DriverSide's Car Dictionary has the most comprehensive definitions of automotive terms. This auto glossary can help you decipher what your mechanic is fixing and what the purpose or function of the particular auto part or accessory is for. We have taken the mystery out of automotive service jargon, so that you don't have to.
An abbreviation for 'Top Dead Center'. This is the point in the piston's stroke at which the air/fuel mixture is maximally compressed. Ignition should occur at TDC.