TnT Performance & Repair carries auxiliary transmissions designed to increase torque and fuel economy. Sometimes these units are referred to as gear-splitters. The systems are available in both underdrive and overdrive configurations, depending upon your needs. If you need power to get things moving or the engine lugs at low speed, you need an underdrive system. If you're in search of lower RPM at highway speed, which results in better fuel economy, you want to order an overdrive unit.
