mpg vs. speed

[MetroMPG]

Originally Posted by krousdb

I suspect that since the automakers have knowledge of what the test routine is for EPA, that perhaps they "tune" the engine and transmission of the high FE models to produce the best EPA results, which helps to sell the high FE models.

sounds like a good theory to me. my last 3 tanks would have me at 29% above combined epa.

let's have a look at basjoos' numbers: he's about 20% above EPA @ lifetime mpg. if you just look at his 3 most recent tanks, roughly 62-ish, he's about 38% above.

and fredvx: 27% over EPA (2 tanks).

nothing outright conclusive, but it's good supporting evidence for your theory about epa & "efficient" cars.

[MetroMPG]

Originally Posted by philmcneal

EPA .... using it as a "comparason" factor seems kind of out of place due to the differences in cars.

maybe, as the EPA sometimes says, never mind absolute accuracy, it's a valid way to compare cars in the same class. (i'm pretty sure i've read that 'defense' of the ratings before.)

e.g. it's valid to compare a metro vs a vx, or a regular civic against a regular corolla, but not the vx against the corolla.

[philmcneal]

i was more concerned over the areodynamics since that wasn't a factor for the old epa testing.

[95metro]

Thanks for that chart metroMPG! Totally explains why my fuel average went UP after I STOPPED highway driving. With our 110 km/h speed limits in Alberta (and having to hit 115 to keep from getting run over) that totally explains why I could barely hit a 40 mpg average. I must have been get about 35 mpg on the highway during the winter! Yuck!

PS: I've heard that the Sprint/Firefly Turbos get WAY better highway mileage than the NA clones. Wouldn't mind testing a turbo setup with 1 or 2 pounds of boost for the city and then adjusting it to the stock 7 pounds for highway.

[MetroMPG]

you're welcome. now that your at gassavers, you get an early look at stuff i eventually clean up and post at metrompg.com

i can get away with 95 km/h on the freeway unless i'm getting closer to ottawa or toronto, so i haven't taken as much of a highway hit as you have.

i hadn't heard that the turbos got better mileage. that's very interesting...

[MetroMPG]

FYI - for those who were interested in this thread, I've (finally) posted a summary, with some new cleaned up images, at MetroMPG.com:

• Speed kills: testing MPH vs. MPG in top gear

[SVOboy]

New transmission graaaaaph!

[GasSavers_Jack]

Thanks for the info and the link to the Graph. I was trying to explain that to someone today at lunch for 20 minutes. Got back and showed them the graph. He finally got it then.

[MetroMPG]

If I did a new one today with the new transmission, you couldn't compare it directly to the original, since it was made when the temps were 58 F.

In fact, I realized last night that my claim of 8.x% improvement with the taller transmission is faulty, because I based it on the colder ambient speed/mpg data. The actual transmission improvement is less.

[MetroMPG]

Originally Posted by Jack

showed them the graph. He finally got it then.

worth 1000 words, isn't it! :P