Directional tyres are built to roll in one direction only. Their tread, often a distinctive V or arrowhead shape, is designed to push water out from under the tyre as it turns, and that design only works when the tyre spins the right way. To show which way that is, the sidewall carries a rotation arrow.
The rotation arrow
On a directional tyre, one sidewall is marked with an arrow alongside the word Rotation or Direction. The arrow shows the way the tyre should turn when the car is moving forward. Fitted correctly, the arrow points toward the front of the car at the top of the wheel, in other words, in the direction of travel.
This is not a suggestion. The whole benefit of a directional tyre depends on it spinning the right way, so the arrow is the single most important thing to get right when these tyres are fitted.
Why direction matters
The V-shaped tread of a directional tyre works like a channel. As the tyre rolls forward, the angled grooves sweep water outward and away from the contact patch, which is what gives these tyres their strong resistance to aquaplaning in heavy rain.
Run the same tyre backwards and the channels work against themselves, trapping water rather than clearing it. The result is worse wet-weather grip, a higher aquaplaning risk, and often more road noise and uneven wear as well. A tyre that is excellent in the wet the right way round becomes a liability the wrong way round.
Fitting and rotation
Because direction is fixed, directional tyres limit how wheels can be swapped around:
- They can be moved front to back on the same side of the car, keeping the rotation direction correct
- They cannot simply be swapped to the other side, because that reverses the direction; doing so properly means taking the tyre off the wheel and refitting it the other way, a job for a fitter, and one a garage handles when a set bought online from Tyres.co.uk is fitted locally
This is worth knowing when rotating tyres to even out wear, as a directional set can only be rotated front to rear, not crossed over.
The spare
A full-size directional spare brings a small catch: on one side of the car it will be running the correct way, and on the other it will be running backwards. As a temporary, get-you-home measure at reduced speed this is accepted, but it should be corrected as soon as practical so the tyre is turning the way it was designed to.
From the workshop: the arrow is the thing we always double-check on directional tyres, especially after someone has had a puncture fixed elsewhere. A directional tyre fitted backwards looks fine sitting still, but it is throwing away exactly the wet grip the customer paid for.
Common questions
What does the arrow on a tyre mean?+
The arrow, usually next to the word Rotation or Direction, shows which way the tyre is designed to turn. It is found on directional tyres, and the arrow must point forward in the direction the wheel travels when the car moves ahead.
What are directional tyres?+
Directional tyres have a tread pattern, often V-shaped, designed to roll in one direction only. The shape channels water out from under the tyre very effectively, which makes them strong in the wet, but it means they must be fitted the correct way round.
Can directional tyres be fitted on either side?+
Not without remounting. A directional tyre can be moved front to back on the same side of the car, but to move it to the other side it must be taken off the wheel and refitted, or it would run backwards and lose much of its wet grip.
Is it bad to run a directional tyre the wrong way?+
Yes. Running a directional tyre backwards reduces its ability to clear water, raising the risk of aquaplaning, and can increase noise and uneven wear. A directional spare used on the wrong side is acceptable only as a short-term measure at reduced speed.