I found a Tire/RPM/Ratio Chart (http://www.jeepfan.com/tech/tirerpmratio.htm) and according to the formula on that site:
60 mph + 5.38 gears + 35" tires = 3098 rpm
60 mph + 4.30 gears + 33" tires = 2627 rpm
60 mph + 4.30 gears + 29.6" tires = 2929 rpm (stock)
70 mph + 5.38 gears + 35" tires = 3615 rpm
70 mph + 4.30 gears + 33" tires = 3065 rpm
70 mph + 4.30 gears + 29.6" tires = 3417 rpm (stock)
You are right though 5.38 gears with a 33" or smaller tire would be crazy!
60 mph + 5.38 gears + 33" tires = 3286 rpm
70 mph + 5.38 gears + 33" tires = 3834 rpm
I know this is a Jeep site so for the VX this formula may be a little different, but it does not look like it mentions anything in the formula that is Jeep specific, anyone know if their formula is correct for the VX:
[(MPH x Drive Ratio)/Tire Diameter] x 336 = RPM of the VX?
Also found this one: http://www.4lo.com/calc/geartable.htm and this looks like the best one: http://www.4lo.com/calc/gearratio.htm
But it looks like we need our transmission ratio and our transfer case ratio to make the formula complete, hmm wonder what those numbers are.....
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