Tenneco Automotive is describing the new Walker NoiseBreaker as the trucking industry's first low-cost, high efficiency muffler engineered to silence heavy-duty vehicle exhaust and engine brake noise while increasing engine efficiency. The muffler combines industry-best acoustical performance with an innovative ultra-high-flow design that reduces system backpressure by as much as 60%. Under engine braked deceleration, the NoiseBreaker is 2 to 4 dB quieter than the industry's best OE mufflers, according to Tenneco.