Bigger tires can help you crawl up those slick rocks, look cool, and rob you of power. One way to compensate for this is to swap out your differential gears. The left side of the calculator requires all three entries. The right side will show the results. The New Gear box will show the ideal gear ratio (getting as close to stock as possible). If you want a bit more power, for rock crawling, go with something closer to the Lo Gear number. Also, the Effective Ratio box shows your adjusted gear ratio if you choose to keep your original gears.