To get an accurate toe measurement, jack up front wheels and scribe a true running line on the face of the tire. Place the gauge in front of the tires and align the pointers with the scribe lines. Then move the gauge to the rear of the tires and align the fixed end with the scribe line. On the other end loosen the thumb screws and move the slider until the pointer aligns with the other scribe line. Now read the exact toe-in on the scale. As a reminder, the scribed line can be anywhere on the tire face.