WheelCollider.steerAngle

Steering angle in degrees, always around the local y-axis.

JavaScript

// steer forwards

collider.steerAngle = 0;

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
    void Example() {
        collider.steerAngle = 0;
    }
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

    def Example():
        collider.steerAngle = 0

At high velocities use only small steer angles; a few degrees should suffice.