How Do You Calculate Gear Ratios For Bigger Tires?
If you have recently upgraded your truck tire size, your truck’s gas mileage and power can be adversely affected, and the speedometer will read incorrectly. Re-gearing the axles can trick the truck into thinking that there have been no tire modifications at all, effectively restoring your mileage and speedometer back to normal. Here’s how you can calculate the gear rations for bigger tires. Measure the old tire size, in inches, with a tape measure. Also measure the new tire size, in inches, and write both numbers down. Divide the new tire size by the old tire size, and write that number down. Multiply that number by your current gear ratio. To calculate your current gear ratio, jack the rear of the vehicle up and spin the driveshaft exactly one revolution. Count how many times the wheel turned completely around per one turn of the driveshaft. If you come up with 3.5, then your current ratio is going to be about 3.5:1. This final number is your optimum gear ratio. Chances are that the e
