GEAR VENDORS provides overdrive product to racing cars and trucks up to 2000hp and trucks towing heavy RV's up to 25,000lbs gcvw. Whether you are trying to move a couple tons up a steep incline or moving just a couple thousand down the track — the fastest way is with the right gearing. Add the benefits of a final overdrive ratio to reduce engine rpm and increase fuel mileage by typically 20-28% and you have a product that is the single biggest innovation you can bolt to your car or truck. With fuel costs high the overdrive can pay for itself in mileage and engine wear reductions. That makes the driving pleasure of overdrive, and performance improvements free — and then the vehicle is also worth more when/if you ever sell it with the GEAR VENDORS. In the long run it just doesn't cost you anything to own a GEAR VENDORS UNDER/OVERDRIVE™.