An axle back exhaust is common on late-model vehicles that have low ride height and reduced ground clearance. These vehicles typically have the muffler located near the rear of the vehicle, often using the outlet of the muffler as the exhaust tip or tail pipe, albeit a very short one. Fastened to the catalytic converters of these vehicles are long, straight exhaust pipes that run under the vehicle's floor boards, tucked high up into the vehicle's chassis, to eliminate ground clearance issues. The axle back exhaust commonly attaches to this straight pipe at, or slightly behind, the rear axle of the vehicle. The axle back exhaust system usually consists of a short radius bend pipe attaching to the muffler and a short tail pipe.
Often, factory mufflers and exhaust systems are very restrictive. This causes the engine to produce less horsepower as the exhaust gasses are forced to struggle through the restrictive exhaust system to exit the engine. By placing a less restrictive, aftermarket axle back exhaust system on a vehicle, the engine often runs cooler and more power is produced. Another key factor in the decision to install the axle back exhaust is the noticeable exhaust-rumble the system produces. A quality axle back exhaust can not only add increased performance — the systems typically include polished chrome or stainless steel exhaust tips to add visual appeal to the vehicle.
A wide variety of the axle back exhaust systems are very user-friendly, allowing the vehicle's owner to complete the installation in a driveway in a matter of a few hours. The quality of the system is commonly much better than the vehicle's original equipment package. Aftermarket systems commonly use mandrel bends to create a much smoother flow of the gasses, as well as improve and increase the product's lifespan by limiting areas that rust can begin to form on in the smooth bends. Original equipment pipes are typically bent with large pinches and crimps that collect salt and debris, creating areas prone to rust.
Many manufacturers of the axle back exhaust systems offer lifetime guarantees on the products. An anti-seize compound should be placed on the pipes where the original exhaust and the aftermarket units overlap to prevent oxidation and corrosion forming between the two dissimilar metals. Many manufacturers of the axle back systems also recommend the use of only stainless mounting hardware.