Turning radius which is also called as turning circle is a term used to describe the size of circular turn taken by a vehicle. In short, you can say that when a vehicle takes a U-turn, the measurement is taken. Here the size of the circle is actually the diameter and not the actual radius. Very less is used the term Turning Circle, but mostly people use turning radius.
When it comes to measuring the radius of a vehicle, it could be curb or curb to curb turning circle. A tight turning radius could be termed to those vehicles which have very small turning circle. The turning circle of a vehicle is the size of the smallest turn (circular) that the vehicle can take at the max. To consider a car or a truck, it is important to know about its turning radius which helps you in finding out its performance. The turning radius of a vehicle depends on various factors. One of the major factors is the width of the wheelbase that determines the distance of front tires. It is obvious that a smaller wheel base would bring tighter turning radius whereas, larger wheelbase such as those of large trucks will provide larger turning radius.
Other factor in turning radius of a car is its steering gear box. All gearboxes are created differently and so the radius varies. Different types of steering setups are available with different advantages each possesses in turning radius. Earlier, the most oldest and basic type of steering is known as rack-and-pinion. Basically, the type of steering system has an effect on vehicle’s turning radius. In classic rack and pinion car, the steering wheel does not make tight turn.