Toe (wheel alignment)
Definition
Toe is the angle at which the wheels on an axle point inward (toe-in) or outward (toe-out) when viewed from above, measured in degrees or millimetres; most front-wheel-drive cars run a little toe-out or zero at the front and rear-wheel-drive cars a little toe-in, with the rear axle usually set to slight toe-in for stability. It is the alignment angle that wears tyres fastest: as little as 1-2 mm of error scrubs the tread sideways every metre, producing feathered edges you can feel by hand, and it also affects straight-line stability and steering centre. Front toe is adjusted at the tie rods, rear toe at eccentric bolts or adjustable links where fitted; the thrust angle (direction the rear axle points) must be corrected first so the steering wheel ends up centred. Toe goes out of specification after tie rod, rack, control arm or strut work, after kerb impacts, and when bushings wear, so any suspension repair should end on the alignment rack. No fault codes, but the ESP steering angle sensor must be re-zeroed after an alignment on many vehicles (otherwise C0051/U0126-type plausibility faults), and modern cars also need camera and radar calibration if the thrust angle changed.