There is a lot more to an exhaust system then a muffler and some piping. Auto manufacturers spend millions of dollars in research and development to perfect each aspect of the cars that they produce. Designing the factory exhaust system is a significant part of the R&D involved in developing a vehicle. In fact it is just as important, if not more important, than the air induction system.
Today car manufacturers have taken a completely different outlook on exhaust system design compared to 30-40 years ago. In the muscle car era, there were no emissions requirements, and most cars came equipped with large, noisy V8’s. Now days everyone wants the quiet, fuel efficient and environmentally friendly cars that have no soul. As a result, car manufacturers must design vehicles around today’s standards.
Mufflers & Resonators
On most modern vehicles, the most restrictive part of the factory exhaust system lies in the mufflers and the resonators. Mufflers and resonators are essentially canisters that are strategically placed throughout the exhaust system, to keep noise levels down inside and outside of the car. Mufflers and resonators have varying amounts of chambers and insulation inside of them to help cancel out the sound waves produced by the engine through destructive interference. Your average car is equipped with at least one large muffler, and one resonator; most cars have more than one of each.