What’s hot in exhaust performance products? Bolt-on free-flowing exhaust systems for diesel trucks, big bore mufflers for sport compact cars, and low restriction street performance mufflers for cars like Mustangs, Pontiac G8s, Dodge Chargers and Chevy Corvettes.

The diesel market has been really hot lately. Turbo diesel engines are a popular option in full-size Dodge, Ford and GM pickups because a diesel engine provides gobs of torque while squeezing maximum fuel economy out of each drop of fuel. What’s more, many diesel-powered pickup trucks are used for towing trailers, not just commuting or getting groceries, so any upgrade that adds horsepower is a plus.

The aftermarket has really stepped up to the plate in developing new performance products for diesel trucks. There’s been a proliferation of diesel “tuner” scan tools that allow a user to dial-in more power by turning up the turbo boost pressure and tweaking the fuel mixture and other settings. Also available are a number of bolt-on exhaust performance packages specifically designed for popular truck models. These package systems that typically replace the stock exhaust system from the converter back reduce backpressure and really help the turbo breathe.

The diesel performance market has been stimulated by a growing interest in diesel racing. Truck pulling events have been around for years, and some say interest in this pa...