A tailpipe is the tube at the back end of a car or truck where exhaust gases come out after the engine burns fuel. When you see a vehicle driving down the road, the tailpipe is usually that metal pipe sticking out from underneath the rear bumper, sometimes releasing a little puff of vapor, especially on cold days.

Inside an engine, burning gasoline or diesel creates hot gases that need to escape. These gases travel through the exhaust system and finally exit through the tailpipe. On a cold morning, you might notice white vapor coming from a tailpipe: that's mostly water vapor from the combustion process meeting cold air.

The tailpipe is the last part of a vehicle's exhaust system, which also includes the muffler (which quiets engine noise) and the catalytic converter (which cleans some of the harmful chemicals from the exhaust). Before environmental regulations, tailpipes released much more pollution directly into the air. Modern cars have cleaner exhaust systems, and electric vehicles don't have tailpipes at all since they don't burn fuel.

When someone says they're following too closely behind another car, they might joke about being “right on their tailpipe,” meaning dangerously close to the rear of the vehicle ahead.