Have you ever aquaplaned?

[Tailhappy]

Just wondering about this. I hear about this happening but have never experienced it myself. I am not sure whether it is governed by the tyre width, tread pattern, speed or design of the car.

I have driven quite quickly along awash roads and never felt grip go or loss of traction. Sometimes through badly flooded sections I feel a tug on the steering and the car slow a bit, but never like I am riding up on the water...

I have always used Dunlop Aquajets (the ones that have holes all the way around) on my Estelles/Rapid so maybe it is the good tyres that have saved me in the past?

If you have ever aquaplaned, what car was it, what tyres and what speed? Also how fast were you traveling? What happened?

All thoughts and experiences welcome.

[AlphaPapa]

I have aquaplaned in the octavia and a clio. Driving on the motorway in heavy rain is normally when it happens. You get grooves in the tarmac where water collects and you will hit a spot thats just the right depth and the car will go very light, you just hope to god it stays in a straight line.

[ScoobyChris]

True aquaplaning is rare (water drag and viscoplaning are actually far more common and tend to occur more at lower speeds than high).

Water drag is where the tyre hits a wall of standing water and this slows the tyre down due to simple momentum.

Viscoplaning is where the thin film of water left after the tyres have dried the road is enough to change the local coefficient of friction so the tyres slide.

I think there are lots of factors but the main ones are the ones you mentioned, ie tread depth, tread pattern and the speed you enter the water at, ie how well the tyre can shift water and maintain rubber contact with the road. Once this ability is saturated, you'll lose contact with the road.

My old Disco had M+S off-road tyres on it and that cut through even a few inches deep of standing water without problem. By comparison, my other cars have all worn normal "summer" tyres and you can feel the difference when negotiating standing water in the road, especially at speed, so ideally you either want to avoid driving through it, or slow down to maximise the amount of grip you have available to you, avoiding turning the wheel until you feel the grip come back!

Chris

[Guest musky]

In a Capri at about 80ish very unnerving just like ice, basically don't change anything and hope it goes away! Never happened in this car.

[yegnold]

Not 4 wheel aquaplaned but I did lose all grip on my front left wheel on a slight corner in the wet one time. The car stuck to the road fine but I could tell only one front wheel was touching the floor

[devonutopia]

Yep - Happened to me, both on the motorway, and on a wet trackday (although on track it's very short distances before grip is restored) - On the motorway it's quite scary, and soon makes me get a tight grip on the steering wheel. :eek: I think the key is to not release the throttle right off, and definitely not to try and brake - all of which could potentially unbalance the car whilst "light" and cause an accident.

Either way, it pays to be concentrating 110% in poor conditions.

[Sammycarp]

Twice - both in my old Hyundai Accent, both at 70-80 (indicated). First was shortly after I got the car, took a corner at speed in the rain, and the back end over took the front. Was very lucky to walk away (ok, drive away) from that one. Second time was travelling up the A1, felt the front end go all light, and carried straight on across the white line partially into the other lane.

Car was running 155/55/R14 budget tyres.

[P13SST]

I had it on the motor way in heavy rain combined with a wave of water created from a lorry going in the opposite direction couldn't see or have control for about 3 seconds. Best way to get through it is to not do anything (i.e don't alter your throttle position or move the steering wheel). Didn't help that I had been up for 50 odd hours and it was 4am in the morning

[ScoobyChris]

On the motorway it's quite scary, and soon makes me get a tight grip on the steering wheel. :eek: I think the key is to not release the throttle right off, and definitely not to try and brake - all of which could potentially unbalance the car whilst "light" and cause an accident.

Absolutely - the key is to maintain the car's stability as best you can with the aim of coming out of the water onto the tarmac as smoothly and undramatically as possible. In most cases, I think this just requires easing off the throttle a little, keeping the steering wheel straight and avoiding using the brakes, however some ESP systems may be able to sort it all out for you in which case you want to steer in the direction you want to go (and hope the car can sort it for you )

Interesting comment about tightening the grip on the steering wheel - in a situation where one wheel is in the water and you're fighting the drag, I think it definitely can help, but where both wheels are in the water, I think a lighter grip might offer more as you'll be able to feel exactly when the tyres regain grip, which may be useful, especially if you're waiting to perform some firm braking or steering in a short amount of space....

Chris

[devonutopia]

I think tightening the grip is merely symptomatic of being scared s***less by the feeling of being out of control, to a degree. But I know what you mean.

[Babs]

Yes, and across 3 lanes of M4 at 60mph :shock:

Luckily was 1am!

[Jim H]

I have in my old Metro. I suppose it was easy as it was on small skinny 135 / 12 tyres and my steering wheel was bolted directly to the rack via the column, ie. no PAS or UJs.

I don't think I have done it with my Furby yet.

[yegnold]

I think it's easier to aquaplane on wider tyres, personally...

[Babs]

I think it's easier to aquaplane on wider tyres, personally...

Yup

I never managed to lose traction riding a mountain bike!

[ScoobyChris]

I think it's easier to aquaplane on wider tyres, personally...

I've been wondering about this too, but thinking about it, all else being equal, I'm not sure the width of the tyre actually makes any difference. My thinking was that the difference between traction and aquaplaning is the amount of water required to sit between the tarmac and the tread which will be identical to the contact patch size in each case?

However, doing some Googling, I found an "aquaplaning formula" which seemed to only mention tyre pressure as a factor and suggests that you can raise the speed at which aquaplaning occurs by putting more air in your tyres ... which has the net effect of (marginally?) reducing the size of the contact patch.

Saying all that, I've not driven a car on standard tyres that wouldn't easily "aquaplane", be it on skinny tyres or on wide expensive ones so now I just drive on the drier/shallower lines so I can keep the pace up

Chris

[yegnold]

Two cars, same weight.

One has 10cm wide tyres.

One has 20cm wide tyres.

The thrust upwards per square centimetre needed to be provided by the water on each tyre to raise the car off the tarmac on the SECOND car is exactly half that of the first tyre.

So by that calculation, wider tyres = easier to aquaplane?

[JimmyW]

I have,twice!:eek: Once in my Mams Ignis doing 60 round a gentle bend when someone pulled out,gently onto the brakes and did a bit of a slide but it gained traction pretty quickly

Second time was in my jimny with a set of mud terrains on,driving through the school carpark,which is that smooth tarmac cycle tracks are made out of,admittedly a was going a bit fast,spotted that teacher that is always complaining about the student drivers so i changed my direction a bit too quick and braked at the same time,sending me into waterlogged grass,lucky for the mud terrains,otherwise i'd be a bit stuck,but wouldn't have happened if i had tyres with rain groves. . . .and that teacher complained about me too

[Captain Sisko]

Not sure if I have truly aquaplaned but on the Saturday (day before the superrally) going to Birmingham the car felt like it hit a puddle on the inside lane a few times (under heavy rain) although didnt see any large puddles forming and the car sort of meandered (if thats the right term) speed about 70/75.

I did ease off afterwards to about 60 until the rain subsided.

[apd007]

Yes, once, and it is a bowel loosening experience that I don't ever wish to have happen again.

Front wheels in a Ford Sierra coming home from a football match one boxing day night, speed was, ahem, quick. I honestly thought my steering rack had broken as all vibrations from the front wheels suddenly ceased and I distinctly remember moving the steering wheel slightly from side to side and it having no effect on direction. I'm not sure how long the front wheels where aquaplaning for but I seem to recall I had time to consider my options and trying to work out how to get to the hard shoulder with no steering when the vibrations came back up through the wheel. Obviously, I'd lifted off once I lost steering input and that is what helped to get the tyres back on the road.

[andypandypoos]

I have, felt kinda like driving on ice

Yup

I never managed to lose traction riding a mountain bike!

I've lost traction on my mountain bike, and often. but it was most likely down to the surface I was riding on being wet and/or loose

[bengie]

only once that i can recall and as said all controls go extremely light and have no appreciable affect on cars travel :eek:

other than that one morning i was taking pandy to work and there was a mahoosive puddle under a flyover on a local bypass that i saw and slowed down for, the car next to us didn't slow and hit it at around 70mph only to throw a huge bow wave over us so thick for a couple seconds we couldn't see a single thing then as soon as my wipers had cleared the screen enough to see this pillock was spinning next to us and we were only on a two lane bypass!!! :eek:

he ended stuffing it into the barrier along side us and luckily didn't touch us, we quickly pulled over onto the side of the road and ran back to see if everyone was ok and he was already on the phone to the police and all was well except his pants and car

[andy2407]

Two cars, same weight.

One has 10cm wide tyres.

One has 20cm wide tyres.

The thrust upwards per square centimetre needed to be provided by the water on each tyre to raise the car off the tarmac on the SECOND car is exactly half that of the first tyre.

So by that calculation, wider tyres = easier to aquaplane?

Not sure that is the case - I'll try to explain although I'm no expert and may be wrong!

Lets say the contact length in the first case is 10cm. Therfeore, contact area is 10 * 10 = 100 cm^2

Now the cars are the same weight, so for the second car the contact area will also be 100 cm^2

Contact length is 100 / 20 = 5 cm

So in the second case, the thrust upwards will be working over a shorter length but most importantly over the same area.

This suggests that tyre width will not affect the tendency to aquaplane.

Have a read of the "Fat or Thin" section at Car Bibles : The Wheel and Tyre Bible Page 2 of 2 which is what got me thinking. It suggests that wide tyres grip better but not for the obvious reason.

[sms]

last time was on the m5 back up from wsm meet and was only doing 40mph as the weather was that bad, soon got off the motorway and drove the A roads back home.

Things that help not to aquaplan is a heavier car and lots of tread, however when you do aquaplan its the water build up under the wheel which suddenly slows you and lifts you up. the lift is as the water disappears under the tyre iirc.

[vRSLen]

Aquaplaned? Yes, big style a few yaers back in an MX5 with F1 tyres. Thought wet road, no problem,

but then the water got VERY deep and I was drifting sideways at about 60 MPH, heading for an

oncoming car :eek:

Managed to get it under control through shear luck, but have far more respect for standing

water now

[bengie]

Not sure that is the case - I'll try to explain although I'm no expert and may be wrong!

Lets say the contact length in the first case is 10cm. Therfeore, contact area is 10 * 10 = 100 cm^2

Now the cars are the same weight, so for the second car the contact area will also be 100 cm^2

Contact length is 100 / 20 = 5 cm

So in the second case, the thrust upwards will be working over a shorter length but most importantly over the same area.

This suggests that tyre width will not affect the tendency to aquaplane.

Have a read of the "Fat or Thin" section at Car Bibles : The Wheel and Tyre Bible Page 2 of 2 which is what got me thinking. It suggests that wide tyres grip better but not for the obvious reason.

but a wider wing gives more lift and the tyre is in effect a wing in this instance.