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Goodness what an idiot, I resalise now people mean my friend and the OP were driving, er, Bavarian things. No I say, steady on chaps, bit below the belt what, er....
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There could be a number of issues here.
We do not know the tread depth or brand of tyre. Both of these will make an enormous difference. 2mm of tread and cheap tyre is a bad idea in very wet conditions.
Does the fact that the BMW had RWD make a difference in a similar way to having RWD on snow? I would think that it does. Suddenly losing traction at the rear is worse than losing traction at the front when travelling in a straight line.
Was the driver accelerating as he hit the puddle, maybe under maximum throttle? This would facilitate to spin the wheels.
As an aside...I have two cars, a 1.6 petrol (120bhp) and a 2.0 TDCi (130bhp). Both have the same brand of tyre. The Diesel, due to its huge torque will spin or aquaplane its driving wheels a lot more easily than the petrol when accelerating through standing water.
Yes, overall, the lack of driving skills is probably what upended the BMW.
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Does the fact that the BMW had RWD make a difference in a similar way to having RWD on snow? I would think that it does. Suddenly losing traction at the rear is worse than losing traction at the front when travelling in a straight line.
Yes, that's a factor. When a RWD car loses traction at the back it tends to yaw (turn). With FWD you just tend to lose speed - the drag of the rear wheels tends to keep pulling the car straight.
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As a local who uses the M20 & M26 on a regualr basis i have a couple of observations:
Fully support the look well ahead, watch your speed in the wet brigade however part of the problem is the appaling state of the road surface on large sections of both motorways.
The fast lane of the M26 is probably used more that the slow lane due to the fact that its a 2 lane motorway (bad case of ignoring traffic growth numbers when it was built back in the 80s) and as such has some severe road wear especially Maidstone bound. The top layer of ashphelt is coming off which means that when it rains this area fills with water. When you factor in the lack of any street lighting and those users who are unfamilliar with the road then it becomes a skid pan at speed at night in the rain.
I actually wrote to the Highways authority on their web site highlighting this issue and was told that due to lack of budget they would be resurfacing in the new financial year. This was in 2004 and its still not done GGGRRRR...Need i say more
--
\"Eagles may fly in formation but Weasels dont get sucked into jet engines\"
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Goodness what an idiot, I resalise now people mean my friend and the OP were driving, er, Bavarian things. No I say, steady on chaps, bit below the belt what, er....
Sorry old man , nothing personal .
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Well said it before and will say it again if you've been bought up on the fwd fodder jumping into a poerful rwd may come as a shock. It's what you're used to !
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Firstly, its good to hear no one was hurt, just pride maybe?
But driving to the conditions, not the speed limit is the most important part of driving that is most sadly lacking imo.
An accidental bump in the snow at 5mph is because of driving too fast for the conditions/car/driver. Hitting a big puddle (whatever the state of the road) at 70 is as bad or worse. If you know the road you should expect the puddles. If you dont know the road you should be aware of the conditions. Puddles dont suddenly happen; they need rain/water etc.
Thats the trouble with speed cameras; its made the majority of people think the speed limit is safe in all conditions ! It's not ! Sometimes its way too fast, sometimes its way too low but its appaling lack of decent driving ability that is the major problem that is continually ignored !
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Some months ago, I posted on the topic of 50% of vehicles slowing down to below 40 mph on the A1 in monsoon conditions whilst the other 50% (inc artics) ploughed on at top whack through the spray. I was one of the former group - and was termed a 'mimser'. Presumably, the chaps in the latter group (the non-mimsers) are allowed to blame the poor state of the road when they spin out of control.
PIle-ups frequently occur in these conditions and the police always report on the tv news that 'drivers were going too fast for the conditions'.
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Ah Waino accidents are always something elese's fault. :-)
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Years ago it was said that all tyres will aquaplane above 50 mph, and so that was the recommended maximum speed in rain of any quantity.
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Not so sure about 50 mph being true figure now but I agree with the theory.
Depends on the size of the tyre, the car, how worn the tyres are, how much weight in the car etc etc but at some point every tyre will aquaplane !
But its nice to know that so many people are not aware of this and drive on at high speed whatever the conditions !
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Some people don't seem to have any fear.....or have so much lack of understanding they don't know enough to formulate any fear
I like to press on and will often press on enough that i'd not be willing to admit the end result on here
but
there are times the conditions worry me.......heavy rain on a motorway is one of them.... and yet some 'carry on as normal'.....i'd factor in tyre condition, vision, carriageway condition, volume of traffic.... and then choose my speed...
some just do the same speed they always do
driving to Scotland before Christmas was a good example.........up the M40/M6 at midnight plus (to miss the traffic and camera vans).....but the fog was really thick.....didn't end before Preston
I sat following the lorries at 56mph for ages.......because i couldn't see a thing, virtually nothing.... the amount of people that came winging past at 80-90 was truly frightening.......they obviosuly don't think 'what if'
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lack of understanding so they cant formulate fear.
So accurate !
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If you're following lorries at 56mph in heavy rain, all you are going to see is all the spray they kick out (i.e. pink fluffy dice all visibliity). While going past at 90mph is pretty daft, getting past the lorries, so you've got some clear road in front of you will do wonders for your visibility. Better to see where you are going at 65mph than being blind at 56mph.
I remember driving along a motorway in very heavy conditions once, where I was aquaplaning all the time so could barely get above 35mph (like most of the other car drivers). However the HGVs didn't suffer such problems due to their weight, so could carry on at 56mph. So the motorway ended up in a bizarre state with HGVs overtaking all the cars drivers.
It seems lane discipline gets even worse in wet weather, and lane hogging even more persistent. I think some drivers get too scared to change lanes, and this results in forced undertaking moves and nervous brake stamping all over the place.
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Anyone know what contribution tyre width makes to aquaplaning? Simple physics suggests the same car with wider tyres will aquaplane sooner because the downward pressure is less. (A crude calculation says that the tyre-to-ground pressure on a 225mm tyre will be about 9% less than on a 205mm tyre on the same car.)
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Dont know the figures but agree wider will aquaplaner sooner, whatever car they are on.
In rallying, race etc the wet/snow/mud tyres will be narrower and sometimes taller profile to enable more pressure on surface.
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If you're following lorries at 56mph in heavy rain, all you are going to see is all the spray they kick out (i.e. no visibliity).
didn't say i was right up their 'arris.........left an enormous great gap and let them get on with it........saved me having to strain to see........and if they start to slow down or brake.... so will I... their braking distances are far greater than mine, which gives me a lot of leeway
was far happier in the inside lane as well........most of the high speed people were not (and do not ) use the inside lane, so far less chance of someone ramming me up the rear
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Fair enough, I didn't spot your foggy comment. I was assuming spray from heavy rain. Their long braking distances are fine when you're behind one, but not so good when one is behind you. I nearly got squished once by being Mr.End-of-Stationary-Queue on a motorway when Mr.23-Hour-Shift HGV driver got very large very quickly in my rear view mirror. Thankfully he woke up in the nick of time to find his steering wheel could guide him down the hardshoulder. He stopped about 10 car lengths ahead of me...gulp.
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it's a horrible feeling isn't it.........knowing there's nowt you can do
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"I suppose what they have in common is that they both lost it on motorways, something that seems virtually impossible to me without going to lunatic extremes."
Not long after passing my test I hit a large puddle at 30mph and was shocked to find the steering being pulled to one side. It was probably differential drag due to the puddle being deeper near the kerb. Anyway, a deep puddle can easily caush a crash especially if you are driving one handed, with but a light grip on the steering wheel. I do wish that had been mentioned in the theory test.
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in that case the Highway's Agency should be held to blame. They have a responsibility to make sure that puddles are not on motorways and if they are then there should be heavy signage to say so.
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Wot?
So if it a real raining-cats-and-dogs day, and water is pooling on the road, and some moron driving at the wrong speed for the conditions whacks his car into a puddle, and either aquaplanes or 'literally' floods the engine, then somebody else is to blame?
Dear Lord, it is true what some people say about the 'blame culture'.
Rule #1 I learned many years ago when i started driving - in the event of wet weather or other adverse conditions SLOW DOWN.
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Anyone know what contribution tyre width makes to aquaplaning? Simple physics suggests the same car with wider tyres will aquaplane sooner because the >>downward pressure is less. (A crude calculation says that the tyre-to-ground pressure on a 225mm tyre will be about 9% less than on a 205mm tyre on the >>same car.)
Added to the pressure per unit area, there's also the extra distance the water has to travel from the centre to the edge, i.e. on the above water needs to travel ~9% further, with less unit pressure pushing it , so will travel slower for longer - presumably the point of 'rally' bad weather tyres being narrower too . I'm not sure how much water is 'pushed' forward or exits backwards though which will affect calculations too, as will tread pattern and depth.
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All a wider tyre does is to chnge the *shape* of the contact patch.
The vertical load on a tyre is governed by the vehicle mass distrution and any cornering or braking dynamics.
The contanct pressure is largely governed by how much air pressure is in the tyre.
The area of the contact patch follows - Area = Force / Pressure.
So, putting wider wheels on (at the same inflation pressure) doesn't change the average pressure in the contact patch.
The phrase "pressure per unit area" is a tautology, and isn't really meaningful.
Using this type of argument, you could argue that for wet weather, the last thing you want is a circular contact patch, because then the water in the centre of the patch has a long way to go in any direction. If you fit a very wide tyre, there's a short path to the front or rear - if you fit a very narrow tyre, there's a short path to each side.
However, for other road conditions, a more circular contact patch is a good thing, because it gives good balance between longitudinal and lateral force generation capability.
A thin tyre is used in loose conditions in rallying, to maximise traction, at the expense of lateral grip, because the skilled drivers can skid the car to point the tyres in the direction they wnt to go, rather than relying upon steering actions as we mere mortals do.
Number_Cruncher
[pedant]
The phrase "pressure per unit area" is a tautology, and isn't really meaningful.
[/pedant]
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one thing that hasn't really been mentioned yet.....is that in heavy rainfall, the edge of a carriageway gets a puddle first.......which is often the hard shoulder and outside lane on a motorway/dual carriageway....
how many people don't bother to think about this and plough on regardless in the outside lane ?
...and then it's 'all of a sudden a puddle appeared'......what a surprise
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This is a good point. Modern roads (by which I mean those built in the last 20 years or so) do seem to be prone to very poor drainage. Stretches of the M40 around the Oxfordshire/Warwickshire borders spring to mind as particularly noticeable examples of this.
I suppose that the problem is in engineering the road bed to have just enough camber to drain effectively without making it unpredictable to drive along, but surely this ought to be possible to arrange.
There again, people could always stop relying on having 500 airbags, cruise control, ABS, TCS, ESP, EBD, XYZ and so on and actually learn something of the physical properties of rubber on tarmac and the need to take account of conditions and moderate speed accordingly...naaah, it'll never catch on.
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There again, people could always stop relying on having 500 airbags, cruise control, ABS, TCS, ESP, EBD, XYZ and so on and actually learn something of the physical properties of rubber on tarmac and the need to take account of conditions and moderate speed accordingly...naaah, it'll never catch on.
Once again, it is the problem of people not realising that the speed limit is in fact... a LIMIT! NOT a recommendation!
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>>The phrase "pressure per unit area" is a tautology, and isn't really meaningful.
Indeed it was, I blame it on low pre-lunch blood sugars.
However,
>>Using this type of argument, you could argue that for wet weather, the last thing you want is a circular contact patch, because then the water in the
>>centre of the patch has a long way to go in any direction. If you fit a very wide tyre, there's a short path to the front or rear - if you fit a very narrow tyre,there's a short path to each side.
But does this take into consideration the extra amount of water a wide(r) tyre has to move away , compared to a narrow(er) tyre.
If you combine that effect with the shorter path to the front (in a wider tyre, from your argument prec.) where, presumably you don't want the water to go
(since you don't want water in front of the tyre) it would seem to me that you're going to rapidly reach the aquaplaning point - that is, there's a quicker
transition from non-aquaplaning to aquaplaning. The narrow(er) tyre has the adavantages of: less water to 'lateralise' initially & quicker movement
of that water to the 'safest' place i.e. the side of the tyre?
Assuming tyre pressures, condition & tread design efficiency are equally good/efficient in both.
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Conventional wisdom is that very wide tyres can let go more easily in the wet than you might think.
Wide tyre=bigger footprint=lower pressure for same weight=easier aquaplaning.
When there's a lot of water about there will be puddles. When there are puddles if you are going at all fast you will aquaplane. When you do, the important thing is to be running straight, so that when the tyres touch ground again there is no untoward tendency to jink or swerve.
Why am I the only person who points this out? Has no one else aquaplaned on a number of occasions and got away with it? Or have they just not noticed?
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"Why am I the only person who points this out? Has no one else aquaplaned on a number of occasions and got away with it? Or have they just not noticed?"
I have never knowingly aquaplaned, but then again I tend to slow down in heavy rain. I did nearly crash not long after passing my test due to hitting a puddle, so maybe the unexpected laundry bill educated me to be extra careful. I am often astonished at how fast some people go in bad road conditions. During the recent snow falls I was overtaken by several high speed vans while going at what I thought was the maximum safe speed given the conditions.
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>>Conventional wisdom is that very wide tyres can let go more easily
My wide tyres absolutely are prone. However, even then I wouldn't say excessively so, certainly not so I would lose control or be caught by surprise. Last time I quoted the width of my tyres I got it wrong, but I know they're wide.
Its all part of being aware of and capable with the type of vehicle you are driving. Be that a heavy, relatively unstable SUV such as my Landcruiser, or something low and light like a sports car. I don't know where its gone wrong. We seemed to have moved away from most people being generally proud of their driving to a situation where loads of people are totally anal about the whole thing to a point of inducing vomiting and a whole bunch of other people who simply don't care.
>>Has no one else aquaplaned on a number of occasions and got away with it
Not noticed, would be my guess. If the car aquaplanes at a point when you are not braking, accelerating or turning, then providing it doesn't do it for long then it may well escape your notice.
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the important thing is tobe running straight, so that when the tyres touch ground again there is no untoward tendency to jink or swerve.
Even if no one has noticed their car aquaplaning, many must have noticed that if the wheels on one side of the car run through a deep puddle at speed while the other wheels are on dry land, the steering can pull quite violently in the direction of the puddle. This pull, or a driver's overcorrection to counter it, must cause quite a few accidents or near-accidents. Another factor is the loud noise made when this happens, which may well make nervous drivers twitch.
The key to survival in these circumstances, as in all others, is to know what is happening and not to make any adjustments to steering or other controls without having a proper reason. You have to be on top of the car and show it who's boss.
Many drivers seem to be mere helpless passengers clinging to the steering wheel. Not good.
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>>But does this take into consideration the extra amount of water a wide(r) tyre has to move away
No, that's a valid point.
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My experience of counting cars in ditches when the weather is bad is that 95% of them are BMWs.
Rear wheel drive and heavy feet do not mix in the wet!
You do not need wide tyres and high power - try a Morris Minor on cross plies and you could do the same thing without trying very hard - but 25 years ago we all knew that and slowed down in the wet. These days they all drive around in their ESP cushioned worlds and don't realise that when the weather is bad the laws of physics can bite.
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There was a note on my Rover club site that you could not drive a BMW if you've been circumcised ,I have no idea if this is relevant to the thread.................
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My experience of counting cars in ditches when the weather is bad is that 95% of them are BMWs. Rear wheel drive and heavy feet do not mix in the wet!
Indeed. And remember that the vast majority of people under the age of - what? - 35 learned to drive on an FWD Car, and have progressed through the FWD Models until they have 'achieved' the status of a sports car, a BMW or a Merc.
One of my colleagues 'came into some money' and bought a 325i.
Had it a week, and almost killed himself after losing it in the wet round a bend which he had negotiated safely a thousand plus times before...
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All a wider tyre does is to chnge the *shape* of the contact patch.
Not fully true. It also increases or decreases the grip depending on surface conditions etc.
Narrower tyres in wet will give better grip versus wider tyres and conversely on dry tarmac
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There was a feature many moons ago in Autocar (or possible Motor, it was that long!) about delivering The FT around Europe from the printers in Germany (?). The vehicle in use was a Citroen CX, converted to 6 wheels to spread the weight. Anyway, it was very wet on the autobahn, so they had to slow down to avoid aquaplaning and as a result were overtaken by a 2CV, as its narrow tyes had no difficulty 'cutting' through the water.
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There was a feature many moons ago in Autocar (or possible Motor, it was that long!) about delivering The FT around Europe from the printers in Germany (?). The vehicle in use was a Citroen CX, converted to 6 wheels to spread the weight. Anyway, it was very wet on the autobahn, so they had to slow down to avoid aquaplaning and as a result were overtaken by a 2CV, as its narrow tyes had no difficulty 'cutting' through the water.
Recently when we had several inches of snow in Bedfordshire, I was able in my basic Ford Ka to negotiate the local snow covered roads with few problems. But I saw quite a few high end cars stranded, including a BMW 1 Series, a Mazda RX8 and a Mazda 3 Series. I suspect they were pedal junkies, and hence could not get grip.
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Went to Plymouth and back in a couple of days in 1962 or 3, in the middle of a very snowy winter. Driving an embarrassing hired turquoise-coloured Vauxhall Victor, a sort of dwarfish Chevrolet with column change and mercifully powerful heater.
Although rear-wheel-drive and 3 speed, the thing was only stopped once by the weather, and would show some traction and remain controllable when better cars couldn't keep going at all. A most enjoyable weekend's sideways motoring, and the big-end bearing didn't really break up until back in London.
I probably wouldn't try it now, but then with climate change I wouldn't have the chance, would I?
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