Tracking is the Toe angle setting of a vehicles front wheel alignment.
Toe angle is the forward direction of the wheels. The wheels of a vehicle need to roll freely along the road, to do this they both need to point in the same direction.

The diagram to the right shows when tracking is set correctly both front wheels point in the same direction. If the wheels are pointing inward, they are of toe-in (or + toe) and if they are pointing outward, they are toe-out (or - toe). The red arrows show the directions misaligned wheels will try to take, the wheels cannot go in different directions, so they are dragged sideways as the vehicle moves forward. The term given to the effects of this dragging is known as tyre scrubbing.

Vehicle energy is transferred to the tread of the tyres against the road to overcome resistance and make the vehicle move. With poor alignment energy is absorbed by completely unnecessary rolling resistance created by the action of pulling or pushing the tyres sideways in a different direction to which they want to travel. The scrubbing effect also cuts the grip your tyres have on the road and further energy transfer is lost.

Department for Transport Case studies have found that the poor tracking has a staggering effect on increased fuel consumption and tyre life. Check out the benefits page for how poor tracking wastes money, harms the environment and reduces safety on our journeys.

Even when tracking is kept correct, tyres develop natural wear characteristics of the vehicle, the steering wheel can end up to one side whilst the car is going in a straight line, this too is corrected by tracking adjustment, it simply requires adjustment at both road wheels.

It is quite common for owners paying for tracking corrections to still suffer premature/uneven tyre wear a few months down the line, with a likelihood of inaccurate adjustments.

Paying for adjustments does not mean your tracking is correct, you only know for sure if you can check it yourself.