All aFe Diesel Exhaust Systems are 4", aluminized, mandrel bent and aluminum welded, giving you the maximum flow available! aFe 4" Diesel Exhaust Systems require absolutely no welding to install.

One of the greatest benefit of an aFe 4" Diesel Exhaust System is a reduction of exhaust gas temperatures, or EGT's. An aFe 4" Diesel Exhaust System can reduce EGT's by as much as 100° or more. A cooler turbo provides prolonged turbo life, fuel economy is improved, and turbo spool-up time is reduced.

Horsepower and torque increases of up to ten-percent can be expected. To achieve even greater horsepower and torque increases combine an aFe 4" Diesel Exhaust System with an aFe Magnum Force Air Intake System, Edge Module, and Superchips MAX MicroTuner!