Cory Dunkle a écrit :
> Driving at 85 MPH vs 70 MPH only reduced my mileage by .3 MPG. So take that
> you speed kills freaks and tree huggers. Anyhow...
>
> This is in my '68 Galaxie 500 with a 302, FMX, and 2.80:1 gears. The reason
> I believe it made no significant difference is because my engine has a lower
> BSFC at 3000 RPM (85 MPH) than at 2400 RPM (70 MPH), so the increased drag
> from the air is compensated for by greater fuel efficiency at that RPM. My
> engine should have the least BSFC in the 3000-3500 RPM range. Get out of
> that range, up or down and efficiency decreases.
>
> It it's of any interest the mileage was 14.5 at 70 MPH and 14.2 at 85 MPH. I
> expect to gain another MPG or two when I get my timing dialed in just where
> the engine wants it. Right now I've only got 30* total mechanical in by 3500
> RPM or so plus whatever vacuum it takes while cruising. I'm gonna give it a
> few more degrees machanical and hae it come in by 2500-3000. Trick is to get
> the curve just right so it doesn't ping on 93 octane and I can still have a
> dencet amount of initial advance (10* now). Come spring I'll have new heads
> though and I'll be able to run on 87 or 89 with as much timing as the engine
> wants. No more of this 11:1 crap. That and an electric fan which should get
> me another MPG or two on top of wahtever I get from getting my timing
> straightened out.
>
> Anyhow, if anyone else has calculated their mileage at different speeds I'd
> be interested to know what it is at the different speeds and what type of
> car it is.
>
> Cory
>
>

Well...

I was getting something like 30mpg once at 100km/h steady (62 1/2 mi/h)
in a Saab 900 turbo 16.

And then I got her up to 150km/h (95mi/h) and calculated to something
like 26. The milage goes up on this car up to around 100, and then to
150 it goes down slightly - but at a solid 200km/h it drinks something
like 18 mpg!!

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