Many muffler manufacturers advertise, test and rate the performance of their mufflers with the use of a flowbench. The problem with this methodology is that a flowbench produces a steady, low temperature stream of air and lacks the acoustical and thermal dynamics that are produced by an internal combustion engine. Flowmaster designs, tests, and proves it's products under real world conditions in the dyno cell, at the track and on the road. After all, when was the last time you raced a flowbench?