Right now I have a stock unlimited auto with 3.73 gears and the stock 255/75/17 SRA tires. I would like to go with 285/70/17 duratracs. about how much power and mpg's can i expect to lose? we have mostly flat roads with a few decent hills here and there. I do tow a trailer with my 700lb. atv on it, but that is about the heaviest towing I do. I am not looking at a regear any time soon. Or, would I be better off sticking with 265/70/17 duratracs? thanks

 

The clearest way to judge this, for me, is. Do you like the way your rig tows right now? Or could you use a little more power? I'm running the 4.10 with the tow package w/ 245/75r16 Duratracks. I wanted to go with the 265's real bad. But I could not stand the sacrifice.

 

Hi! I run 285/70R-17D and avg. 15mpg but...I also have 4.88's. Before I regeared I was getting solid 17mpg avg. w/ 3.73. Hope this helps.

 

Before I threw on the 315's I was averaging 19-20 mpg. Now, I average 17-18 mpg. I also have the superchips, drive easy, and shift at 2.5... hope this helps

 

Turn OD Off and you will be fine.

In the Drivetrain FAQ's, there is a good rpm chart. Do a quick search to find the actual height of those new tires mounted and on the vehicle, then plug it into the chart. That will give you the OD On rpm. Divide that number by .69 to get your OD Off. You are shooting for mid 2k's.