Parallelhybridi

Parallelhybridi is a type of hybrid propulsion system used in some road vehicles, where both an internal combustion engine (ICE) and an electric motor can contribute to wheel propulsion in parallel. In a parallel hybrid, the engine and motor are connected to the drivetrain so that either or both can drive the wheels, with power sharing controlled by an electronic control unit. The vehicle stores energy in a battery, which is charged by the ICE via a generator or by regenerative braking when the vehicle decelerates.

Design variations include mild parallel hybrids, which primarily use the electric motor to assist the engine and cannot drive the car on electric power alone, and full or strong parallel hybrids, which can propel the vehicle using the electric motor for short distances or at low speeds. Common architectures use a clutch or a gearing arrangement to couple the motor and engine to the drivetrain; some designs employ a fixed mechanical connection, while others use a gearing set that allows some degree of power splitting.

Advantages of parallel hybrids include improved fuel economy, smoother start-stop operation, and energy recovery through regenerative braking. Limitations include increased mechanical complexity, higher cost, and packaging challenges compared with conventional powertrains. Parallel hybrids have been widely used in passenger cars since the late 1990s; notable early examples include Honda's Integrated Motor Assist designs, with many later models from various manufacturers adopting parallel-dominant or mixed configurations.

See also: Series hybrid, plug-in hybrid, mild hybrid, full hybrid.