MOJO1

Got a question my 6sd runs 2k at 65 mph 2.3k at 70 mph.Dose that sound about right? Seems to be high to me. My auto has 410s & 315 tachs lower.(Help me understand this) Thanks

ptm600

That sounds about right to me yours should be a little higher rpm than mine being you have the g56 6 speed. Mine is at 2k at 68 mph. The auto tranny has a lower ratio producing lower rpm. Your 315 tires are really what get the r's down on the auto though.

MOJO1

So the only way to get the rpms down is to do a gear swap or bigger tires?
I realy dont want to do a gear swap but dont wnt to lift the truck eather. I guess im doing one or the other. Trying for better fuel milge.

nitis

have you calculated that you are about 10% off on your speed so your speedo reads 65 but you are really doing 71 I have 315 70 17 so yours are slightly taller than mine and I figured this out going accross idaho I knew I was off but that made me feel better.

MOJO1

I took mine to the dealer he programed it as close as possible im about 2 over.

dodgezilla04

you could put a gear vendors overdrive on it. kinda like an aux. trans. $spendy though$