back to centre position. The amount of pressure applied is proportional to road speed, so that at low speeds the steering is very light, and at high speeds it is very difficult to move more than a small amount off centre. It was invented by Citroën of France. As long as there is pressure in the car's hydraulic system, there is no mechanical connection between the steering wheel and the roadwheels. This system was first introduced in the Citroën SM in 1970, and was known as 'VariPower' in the UK and 'SpeedFeel' in the U.S. Electro-hydraulic systems Electro-hydraulic power steering systems, sometimes abbreviated EHPS, and also sometimes called "hybrid" systems, use the same hydraulic assist technology as standard systems, but the hydraulic pressure comes from a pump driven by an electric motor instead of a drive belt at the engine. In 1965, Ford experimented with a fleet of "wrist-twist instant steering" equipped Mercury Park Lanes that replaced the conventional large steering wheel with two rings, a fast 15:1 gear ratio, and an electric hydraulic pump in case the engine stalled. In 1988, the Subaru XT6 was fitted with a unique Cybrid adaptive electro-hydraulic steering system that changed the level of assistance based on the vehicle's speed. In 1990, Toyota introduced its second-generation MR2 with electro-hydraulic power steering. This avoided running hydraulic lines from the engine (which was behind the driver in the MR2) up to the steering rack. In 1994 Volkswagen produced the Golf Mk3 Ecomatic, with an electric pump. This meant that the power steering would still operate while the engine was stopped by the computer to save fuel. Electro-hydraulic systems can be found in some cars by Ford, Volkswagen, Audi, Peugeot, Citroën, SEAT, Škoda, Suzuki, Opel, MINI, Toyota, Honda, and Mazda. Electric systems Electric power steering (EPS) or motor-driven power steering (MDPS) uses an electric motor instead of a hydraulic system to assist the driver of the vehicle. Sensors detect the position and torque exerted inside the steering column, and a computer module applies assistive torque via the motor, which connects either to the steering gear or steering column. This allows varied amounts of assistance to be applied depending on driving conditions. Engineers can therefore tailor steering-gear response to variable-rate and variable-damping suspension systems, optimizing ride, handling, and steering for each vehicle. This new technological feature also gave engineers the ability to add new driver assistance features. This