Changing tire size is one of the first mods any 4x4'r does to his/her rig. Did you know larger tires reduces your gear ratio? This means less power, inaccurate speedometer, among other performance hits. The "right" way to add larger tires is to also add lower gears (gear ratio) to counteract the larger tires. This calculator will give you suggestions on what that new gear ratio should be for more torque and better gas mileage. Check out our other calculators too. Ever curious of what your 4x4 articulation ramp score would be, but never had access to a ramp? We have a calculator for that! Among others, give it a download and let me know what you think? --Mark