Exhaust flow out of your engine is just as important as airflow coming into your engine. Therefore, Injen has designed its Injen Exhaust Systems to maximize that outward flow of exhaust gases to keep your engine running at peak performance. These exhaust systems are made from 304 stainless steel, which is durable yet lightweight because Injen understand the importance of keeping your vehicle as light as possible. Furthermore, all the tubing in Injen Exhaust Systems is designed to be as open and as free flowing as possible to get those exhaust gases away from your engine and out of your vehicle as quickly and as effectively as possible so back pressure does not build up. Each Injen Exhaust System is made in the United States and undergoes a rigorous dyno testing to ensure its effectiveness. Because Injen is still a smaller company and because it focuses a great deal of time perfecting its exhaust systems, these systems only fit about a dozen vehicles. However, Injen does sell a universally applicable muffler that is engineered to the same standards as its exhaust systems and also is designed to severely curtail back pressure, which will hamper performance. All customers should definitely get tremendous sales help when purchasing reliable auto parts for their car or truck. To support that need, we created an always-open technical assistance call bureau to address your questions. Everybody hates to pay for shipping, that's why you get totally free shipping for every order $50 or higher. If you find a better price, let us know - we will beat any advertised price for auto parts.