95 Geo Prizm Final Drive ratio
 

Does anyone know the final drive ratio for the 1995 Geo Prizm , 1.6L engine, 3 speed automatic with lock up converter. ? Trying to figure out tire rpms. Do tires increase in radius due to centrifugal force at highway speeds? If I measure the radius of the wheel/tire at standstill, will that be accurate for highway speeds?

3.53

http://www.automobile-catalog.com/

Can't post direct link for some reason, good site to stick in your favorites.

If you have tires listed on tirerack or similar sites the often list the rev's per mile.

I wonder if the revs per mile they quote is based on the radius of the tire just sitting there, mathematically calculated based on tire dimensions, or does it represent the actual loaded radius of the tire with the car weight on it?

I don't believe the circumference will significantly increase due to centrifugal force, considering the steel belts, but Capriracer would probably be a great resource for this question.

The best way to measure circumference is to mount the tires, bring them up to operating temperature and pressure, and measure the distance the tire travels in one or more rotations. Centrifugal force will be insignificant compared to the weight of the vehicle compressing the tire.

Thank you! I've been looking for this for the new cars, but didn't find it. Exactly what I was looking for.