multilink

A multilink suspension uses at least three separate arms, or links, to locate each wheel in space rather than relying on a single rigid axle or wishbone pair. The arms connect the wheel hub to the chassis at different mounting points, allowing engineers to control the wheel's vertical travel, camber angle, toe angle, and anti-roll stiffness almost independently. This geometry gives designers far more control over how the tire meets the road during cornering, braking, and acceleration than simpler suspension types.

The most common configuration pairs three lateral arms (upper, lower, and trailing) with one longitudinal arm, though some designs use four lateral arms or multiple longitudinal members. Each arm typically has a compliance bushing at the chassis end and a ball joint or bearing at the wheel end. Mercedes-Benz, BMW, and Audi popularized this layout in the 1990s; it is now standard on most mid-range and premium sedans and crossovers. Rear multilink suspensions are more common than front, since rear wheels do not need to steer.

Geometry and Performance Trade-offs

By carefully choosing arm lengths and mounting angles, engineers can dial in nearly any combination of roll center height, instant center location, and suspension compliance. This precision makes multilink attractive for performance tuning: a sports car can reduce body roll and limit dive under braking, while a luxury sedan can isolate bumps and road noise. The cost is complexity: more arms mean more bushings, more ball joints, more parts to wear and more geometry to get wrong in accident repair.

Multilink suspensions are sensitive to bushing wear and misalignment. A worn compliance bushing shifts the roll center and changes the car's handling response gradually over time. Aftermarket performance bushings reduce compliance but often amplify road noise and vibration into the cabin. Front-end alignment becomes a three-or-more-degree-of-freedom problem, which is why multilink cars require computer-controlled alignment racks and expert technicians.

The name comes directly from the structural logic: multiple independent links, rather than the single semi-trailing arm or pair of wishbones in older designs. It is sometimes called independent multilink or IRS (independent rear suspension) when used at the rear axle, though IRS is a broader term that includes other geometries. Double-wishbone and A-arm suspensions are simpler cousins that use fewer links and less tuning flexibility.