tailpipe
An exhaust pipe exhausting to the aft of the vehicle.
tailpipe: the final exhaust outlet at the vehicle's rear
The tailpipe is the rearmost section of the exhaust system, typically a 2 to 3 inch diameter steel or aluminized steel tube that directs hot exhaust gases from the muffler to the open air behind the vehicle. It is the visible pipe at the rear bumper, and often the only exhaust component a casual observer sees.
Tailpipes vary by vehicle class and emission standard. Passenger cars often have a single tailpipe, while performance vehicles and trucks may have dual outlets, sometimes staggered or angled outward. Diameter, wall thickness, and outlet design affect backpressure and acoustic signature. Premium vehicles may use polished stainless steel; commercial vehicles typically use raw or painted carbon steel that corrodes over time, which is why rust-through at the tailpipe is a common wear point.
Function and location in the exhaust system
The tailpipe sits downstream of the muffler and resonator. Its job is simple but critical: route gases safely away from the vehicle body and occupants without leaks. Exit velocity matters; a tailpipe that is too small creates backpressure that reduces engine efficiency, while one that is oversized can cause low exit velocity and odor issues. The pipe is usually mounted on rubber hangers to isolate vibration from the chassis.
Tailpipe condition is a frequent failure point in vehicle inspections because it corrodes from the inside due to moisture and acidic condensates in exhaust gas, and from the outside due to road salt, water spray, and road debris. A hole or perforation triggers failure of emissions and noise tests. The tailpipe is also the point of measurement for emissions testing, as analyzers sample gas directly at or near the outlet.
The term 'tailpipe' is older North American usage; British automotive English often says 'exhaust pipe' or 'exhaust outlet'. Custom and aftermarket tailpipes are common modifications, used both to alter visual appearance and to reduce exhaust restriction on tuned engines. However, jurisdictions regulate tailpipe diameter, material, and noise output to control vehicle emissions and noise pollution.