What does 'AT' stand for in automotive context?

In automotive context, “AT” stands for automatic transmission.

An automatic transmission changes gear ratios without requiring the driver to manually select each gear or operate a clutch pedal. Traditional automatics use a torque converter to transfer engine power and allow the vehicle to remain in gear while stopped. Hydraulic circuits and electronic controls choose shift points based on speed, throttle position, load, and other inputs.

The abbreviation appears in vehicle specifications, repair manuals, dashboard indicators, and model names. “AT” is often used as a general label for an automatic gearbox, even though modern automatic vehicles may use different designs, including continuously variable transmissions (CVTs), automated manuals, or dual-clutch transmissions.

The first mass-produced fully automatic transmission was Oldsmobile’s Hydra-Matic, introduced for the 1940 model year. That milestone helped make two-pedal driving practical for ordinary motorists. “AT” should not be confused with “AMT,” which usually means automated manual transmission, or “DCT,” meaning dual-clutch transmission.