There has been much talk about how many rpm's people are turning at a
given speed. Looking at you speedometer and tachometer will give you
a close estimate, but here is the formula for calculating rpm and speed.
You can also check your speedometer accuracy this way and see what
affect putting bigger tires on your truck will have.
mph=(tire diameter*engine speed)/(tran ratio*axle ratio*336)
tire diameter=inches
engine speed=rpm
*One note- with an automatic without a locking torque converter, torque
converter slip must be taken into account.
For a metric tire the diameter is calculated as follows;
ie:235/75/15R
dia=((width*aspect ratio*2)/25.4)+rim dia
dia=((235*0.75*2)/25.4)+15
dia=28.9inches
Brent Cring
91 V-8 4x4
This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 12:07:25 EDT