Editing Steering (section)

===Power steering===
{{Main|Power steering}}

Power steering helps the driver of a vehicle to steer by directing some of its engine power to assist in swiveling the steered road wheels about their steering axes.  As vehicles have become heavier and switched to [[front-wheel drive]], particularly using negative offset geometry, along with increases in tire width and diameter, the effort needed to turn the wheels about their steering axis has increased, often to the point where major physical exertion would be needed were it not for power assistance.  To alleviate this, auto makers have developed power steering systems, or more correctly power-assisted steering, since on road-going vehicles there has to be a mechanical linkage as a [[fail-safe]]. There are two types of power steering systems: [[Hydraulic power steering|hydraulic]] and electric/electronic. A hydraulic-electric hybrid system is also possible.

A Hydraulic Power Steering (HPS) uses hydraulic pressure supplied by an engine-driven pump to assist the motion of turning the steering wheel. Electric Power Steering (EPS) is more efficient than hydraulic power-steering, since the electric power-steering motor only needs to provide assistance when the steering wheel is turned, whereas the hydraulic pump must run constantly. In EPS, the amount of assistance is easily tunable to the vehicle type, road speed, and driver preference.  An added benefit is the elimination of the environmental hazard posed by leakage and disposal of hydraulic power-steering fluid.  In addition, electrical assistance is not lost when the engine fails or stalls, whereas hydraulic assistance stops working if the engine stops, making the steering doubly heavy as the driver must now turn not only the very heavy steering—without any help—but also the power-assistance system itself.