How hydraulic and electric power steering work, what maintenance they need and which vehicle types each suits best.
An MSG Equipment article explains the two types of power steering. In a hydraulic system, a belt-driven pump sends fluid through a distributor to the relevant side of the rack cylinder when the wheel is turned. During parking the pump works at full capacity, so holding the wheel at full lock for long periods shortens its life.
Electric power steering (EPS) has no belt or hydraulics; an electric motor controlled by sensor data provides assistance, acting either on the rack or on the steering shaft.
- Hydraulic: inexpensive and relatively easy to repair, but bulky, and fluid and belt must be replaced regularly
- EPS: draws no engine power, needs little maintenance, responds quickly and saves space
The article concludes that EPS suits passenger cars and crossovers, while hydraulic steering remains common in off-road and commercial vehicles.