Re: Formula for speed

[Mark Sirota <msirota@isc.upenn.edu>]

jon e prevo wrote:
> Does anyone have a formula for calculating vehicle speed using engine
> rpm, trans ratio, diff ratio and tire dia?

engine speed * trans ratio * diff ratio * tire circumference.

Adjust for unit conversion (if tire circumference is in inches and
engine speed is in RPM, you'll wind up with inches/minute).

Obviously, you'll need to be careful of the direction of your gear
ratio calculations.

Mark