optimal rpm for economy

[Dieselvwguy at aol.com]

I have owned many different european cars, gas and diesel, turbo and non 
turbo. Most cars get their best economy around 50-55mph on the highway, any 
slower and your not really driving highway speeds! I can get 40mpg out of 
anything I have owned, ranging from 4000 and 5000 Audi quattros to Volvo 745 
turbos. I find the trick is a constant throttle position, not increasing the 
throttle up slight hills etc. Smooth progessive acceleration (more gas at mid 
rpms not low rpm). I also find turbo cars USE MORE fuel then non turbo cars, 
at light throttle the turbo is more restrictive then beneficial (only under 
light loads, under "normal" driving I would say a turbo car is easier on 
fuel). I only drive on the highway (live far outside of town) on 4 lane 
highways. I deffinately find a diesel is more beneficial when driving slow, 
they seem to make the most of it. I saw 75mpg on a few 1990-92 1.6 diesels 
(non turbo) at 55mph.  I also find CIS gas systems to the best for economy so 
far, especially early Golfs and Jetta (1985-1987)
Greg