A zero-turn riding lawn mower (colloquially, a z-turn or zero turn) is a standard riding lawn mower with a turning radius that is effectively zero when the two drive wheels rotate in opposite direction, like a tank turning in place.
Different brands and models achieve this in different ways, with hydraulic speed control of each drive wheel being the most common method when a gasoline or diesel engine is used. Battery-powered models simply use two electric motors. Both commercial duty and homeowner models exist, with varying engine power options, size of cutting decks, and prices. A z-turn mower typically drives faster and costs more than a similarly sized conventional riding mower that has steerable front wheels.