Tire size & gears

[DGamelin]

Does anybody know what the out side diameter of the stock tires are for a 235/80R17 dullys?

Has anyone put a overdrive unit (us-gear) on a 3rd generation? If so what gear ratio & trans did you have? Did you see a MPG improvement? Looking to buy a new truck.





93 250 216K STOCK

 

[klenger]

According to the Excel worksheet on my website at http://www.klenger.net/dodge/general-reference/gear-speed-calculator.xls, the diameter is 31. 8". You can mess with the numbers using this worksheet to calculate RPM and vehicle speeds depending on transmission type and axle ratio.

 

[SRadke]

Most tire manufacturers will give you a "revs per mile" number for their tires.