BMW M3: "The optimal speed for fuel economy in this car seems to be around 80mph"

[MetroMPG]

Anybody with an M3 want to bust/confirm this guy's "tip"?

Since this seems to be coming up a lot more recently, I thought I'd post it and some fuel efficiency tips.

The optimal speed for fuel economy in this car seems to be around 80mph.

While you have to give him credit for laying out out his testing approach (details are posted in an M3 enthusiasts forum, see link below), the absense of 50 & 60 mph speeds seems to me to be a gaping hole in the data.

I'm pretty skeptical of the conclusion.

Forum thread: http://www.m3forum.net/m3forum/showthread.php?t=216328

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FYI, as a point of comparison, I tested the fuel economy of a 505 hp Corvette, and its best economy landed pretty much where I expected it would: (meaning, nowhere near 80 mph)

http://ecomodder.com/forum/showthrea...05-a-9841.html

[metroschultz]

I must confess, I would have thought he would attain better mileage ~ 50 - 55. Or right after he goes into overdrive and torque lock. But who am I? I'm trying to get 50 mpg out of a car with 199K on the clock that is in desperate need of a rebuild.
S.

[MetroMPG]

The M3's engine is a high performance monster, which is why I said "skeptical" rather than jumping up and down yelling "baloney!"

But still, he's basing his conclusion on the 80 mph figure being better than the single 70 mph point.

[SVOboy]

Is it a six speed?

[RH77]

If you look at the "There/Back" portion of the 80 mph data set, the "Back" is significantly larger, statistically. As we know, one round-trip test generally doesn't cut it.

50 and 60 mph is indeed missing. But (GASP!) You can't drive an M3 that slow!

RH77

[SVOboy]

I find this tip curious: "gears mean your using more fuel at any speed"

The test course was only a totaly of 6 miles, with a turn around as well.

[meemooer]

the back portion must have been down hill, and either way, the guy is ridiculous for trying that high of a speed

[diesel_john]

that must be 80 kilometers, the data would almost make sense then.

[rocket]

different engines are more efficient at different speeds, then tie that in w/ gearing and the cars areodynamics, i can see how 80mph could be the best speed for MPGs. I used to drive a 91 Camero RS V-6 and consistantly made 30mpg at 80mph, occasionaly 32mpg.

[MetroMPG]

Which is why I didn't yell "baloney!" right off the bat. Still, I'm doubtful its the best speed for max mpg.

I take it nobody has an M3 at their disposal to confirm/bust this one I've seen a new one tooling around town lately, but I have no idea who owns it.