What does minimum turning diameter mean?
3 Answers
Minimum turning diameter refers to the diameter of the trajectory circles formed respectively by the front outer wheel, rear inner wheel, farthest point, and nearest point when a vehicle turns with the steering wheel turned to the limit position. Minimum turning diameter (M) is actually a non-standard term indicating vehicle performance. Turning diameter is the standard term, which is a parameter indicating the flexibility of a vehicle's turning performance. During the vehicle steering process, when the steering wheel is turned to the left or right limit position, the trajectory of the center of the outer steering wheel's footprint on its supporting surface forms a circle, and the largest diameter among these is called the vehicle's minimum turning diameter. The turning diameter is directly related to wheelbase, track width, and the steering wheel's maximum turning angle. The larger the wheelbase and track width, the larger the turning diameter. The greater the steering wheel's maximum turning angle, the smaller the turning diameter. It largely represents a vehicle's ability to pass through narrow curved areas or circumvent impassable obstacles. The smaller the turning diameter, the better the vehicle's maneuverability. For ordinary vehicles, the turning diameter is approximately 10-12m.
The term 'minimum turning diameter' sounds quite technical, but simply put, it's the smallest circle diameter your car can make when you turn the steering wheel all the way to the lock. Take my own experience for example: last time I was driving my friend's large SUV and trying to make a U-turn in a narrow alley, it took me three attempts to get through. Only later did I learn its turning diameter was 11.8 meters. Meanwhile, my compact hatchback has just 9.6 meters, allowing me to easily park in those tight supermarket parking spots in one go. This number directly affects daily maneuverability, especially in old town areas with tight corners. Cars with smaller values have tighter turning radii, allowing you to glide through with just a slight turn of the wheel when at full lock. But if the value is large, encountering a dead end or needing to make a U-turn on a two-lane road can really wear down several layers of tire tread before you can get out.
When choosing a car, I paid special attention to the turning diameter. The salesperson's claim of a '5.9-meter turning diameter' sounded quite impressive. In actual driving, I realized how much it helps with parallel parking. Last time, I drove a colleague's rear-wheel-drive car into a multi-story parking garage with a claimed turning diameter of 10.2 meters—I almost scraped a pillar while making a U-turn in a 5-meter-wide lane. Later, I learned from research that compact cars with shorter wheelbases usually perform better in turning. For example, the Wuling Hongguang MINIEV has a turning diameter of just 4 meters, while luxury cars with extended wheelbases can exceed 13 meters, requiring an extra half-meter margin when turning in underground garages.
