Rear-wheel steering (also called four-wheel steering) turns a car’s rear wheels slightly as well as the fronts. At low speeds, the rear wheels turn opposite to the front wheels, shrinking the turning circle so a long car maneuvers like a smaller one. At higher speeds, they turn in the same direction, making lane changes more stable. The Mercedes-Benz S-Class can turn its rear wheels up to 10 degrees, cutting its turning circle by roughly two meters — a real advantage on narrow Manhattan streets and tight hotel driveways.

How it works

Speed Rear wheels Effect
Low (parking, city) Opposite to the fronts Tighter turning circle
High (highway) Same direction as the fronts Smoother, more stable lane changes

An electric actuator at the rear axle adjusts the rear wheels based on steering angle and speed. The system is computer-controlled and almost imperceptible to passengers.

A short history

Japanese manufacturers pioneered four-wheel steering in the 1980s, with systems from Honda, Nissan and Mazda. Some were mechanical, others electronic. The technology faded in the 1990s due to cost and complexity, then returned in the 2010s on luxury and performance cars as electric actuators improved.

Where you find it today

  • Mercedes-Benz S-Class and EQS — up to 10 degrees. Read the W223 S-Class.
  • BMW 7 Series (Integral Active Steering).
  • Porsche, Rolls-Royce and Lamborghini models.
  • GMC Hummer EV and Cadillac Escalade IQ, including diagonal “crab” driving.

Why it matters for chauffeured cars

Long-wheelbase sedans and big SUVs are superb for passengers but can be awkward in tight spaces: airport curbs, garages and narrow streets. Rear-wheel steering helps chauffeurs place the car precisely and make U-turns without multi-point maneuvers, and it makes highway lane changes feel calmer in the back seat.