Ultimate RV Power System. Everything needed for dramatic power gains. Pass, merge, and climb effortlessly. Adds up to +70 hp and +92 lb-ft (rear wheel), optimizes mileage and durability. The Banks Monster Exhaust is engineered using computational fluid dynamics (CFD) software then tested on both dyno and on-road. Reducing backpressure allows the engine to expel spent gasses with less effort. Less pumping loss means more horsepower, lower exhaust exit temps, and improved fuel economy. The Monster Exhaust system cools while flowing up to 80 percent better than stock! Cooling without killing flow is a major challenge. But the Monster Exhaust wins on both counts thanks to its mandrel-bent constant-diameter tubing and huge Ob-Round patented SideKick tip. The tip is the key. Its unique shape mixes hot exhaust gas with cool ambient air. And, it keeps your trailer safe by directing exhaust gasses to the side. Key Features: Mandrel bent Stainless Steel construction, Virtually eliminates backpressure, Lowers exhaust exit temps, Dramatically improves flow, Maximum Airflow, 4-inch constant-diameter DPF-back, Improves flow up to 50 percent, Cuts back pressure up to 40 percent, Safely clears the spare tire, shocks and brake lines, CHROME tip. US Patent #5,581,111 S1