Turning radius explained

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added in General terms by Beta

[img] Each wheel, front and rear, aligns with a radius of a common circle. Since the rear wheels are stationary, the center of this circle must coincide with the rear axle's line. Ackermann geometry (2010)

The turning radius of a vehicle is a critical measurement that quantifies the smallest circle or curve it can navigate within while turning its front wheels to their maximum steering angle. This measurement is instrumental in determining a vehicle's maneuverability and its ability to make turns in confined spaces without colliding with obstacles or encroaching onto other lanes or surfaces.


The turning radius is a fundamental vehicle design characteristic that influences real-world performance, such as parking and navigating tight corners. Measured in feet or meters, a smaller turning radius signifies greater maneuverability in urban settings.

Key Factors:

  1. Wheelbase: The distance between a vehicle's front and rear axles, known as the wheelbase, significantly impacts its turning radius. Vehicles with longer wheelbases typically have larger turning radius, necessitating wider spaces to make turns.

  2. Steering Angle: The maximum angle to which a vehicle's front wheels can be turned, often referred to as the steering angle, directly affects the turning radius. A larger steering angle enables a vehicle to make tighter turns.

  3. Tire Size and Grip: The size and grip characteristics of a vehicle's tires also play a role in determining the turning radius. Wider, grippier tires can improve a vehicle's ability to make sharper turns.

  4. Steering System: The design and efficiency of a vehicle's steering system impact its responsiveness and turning performance. Well-designed steering systems can enhance maneuverability.

  5. Vehicle Type: Different types of vehicles, such as compact cars, SUVs, trucks, and buses, have varying turning radius due to their unique sizes and configurations. Smaller vehicles generally have smaller turning radius.