mpg vs. speed - Metro graph

[DonEaston]

Ahhhh yes, you feel my pain!

My father in law came down with his big plow last year and made banks on either side that were about 3.5-4 feet tall.

Well.... you want to guess how tall the drifts were the next day? Uhg!

I'll have to get some pictures some time. Three times last year I had to use the GMC to literally pull my car through everything to the end of the driveway to go to work (back when I was still a tech consultant).

The problem is that there is Nothing to block the wind or snow for about two miles to the west, then RIGHT on the east side of the driveway, there's a woods.

Okay.. rants over!

Pat

[roflwaffle]

Originally Posted by MetroMPG

To see if it gets better still than the taller final drive? I hadn't considered it (mostly because I don't know anyone with the same bolt pattern - 4 x 114 or something).

Pretty much. It looks like engine eff is increasing proportionally to the car's energy requirements increasing. Ideally, if your engine is operating at peak eff at ~55mph, it should be more like the other maps you posted from GCC. Maybe I'm being too optimistic but I think you still have way more available in terms of mileage at a slow highway cruise w/ your setup.

[shanelabs]

Great thread. Yeah, it's crazy how much speed affects your mileage. For those that don't believe, check out http://www.mpgforspeed.com/ It has a calculator that will show you exactly how much you can save.

[IndyIan]

Its interesting how the graphs have a linear reduction in efficiency and not a exponential reduction. I guess for an electric car we would get graphs like the ones I've attached. I thought a internal combustion car would still have similar results but I guess not.
Ian

[co_driver]

From my previous car's owner's manual, drivers were enlightened with the attached little tid-bit.

This was in the 1956 Beetle owner's manual. And, I believe in prior and very few subsequent years.

It shows a litres/100km (un-labeled) vs. speed graph where the consumption goes up (nearly linearly!) as speed rises. As well, there is a weight penalty plotted!

Note: the maximum speed of these cars was/is 68 mph!

[First post... Glad to be part of the movement!]

[MetroMPG]

Great first post, co_driver. Nice image.

Got to love the language in that manual:

"If you attach particular importance not only to the economy of your car, but also to a fair average speed, it would prove of value to make a compromise in the choice of the cruising speed in the interest of fuel economy."

Welcome to the forum.

[ebacherville]

Originally Posted by TomO

I like the presentation of the info. Makes it easier for others to see that if you slow down, you use less gas.

Now only if I could get away with driving 40MPH on the Highway. In MN, the lowest allowable speed on the highways is 40mph, but that is asking for serious trouble since most people go about 10MPH above the speed limit.

Example:
55mph limit means go 65
60mph limit means go 70
70mph limit means mash the go pedal till you see God, then slow down a little.

Yeah I'm in MN also.. in rural mn its like more like 5-10 mph depending on the driver, then again cops will give a ticket if you 10 over no questions asked... but the twin cities is nuts.. go the speed limit and people are flying by you like your standing still.. but there cops usually just go after the "boy racer" types.. the ones thinkingthe roads are race tracks.. and leave the 10mph overs alone