[Diy_efi] Is E85 worth it? Speed factor?

[Jim Kyser]

I would expect that it is lower than 55 for most larger vehicles. 
Somewhere in high gear where the engine can move the car without 
lugging. I would guess more like 45 for many vehicles. The reason I 
suspect it's lower than 55 is wind resistance. It increases as a square 
of speed, so it increases pretty quickly as speed goes up, especially on 
vehicles with large frontal areas.

Jim Kyser

Joseph Obernberger wrote:
> Up to a point - I mean, you certainly don't get the best gas mileage at 
> 0 MPH!  There is some speed where a vehicle (probably different for 
> every vehicle) gets the best gas mileage.  I would at least expect it to 
> be in the top gear, and probably at a speed where the throttle is open 
> enough to minimize pumping loss, and at the same time maintain closed 
> loop operation.
> Somehow I doubt it's 55MPH - probably significantly faster for most 
> modern cars.  The whole idea of reducing the speed limit to increase 
> fuel economy is bogus.
> 
> Joe
> http://www.lovehorsepower.com