The DynoMax performance exhaust system for 2015 Ford F-150 3.5L V6/5.0L V8 trucks offers a combination of powerful performance and a smooth, deep tone. The new system improves horsepower by 16 and adds 19 ft.-lbs. of torque. Each cat-back, single exhaust system includes a stainless steel DynoMax Ultra Flo welded muffler. This muffler is a stainless steel, fully welded design that has straight-through internal piping to help provide unrestricted exhaust flow and reduced backpressure. Each Ultra Flo welded muffler includes Continuous Roving Fiberglass (CRF) technology that helps to absorb unwanted interior drone while providing a rich, throaty performance sound. The new stainless steel system (p/n 39508) includes a buffed and polished four-inch outlet, single wall, buffed and polished 12-inch slant cut tip and three-inch mandrel bent, stainless steel piping. The exhaust system fits extended cab short bed and crew cab short bed Ford F-150 models.