Hey guys just as the title says what are the rpms at 80 mph with 4.56 and 315/75/16 tires and what are rpms at 60 mph with over dirve off. Ive played around with calcs and they jsut dont seem right 2 me so trying to gt real world exp

 

been wondering this myself.

johnny.

 

me to i getting ready to lift and do gears

 

Remember the OD ratio is 0.69 to 1, not 1 to 1. A 1 to 1 ratio only takes into account 3rd gear, which you should have passed by the time you get to 80 mph.

 

Will im wondering what it is with OD at 80

 

Stock

With 265 75 16 OR 31.65

RPM MPH R&P Ratio

1820.29 70 with 3.55
2010.01 70 with 3.92
2010.01 70 with 4.10
2338.18 70 with 4.56
2502.26 70 with 4.88


With 35s

RPM MPH R&P Ratio

1646.06 70 with 3.55
1817.63 70 with 3.92
1901.09 70 with 4.10
2114.38 70 with 4.56
2262.76 70 with 4.88


As for the guys with 305 75 16 your RPMs would be 2486.78 @ 80 MPH. I did all these calculations at http://www.jawsgear.com/calc_rpm.html with OD gear .69

 

I can't say what my rpm's are at 80, never paid any attention, and I don't really drive 80 that often. But at 60, I run 1950 in OD, 3000 with OD off. This is with 35x12.50/17's (about the same as a 315) and 4.56.