Quote:
Originally Posted by Greg
Fascinating! I never would have thought of trying to make my own diesel fuel from canola oil!
Now wait... let me figure this out... a gasoline engine runs at a higher rate of revolution than a diesel engine, so it's geared down more. So if I hooked up a slower-turning diesel engine, I would expect the vehicle to move more slowly... no... that's not it... oh, I'm lost!  |
That is correct. A slower revving engine with the same over-all gear ratios will be considerably slower in the top speed stakes.
Luckily, the diesel engine is much stronger torque wise, so can "pull taller gearing". That is, a closer input to output ratio. Tail or prop shaft to axle RPM ratios. Gear box ratio's, differential gear ratio's.
(I recall an experimental Mercedes, 5 cylinder diesel, high performance prototype from the late 1970's, early 1980's. Clocked at 320+ KPH at Nuremburgring. Tall gearing.)
This, combined with tire rotation distances, give the over-all final drive ratio.
Which by the way, does actually change with tire wear. Worn tires are smaller than new ones and actually travel less distance per rotation.
Minimal, but true.