Going to be getting gears this week and was curious as to how much rpm's increased/raised with either 4.10's or 4.56 gears installed? Thanks



2003 Ram Hemi

 

Not really that much at all, it's over played by those who have not had them done. It's actually about 300 rpm at a given speed when I went from my stock 3.92's to my current 4.56's.

 

At 68MPH on the freeway with 33" BFG ATs and 4.56 gears, I sit right at 2,100 RPM.

 

SO if you went from 3.92 to 4.56 and saw a gain of 300 rpm's, then I should see about 500 with going from 3.55 to 4.56's.... thanks

 

Here, try this calculator:

http://offroaders.com/tech/mph-crawl-ratio.htm

 

it is always best & less confusing
to find the MPH in each gear for each 1000 rpm of the engine.

This MPH/1000 rpm number

for 2nd gear tells you how well the truck will accelerate
with the lower the number the better
and ideally 60 mph would be just a bit over engine redline rpm

and for top overdrive gear the MPH/1000 needs to be at least
40 or so for good highway cruise MPG

MPH/1000 rpm
takes into account tires, trans and differential
it is the 'solid' number that you can depend on