What tire size to get 3.73 ratio from 4.10s?

[Motorhead]

A friend of mine traded his '97 in and bought an '02 ISB 4x4 with 4. 10s. His old rig had 3. 54s with the auto trans. and he thought that he might want to tow with the new one. I suggested that He go with the 4. 10 gears with the auto. Well, He thinks that the final ratio is too low for highway driving at speeds. He as well as myself would of liked to see a 3. 73 offered but DC doesn't listen to us. Anyhow, i suggested the 19" tire and wheel route(Why do I get myself into these things?) as the cheapest way to get around 3. 73 ratio on a 4x4. What is the formula to figure what tire height to use with a 4. 10 ratio to achieve approx 3. 73 ratio? Chris

 

[HEMI®Dart]

You should be able for figure it out here:



http://www.dodgeram.org/tech/specs/axle/rpm_vs_mph.htm

 

[B KIRK]

Or here also



http://www.4wheelparts.com/Tirel_Gear_Ratio.asp



Brad

 

[milehiscott]

This one has several active calculators instead of a chart.



http://www.randysringandpinion.com/calculators.html[/URL]



Scott

 

[kchristopher]

255/85-16, but I hear they won't fit on a 2wd. What's your friend have?

 

[Motorhead]

kchristopher and all that replied, I forgot to say that the truck is not a dually. Chris

 

[Chipstien]

I have around a 3. 69 gear ratio with 315's. They might fit on a 2wd.

 

[kchristopher]

Originally posted by Motorhead

kchristopher and all that replied, I forgot to say that the truck is not a dually. Chris

Then it would seem that 255/85-16 would work perfectly.