Does anyone have...........

[shakemyhand]

Does anyone have a list of how many RPM's per MPH for 4:10, 4:30, and 4:56 gear sets.

[gmac]

Will get you some exact readings when I have the R out on the next day or so, but as a rule my RPM went up about 225 when I upgraded from the stock gears (auto - 2005) Gas mileage difference has been neglible, hard to say though since I also had a Wester's tune done at the same time. MPG seems to be almost identical (barring the lead foot of course)...

[Doug Allen]

Do a search, there are several old threads that cover this subject.

Gear Ratio Charts

[hdflstf]

Easy math (close but not exact):
4.10 is 10% higher RPM
4:30 is 15% higher RPM
4.56 is 20% higher RPM

[Topspin]

Here's a formula that I've used, for ever, that has proved quite accurate.

RPM x tire diameter (in inches) x 2.96 divided by rear end ratio x 1000 = MPH.

Now for the rear ratio portion, just multiply times whatever trans, gear that you want to compute. For the auto. trans. it's 3.06, 1.62, 1, .70. You're probably mostly interested in cruise rpm in high gear, so with the stock 3.73 x .7 you'll end up with a final drive ratio of 2.61. So, trying 2000 rpm with stock gears and tires, it would look like this.

2000 x 29.3 x 2.96 = 173,456. Divided by 2.61 x 1000 = 2610, for 66.46 MPH.

I play around with this a lot, before making any drivetrain change.