When you change your tire size you need to make sure you have the right gearing to get optimal fuel economy and power. A good way to calculate this is to mutiply .12 by your Jeeps tire diameter (Example: .12 X 38" = 4.56). Here at Omix we have a made an easy to read chart for you to get a good estimation on the best gearing for your Jeep. The three distinct colors below can help you decide what is the right gearing for you...

• Green = Best MPG, this is what you would want to get for the best fuel economy and highway cruising.
• Brown = Best Overall, this is good mix of power/MPG and considered best for daily driving.
• Orange = Best Power, this will give you the best performance for towing power, but at the cost MPG.

These calculations are assuming a manual transmission at 65 MPH with a gear ratio of 1:1. If you drive an automatic your RPMs will be slightly higher,and if you have overdrive your RPMs will be slightly lower.