On this page
What is aquaplaning?
Aquaplaning is when the tyre loses contact with the road and glides on a film of water. It happens when there is more water to clear than the tread grooves can push out.
At that moment the steering and brakes have very little effect, because the wheels no longer grip the road.
What are the main causes?
The main causes are speed, the condition of the tread, tyre pressure and the amount of water on the road. They often combine.
- Speed: the faster you go, the less time the tread has to clear the water.
- Worn tread: shallow grooves clear less water.
- Low pressure: the tyre deforms and drains water less effectively.
- Puddles and standing water: dips, ruts in the lanes and underpasses collect water.
How do you recognise aquaplaning while driving?
You recognise it because the steering suddenly goes light and the car does not respond as it should. Other signs:
- the engine revs rise without the car accelerating;
- a feeling of floating;
- the tyre noise changes or fades.
What should you do if the car aquaplanes?
If the car aquaplanes, do not brake hard or steer sharply: ease your foot off the accelerator gradually and keep the steering wheel straight.
- release the accelerator gently;
- keep the steering wheel pointing in the direction of travel;
- wait for the tyres to regain grip;
- only then correct your course and brake gently, if needed.
What role does the tread play?
The tread is crucial: its grooves are there precisely to clear water. The more worn the tread, the sooner aquaplaning sets in.
The legal minimum for cars is 1.6 mm, but for safety in the wet many people advise replacing tyres sooner. The EU tyre label also shows the wet grip class, from A to E. Tread depth is also one of the things checked at the roadworthiness test.
Does tyre pressure make a difference?
Yes, pressure that is too low increases the risk of aquaplaning because the tyre deforms and the tread drains less well. Check the pressure when the tyres are cold, using the values given by the vehicle manufacturer.
If the pressure warning light comes on, do not ignore it: the guide on the tyre pressure warning light explains what it means. A tyre slowly losing air may have a puncture: see tyre losing air.
Tyre going down or damaged in the rain in Milan?
If a tyre goes down or you get a puncture in the rain, do not improvise at the roadside: SOS Tyre comes out 24/7 across Milan and its province, in 30 minutes on average, to wherever the vehicle is. Call +39 377 326 0999 or use the request for assistance.
Frequently asked questions
At what speed is there a risk of aquaplaning?
There is no single speed: it depends on the amount of water, tread depth, pressure, tyre width and vehicle weight. In general the risk increases with speed, so in the wet and with visible puddles the rule is to slow down early.
Are wide tyres more prone to aquaplaning?
Broadly speaking, a wider tyre has to clear more water to stay in contact with the road, so all else being equal it can be more prone to aquaplaning. A lot depends, however, on the tread pattern and how worn it is.
Is cruise control dangerous in the wet?
Many owner's manuals advise against using cruise control on wet or slippery roads, because if grip is lost the system may keep delivering power. Check your vehicle manufacturer's guidance.
Can aquaplaning damage the tyres?
Aquaplaning itself usually does not damage the tyre, but the resulting loss of control can lead to hitting kerbs or barriers, damaging tyres and wheels. After an episode involving an impact, check the sidewalls and wheels for bulges or deformation.