Originally Posted by rch10007

Thanks all for the replies! I'm going to look into serious offroad.

PT - that chart is very misleading. I appreciate that you are helping me but that chart does not account for final drive ratios. You have tire size vs. gear ratio AT a given RPM given a certain drive ratio which is not specified for that chart. It is not accurate for stock 28" tires with a 3.07 that isn't even on that chart. In fact, it says I should be using a 3.73 right now and that is just not true. I would have extremely high rpms at cruising speed and my fuel mileage would go to ****. There are many better calculators out there that will show what gears to select given an increase in tire size. Again, I sincerely appreciate the help but the chart you show is not accurate for our XJ's.

Originally Posted by no rdplz

Yeah, definitely the wrong chart there. With the ax-15 and 35's you want 4.10's-4.56's to be close to the factory final drive ratio (4.10's for better mpg's, 4.56's for better low-end torque).