svingradius

Svingradius, or turning radius, is the smallest circular path that a vehicle can follow when turning, typically achieved with the front wheels steered to their maximum angle. It is a practical measure of how maneuverable a vehicle is in confined spaces.

In road vehicles, the turning radius depends on the wheelbase (the distance between the front and rear axles), steering geometry, and tire–road grip. A common approximation for the turning circle of a vehicle’s center of gravity is R ≈ L / tan(δ), where L is the wheelbase and δ is the maximum steering angle. The inner and outer wheels trace paths with radii that differ by approximately the vehicle’s track width. The reported turning diameter is twice the turning radius.

Measurements can vary with load, passenger distribution, speed, tire condition, and road surface. Increased speed or reduced grip tends to effectively enlarge the turning radius due to slip and understeer.

Typical values vary by vehicle class. Small cars often have a turning diameter around 9–10 meters (radius about 4.5–5 meters). Mid-size cars commonly show about 10–12 meters in diameter (radius 5–6 meters). SUVs and larger vehicles may require 11–14 meters in diameter (radius roughly 5.5–7 meters). Buses and trucks generally have even larger turning radii.

Applications of svingradius include vehicle design, parking planning, and safety assessments, where a smaller turning radius usually enables easier maneuvering in tight urban environments. See also turning radius.