Performance exhaust systems are available in multiple sizes. The most common is a four-inch, which is designed for vehicles creating less then 450 horsepower. Larger diameter exhaust systems, such as five-inch, are typically recommended for vehicles creating greater than 450 horsepower. Performance exhaust systems increase exhaust flow by eliminating the restrictive stock muffler, replacing factory crimped bends with smooth mandrel bent tubing and increasing the overall pipe diameter. The benefits of increased exhaust-flow are reduced exhaust gas temperatures, increased horsepower and torque, fuel mileage gains and a deep throaty sound. With a large network of well-respected brands to choose from, such as AFE Power, Banks Power, Gibson Exhaust, Magnaflow Performance Exhaust and MBRP Inc., you can select the exhaust system that looks right to you without any concerns about its quality.