When changing tires or gearing, a driveline calculator is invaluable for making informed choices.  On one hand, oversized tires can make a vehicle feel underpowered.  Changing the gearing for more power can cause the engine to race at freeway speeds.  With a driveline calculator, simply enter the many variables such as tire size and gear ratios and compute what works best for you.

The Vernco Driveline Calculator