Motorway aquaplaning - an avoidable accident?

[DonkeyApple]

In the vide in the first post the Elise doesn't appear to have aquaplaned. It sounds like the revs drop as the driver lifts off and thus puts the car into over steer?

For the other chap to have crashed a pair of Boxsters is pretty poor.

The hassle I always had with performance cars and lots of standing water on motorways was the truck ruts in lane 1. You'd want to be in that lane due to the low speed you were travelling at but the ruts made aquaplaning an endless activity that would force you to go far too slow to be safe from causing an incident with other traffic coming up from behind in poor visibility.

I just got into the habit of exiting the motorway at the first junction on the rare occasions of a serious downpour.

[ATM]

We have another PH'er showing us his written off GT4 from a similar incident on the M5 in my Aquaplaned thread.

https://www.pistonheads.com/gassing/topic.asp?h=0&...

[jeremyh1]

I have driven well over 2 million miles on the roads of Europe and the UK
I drive 100,000 miles a year in Sprinters Transits and Pug Relays

There is no excuse if you have good tread . Just slow down .

It does not matter what you are driving get below 60 and if is really bad where it gets to you not being able to see go below 40 !

If you in a nice car with your ass close to the ground your visibility is going to be even poorer .

If you aquaplane dont claim to be a good driver !

Edited by jeremyh1 on Monday 6th December 16:55

Edited by jeremyh1 on Monday 6th December 16:55

Edited by jeremyh1 on Monday 6th December 16:56

[catman]

I noticed in the video that the loss of control coincided with the driver decelerating. When I was on a skid pan in a Cayman, I was told to keep the power on when the back end lost grip.

It was a little counter intuitive, but it worked perfectly. Although the Cayman was a superb car to drive, it didn't feel very forgiving if you did anything wrong.

[jeremyh1]

catman said:

I noticed in the video that the loss of control coincided with the driver decelerating. When I was on a skid pan in a Cayman, I was told to keep the power on when the back end lost grip.

It was a little counter intuitive, but it worked perfectly. Although the Cayman was a superb car to drive, it didn't feel very forgiving if you did anything wrong.

If you did this regularly you would be good at it and some skid pan session give you a better understanding of what happens and how to control it but most people dont have a clue !

[catman]

Hi Jeremy, Yes I agree. My experience was a Birthday gift at Porsche Silverstone. An amazing day all round, with a very experienced guy who has travelled the world and raced for McLaren, amongst others.

It was night and day compared to the generic track day experiences out there! It wasn't cheap, but as things go, it was worth every penny (of someone else's money!)

[Magnum 475]

catman said:

I noticed in the video that the loss of control coincided with the driver decelerating. When I was on a skid pan in a Cayman, I was told to keep the power on when the back end lost grip.

It was a little counter intuitive, but it worked perfectly. Although the Cayman was a superb car to drive, it didn't feel very forgiving if you did anything wrong.

This is very true of any RWD car, but especially mid-engined. Lifting off shifts the balance of the car forward and reduces grip at the rear (assuming you've got any grip in the first place). It also causes the rear wheels to try to provide some engine braking, further reducing grip.

The other thing that's been mentioned here is tyres. I've said this before - many newish cars have summer tyres that are close to being grooved slicks - have a good look at the tread on the Michelin Primacy 3 - the sipes are so thin you'd struggle to get a razor blade in them. The aim is to reduce drive-by noise, and to reduce emissions... but it does so at the expense of grip, especially in bad weather. They just don't disperse enough water. The MPSS is also hopeless in the wet, yet is standard fitment on some high performance cars. Many years ago I had an E-Class start aquaplaning on the M6 - I managed not to hit anything but it did go quite sideways for a few seconds. That car was on the half-worn Contis that it came from the dealer with; changing to PS4s (Summer) and SottoZeros (winter) removed the problem and made the car far better in all weathers. The SottoZero, and the Cross-Climates that replaced both eventually, gave far more confidence in standing water than the PS4s though.

Worth nothing - the original post shows a clear picture of the damaged Boxster's rear wheel. Check out the tyre tread.....

[DonkeyApple]

I do imagine that most of these incidences may start with a spot of aquaplaning but loft off oversteer becomes the actual reason for the incident.

[Koolkat969]

ATM said:

We have another PH'er showing us his written off GT4 from a similar incident on the M5 in my Aquaplaned thread.

https://www.pistonheads.com/gassing/topic.asp?h=0&...

The Cup 2's he was on have low aquaplaning reserves according to Tyre reviews so that is a factor to consider.

https://www.tyrereviews.com/Tyre/Michelin/Pilot-Sp...

[jeremyh1]

catman said:

Hi Jeremy, Yes I agree. My experience was a Birthday gift at Porsche Silverstone. An amazing day all round, with a very experienced guy who has travelled the world and raced for McLaren, amongst others.

It was night and day compared to the generic track day experiences out there! It wasn't cheap, but as things go, it was worth every penny (of someone else's money!)

They gave you a better car than me !

I had a Sierra Sapphire.... In 1996 when I did mine !

[DuncanM]

DonkeyApple said:

I do imagine that most of these incidences may start with a spot of aquaplaning but loft off oversteer becomes the actual reason for the incident.

Yes, that's how it looks to me.

I'm concerned at the lack of driver ownership on a lot of these aquaplaning stories, including the latest GT4 post.

[Koolkat969]

DonkeyApple said:

I do imagine that most of these incidences may start with a spot of aquaplaning but loft off oversteer becomes the actual reason for the incident.

Never been in this situation but i would assume lifting off to slow the car down will be the first reaction.

However, if that then has to potential to cause lift off oversteer then what is the better approach in a potential aquaplaning situation?

[panholio]

Cruise control is a killer for aquaplaning in standing water - I always understood that being about the continued application of the throttle once traction goes.

My old M140i was prone to being a handful in the wet, however I always put it down to the tyres (pilot supersport) and was generally very careful in standing water. My reaction has always been to lift off the throttle.

[DuncanM]

DonkeyApple said:

In the vide in the first post the Elise doesn't appear to have aquaplaned. It sounds like the revs drop as the driver lifts off and thus puts the car into over steer?

For the other chap to have crashed a pair of Boxsters is pretty poor.

The hassle I always had with performance cars and lots of standing water on motorways was the truck ruts in lane 1. You'd want to be in that lane due to the low speed you were travelling at but the ruts made aquaplaning an endless activity that would force you to go far too slow to be safe from causing an incident with other traffic coming up from behind in poor visibility.

I just got into the habit of exiting the motorway at the first junction on the rare occasions of a serious downpour.

This is such a brilliant post, the final paragraph in particular.

I hope people read this and understand how important taking responsibility for your driving/safety is, and that sometimes, that means removing yourself from the situation.

[anonymous-user]

I aquaplaned a loaner on p-zeroes, I hit standing water at about 65 on the motorway. Having done the Porsche ‘kick plate’ session I was able to control it and recover but it did pendulum about a good few times, these cars can be twitchy and you have to be v quick to catch. Sliding about at 60+ on the motorway is certainly a little more hardcore than 25+ on the skid pan.

If you’ve not experienced it before you probably won’t believe the car can just go out from under you, the next thing you know you’re at 45 degrees to the main carriageway and wrestling to regain control. Definitely keep the speed down if there is much standing water about and do a kick plate / other skid pan session occasionally. Fat over-tyred, mid engined cars are certainly susceptible.

Or in traditional ph style just blame the op and hope it never happens to you…

[kambites]

DonkeyApple said:

I do imagine that most of these incidences may start with a spot of aquaplaning but loft off oversteer becomes the actual reason for the incident.

Either lift-off over-steer or application of excessive steering lock while the wheels aren't on the ground. It's quite rare to actually aquaplane far enough on a straight road for the car to rotate significantly, but the natural attempt to correct the initial minor rotation tends to lead to you spearing off the road when grip comes back.

Fortunately (since it's not really something you practice!) my natural reaction when it happened to me was to dump the clutch and keep the steering straight.


I don't actually think lifting off is generally an attempt to slow down, I think it's a natural reaction to the revs suddenly spiking as the rears lose traction. Keeping your foot where it is and the wheels spinning until they hit the road again would be really unnatural and reducing throttle to the point that the revs are back where they were before the rears lost grip is not an easy thing to do that quickly.

Edited by kambites on Monday 6th December 19:54

[DuncanM]

Schmed said:

I aquaplaned a loaner on p-zeroes, I hit standing water at about 65 on the motorway. Having done the Porsche ‘kick plate’ session I was able to control it and recover but it did pendulum about a good few times, these cars can be twitchy and you have to be v quick to catch. Sliding about at 60+ on the motorway is certainly a little more hardcore than 25+ on the skid pan.

If you’ve not experienced it before you probably won’t believe the car can just go out from under you, the next thing you know you’re at 45 degrees to the main carriageway and wrestling to regain control. Definitely keep the speed down if there is much standing water about and do a kick plate / other skid pan session occasionally. Fat over-tyred, mid engined cars are certainly susceptible.

Or in traditional ph style just blame the op and hope it never happens to you…

I despair at your last comment, all I've seen is enabling on the other thread, and the GT4 chap has blamed tyres (arguable), and not enough traffic to disperse the water!

2 lanes flooded and hoofing it down the 3rd lane at over 60 - not the driver's fault?

[evil.edna]

DuncanM said:

DonkeyApple said:

In the vide in the first post the Elise doesn't appear to have aquaplaned. It sounds like the revs drop as the driver lifts off and thus puts the car into over steer?

For the other chap to have crashed a pair of Boxsters is pretty poor.

The hassle I always had with performance cars and lots of standing water on motorways was the truck ruts in lane 1. You'd want to be in that lane due to the low speed you were travelling at but the ruts made aquaplaning an endless activity that would force you to go far too slow to be safe from causing an incident with other traffic coming up from behind in poor visibility.

I just got into the habit of exiting the motorway at the first junction on the rare occasions of a serious downpour.

This is such a brilliant post, the final paragraph in particular.

I hope people read this and understand how important taking responsibility for your driving/safety is, and that sometimes, that means removing yourself from the situation.

Seconded. Most of DA's response are pretty much spot-on. Developing a bit of a man-crush on DA.....................

[Portofino]

Almost binned my car on the M23 in heavy rain, just after getting it.

295/20 tyres, I was going too fast, car lifted at the rear & shifted a foot or so to the left, by the grace of God, the car came back into line. Learnt a huge lesson that day. Good job I’ve got brown seats.

Edit to add, fat tyres ‘do not help’ as never had this happen on lesser tyred cars.

Edited by Portofino on Monday 6th December 20:21

[david-j8694]

I was in my aquaplane spec 981 GTS on the M1 last week and the heavens opened and wouldn't relent. I slowed from the usual making progress speeds, to 60mph middle lane, then 50mph left lane, but it was no good. The rain was torrential, wipers were at full speed and barely clearing the windscreen, plus the standing water was increasing rapidly. I knew the greater risks of mid-engine + big tyres, so I crawled the remaining mile or so (at about 40mph, and being flashed by lorry drivers) to a service station and pulled over for half hour.

I felt like a bit of a wimp at the time, but I just didn't fancy being the guy who binned his Porsche for all the passers by.

Still does amaze me the speed people are happy to carry in those conditions, though