who??

You might want to fix the misspelling. It's "engage". And "brilliant"...though that one's not getting pasted to a glove box so it doesn't matter as much.

weird my spell checker didn't catch that.

I pasted the Warning sign on my glove box.

Sorry, my spell checker didn't catch that either. Sorry about that. My bad. I'll fix it.


-Jay

EDIT: Its fixed now. Everyone do a CTRL+reload

Did a controlled test on Sunday, driving to church with the family on board. That's about 200lb extra. 57.4 mpg there, 55.1 back. My average for that route, driving solo, is 63 mpg. I hypermiled it to the best of my ability, and weather and traffic were simply perfect.

+200 lb (+9% weight) = 11% worse MPG.

That may well be the first time I've ever seen hard data from an actual experiment. Bang up job!

This pretty much confirms what I've been saying all along -- you need a significant perecentage of weight difference to make a measurable FE difference. Taking 50 pounds out of a 3000 pound vehicle will simply not yield a worthwhile increase (unless that 50 pounds was just wasted space).

So, if you have a 2,300 pound Civic, and you think you can yank out two hundred pounds (more than you'll get from removing the backseat, trim, spare tire, and buying wheels)...go ahead. It might be easier to just drive around with never more than half a tank of gas, which weighs ~6 pounds per gallon.

Can anyone else provide hard data for different types of vehicles? The effect may differ in vehicles with different power-to-weigh ratios, for example, or different MPG-to-weight ratio...

see earlier posts about 5 people in a Grand Prix going over mountainous roads at 55-75mph. 3300lb base, 155lb avg. each person. approx. 200lbs baggage. 380 miles, 34mpg.
With just me and the wife (-3 people) It was 34.88mpg.

so, approx 4275lb in my car net me 34mpg.
3600lbs net 34.88mpg.

Same speeds, same techniques, same distance, same time point to point (almost exactly, off by a couple minutes).

So, where is my car's most efficient power/weight? seems its a pretty broad range for highway cruising.

That's a mere 2.5% change in MPG (seems to be within a reasonable margin of error) for a whopping 19% change in weight. :( That surprises even me.

I know this sounds like approximately the same thing, but I'd really like to see the difference when a car designed to weigh X pounds has its weight reduced to X-Y pounds, rather than when its weight is increased to X+Z pounds. That's much more difficult to test, since significant weight reduction is so difficult.

the problem with an experiment like you described is the money associated with it.

you said before (and I agree whole heartedly) taking out the seats and the spare isn't really that much weight. the only way to do the experiment that you describe is to start replacing body panels with fiberglass or carbon fiber.

I also would like to see the results of a test like that. I once priced a carbon fiber hood for my truck (to make it faster and look cool) to the tune of around 2K. maybe it was where I was getting it from, maybe that is typical, I don't know.

Wow.....really an insignificant difference 675lb makes. Not worth the hastle of taking any necessary items out then.

When I someday get my protege running, I'll put the stock weight back in, probably with some dead weight. I'll run it for a while to get a baseline. I'll then remove the weight to its current stripped out set, and run it again. That'll give me an idea if removing the 300lbs made a FE difference, or just a handling difference.

btw, I have to add the weight back in for the baselines since it has a new motor and different tranny than it did before, so past numbers are meaningless now. It may be a while......

i think the two different experiments show that its different for every car and some cars will significantly lose mpg with added weight, where others may not even flinch. the same is true for removing weight.

when i had my d16z6 in my 94 civic hatchback i was getting mpg that a normal 94 si would never get. granted my hatchback weighed over 300lbs less than the si model of that year.

When I had my metro I stripped about 120lbs off of it and noticed a major difference. That is just MY car, so I can't vouch for others, but 120lbs on an already light car made a difference. Since the car was underpowered on hills, it had an easier time going up them. Actually, that much weight was enough to completely change my shifting pattern. On a hill near my gf's I had to make it scream in 2nd becuase it was so steep and it would dog down in 3rd. After I changed it, I could easily scoot up the hill in 3rd with low rpms.. I would drive up my street in 3rd with moderate rpms. After the weight loss, I drove in low 4rth.

I definitly noticed a gain in mpg AND overall speed, so noone can tell me it doesn't work:D

[QUOTE=thisisntjared;121325]i think the two different experiments show that its different for every car and some cars will significantly lose mpg with added weight, where others may not even flinch. the same is true for removing weight.
QUOTE]

My dad's H2 Hummer didn't budge at all when we towed at 18' speedboat to FL from MD...

Perhaps the pattern is that vehicles with power to spare (like that Grand Prix) won't show a measurable difference, but underpowered vehicles like that Metro that could barely get up the hill will show a difference proportional to the precent of weight removed.

I totally agree with you holycow. That's why I need to test the protege, as the old 105hp motor had a hard time moving the awd drivetrain and 3000lbs with just the driver. Since it weighs closer to 2500lbs now (empty) I feel the more powerful motor--125hp--should net me a large increase in FE; assuming I keep my foot out of it :)

I entirely agree. The family vehicle, a V6 Odyssey, returns very similar mileage whether it's empty or loaded with 6 people and gear for vacation. My Civic, with it's 106 horsepower, is a different story. Torque? there is none.

My old Bonneville wagon actually got its best mileage with 5 people, 1 dog, and a weeks worth of luggage. Then again it did have a big block V-8 so loaded and cruising on the highway it was closer to its peak torque and pumping losses were minimized.

-Jay

Another data point, from a different thread:
There's not a lot of detailed data backing that one up, but it's interesting to compare to this post from earlier in this thread: