WheelCollider.radius

The radius of the wheel, measured in local space.

The radius will be scaled by the transform's scale.

JavaScript

collider.radius = 0.5;

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
    void Example() {
        collider.radius = 0.5F;
    }
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

    def Example():
        collider.radius = 0.5F