överdrive

Overdrive is a term used in several technical domains to describe operation beyond a standard or linear range, typically to improve efficiency or alter signal characteristics. In automotive engineering, overdrive refers to a gear ratio in which the output shaft turns faster than the input shaft, resulting in lower engine RPM at a given road speed. This is usually a gear with a ratio below 1:1. The practical effect is reduced engine speed and fuel consumption during highway cruising, along with reduced wear. Many modern transmissions present a top gear that acts as overdrive, and vehicles may offer an overdrive on/off control or a lock-up mechanism to improve efficiency further. Overdrive is most beneficial at steady high speeds but can be less suitable under heavy load or steep grades, when drivers may disengage it to obtain more torque.

In electronics and audio, overdrive describes a form of distortion that occurs when an amplifier is pushed beyond its linear operating range. The resulting clipping is often soft and compressed, producing a warm, mid‑range-heavy tone that is widely used in guitar amplification. Overdrive differs from harsher distortion or fuzz in its smoother onset of clipping and greater retention of dynamics. In pedal effects and tube amplifiers, overdrive can be generated by preamp saturation or specific clipping circuits, and it remains a common sound characteristic in many genres.

Beyond these, the term appears in various industry names and product branding, sometimes used metaphorically to indicate high performance or accelerated response.