Driving in the rain with cc on: Dangerous?

[JAXRS6]

This came in an email forwarded by a friend and was a surprise to me. Not sure if it would be as bad with AWD, but does AWD really help prevent hydroplaning?
----------------------------------------------------------------------------------

I wonder how many people know about this ~
A 36 year old female had an accident several weeks ago and totaled her car. A resident of Kilgore , Texas she was traveling between Gladewater & Kilgore. It was raining, though not excessively, when her car suddenly began to hydro-plane and literally flew through the air. She was not seriously injured but very stunned at the sudden occurrence!

When she explained to the highway patrolman what had happened he told her something that every driver should know - NEVER DRIVE IN THE RAIN WITH YOUR CRUISE CONTROL ON . She thought she was being cautious by setting the cruise control and maintaining a safe consistent speed in the rain.

But the highway patrolman told her that if the cruise control is on when your car begins to hydro-plane and your tires lose contact with the pavement, your car will accelerate to a higher rate of speed making you take off like an airplane. She told the patrolman that was exactly what had occurred.

The patrolman said this warning should be listed, on the driver's seat sun-visor - NEVER USE THE CRUISE CONTROL WHEN THE PAVEMENT IS WET OR ICY, along with the airbag warning. We tell our teenagers to set the cruise control and drive a safe speed - but we don't tell them to use the cruise control only when the pavement is dry.

The only person the accident victim found, who knew this (besides the patrolman), was a man who had had a similar accident, totaled his car and sustained severe injuries.

NOTE: Some vehicles (like the Toyota Sienna Limited XLE) will not allow you to set the cruise control when the windshield wipers are on.

[DHall1]

I have a prediction.

I think you will find that an Audi or MB with VSC will override the cruise control when wheelspin is detected.

This is one of the reasons why I drive an Audi and my wife drives a MB.

End of story.

If you drive a Kia Rio or Honda Fit......your mileage may vary.

[Hy Octane]

I would think that ESP would intervene in time.

[hahnmgh63]

Per the RS6 owners manual pg. 154: "To help keep the vehicle under control, do not use the cruise control when driving on winding or slippery roads, or in heavy or varying traffic."
There is more in the manual to the warning but I think this is a NHTSA mandated warning in all U.S. automobile manuals as it is the manual for my tt and my 911 worded the same. Light wet road isn't a problem but with heavy rain or icy roads it's bad news or roads that are prone to having puddles of water.

[Shoppinit]

I have had this exact same thing happen to me, but in my Golf. It happens real quick and it's pretty scary since the diff spins one wheel much faster pulling you off to one side with a kind of gyroscope effect. A quick tap on the brakes to cancel cruise and everything is OK, but you have to react quickly.

I'd be interested to see what happens with the RS6. I won't stop using cruise in the wet, though. I'm just wary when I see puddles on road surface.

[MrBucket]

If you were to hydroplane it wouldnt speed up, if anything the wheels would spin more freely i would think and it would cut power to keep them going the same speed.

[RS6-4dr911]

If you were to hydroplane it wouldnt speed up, if anything the wheels would spin more freely i would think and it would cut power to keep them going the same speed.

True the vehicle would slow down, but it's unlikely all 4 wheels would hydroplane. Take the Golf example mentioned above. If it were one wheel that planed, the vehicle slows rapidly due to drag, the cruise detects that it needs more power to maintain speed and adds power, lots of it, the planing wheel spins faster (as you guessed), asymetric thrust pulls the car around. This all happens very quickly, faster than most drivers can react (especially a woman from Kilgore, TX). I would agree that most advanced cars with traction and stability control would catch this as suggested earlier.

[Spidercat]

Per the RS6 owners manual pg. 154: "To help keep the vehicle under control, do not use the cruise control when driving on winding or slippery roads, or in heavy or varying traffic."
There is more in the manual to the warning but I think this is a NHTSA mandated warning in all U.S. automobile manuals as it is the manual for my tt and my 911 worded the same. Light wet road isn't a problem but with heavy rain or icy roads it's bad news or roads that are prone to having puddles of water.

Good find! It probably is a standard warning, though, as you suggest.
I'm surprised that you guys use your cc. I don't even know if mine works.

[SAF]

^^Ditto^^

I've probably used CC once and never again. I prefer to be in control of my car.

[DonS]

I've seen this email once or twice from friends all over the world. The location of the accident usually changes to capture the attention of the local audience. I do believe the letter is hoax with lots of truth. Google "NEVER DRIVE IN THE RAIN WITH YOUR CRUISE CONTROL ON" and see what I mean.

I would think that a single (or pair) or disproportionally rapidly or slowly spinning tire(s) will apply spinning forces regardless of the surface. What happens when Lewis Hamilton locks his right front tire? ...he turns left without turning his steering wheel (there's got to be a better name for the device he's steering the car with - it ain't a wheel anymore) thus he is starting to spin. So, no cruise (that might accelerate) and no heavy brake applications when on rapidly changing road surfaces! And no locked brakes, blown tires...:bigeyes:

We're good with ESP and the sophisticated AWD. Hopefully the new US mandated stability programming will keep more rookies on the road. Meanwhile, let's all hope we have F1 fast hands like Shoppinit!!

[mmaturo]

^^Ditto^^

I've probably used CC once and never again. I prefer to be in control of my car.

also ditto...have never used it...nor in my old TT, X5 , Cabrio...on and on. I just prefer to always have the feet in control, especially with all the crap on the interstates today (both other drivers and objects). Perfect example on a road trip I just encountered a full size gas grill filling the entire left lane on I-64 in Kentucky when some dip head just put it in the back of a pick-up with other junk and clearly didn't tie it down. Nothing like 7' of metal laying on the ground in front of you. Got there just after it must have come off and the jerk was pulled over a quarter mile down...watched him pull back into traffic after not even backing up to remove his disaster waiting to happen.

[MarkusRS6]

also not to forget, in what condition were her tyres?

[DuckWingDuck]

also not to forget, in what condition were her tyres?

Wait, you mean people don't generally run slicks?? :lovl::lovl:

[cornishmoocher]

I have had a hydroplaning moment in th 6.

i was on the m6 motorway on my way back from grizz. It was abso;utley pissing down. I was doing maybe 50 mph in teh centre lane, luckily with nothing else on the road around me.
I felt the front go light and instantly the car did a 360.. ESP on, cruise control off.
It frightend the holy crap out of me.
The quattro is great, but when it goes, you aint stopping it.

I asked a friend who has a B5rs4 who runs 255/35 and he has said the same thing- because the tyres are so wide, it will AP very easily.

[MarkusRS6]

yeah exactly when it goes..

I was with a friend in his S3 with not so good tyres, it was raining extremely hard
we went into a tunnel, and when we got out, as soon as we hit the water, we made a 180 and then into the wall 2 times making for a full 360. Totalled the S3. There was no controlling it whatsoever. The conditions in combination with the tyres were "killer"

[Spidercat]

360 Mooch? You got lucky it wasn't a few degrees more or less and that no one else was around!
Are those GY Eagle F1's asymmetric different from the F1 GS-D3's? I've got the latter on mine and they are superb in the rain, and in the dry they are close enough to the PS2's to not make a difference to me.

So how do you like your C6 brake upgrade? BTW, can you talk to Grizz for me? I need those rotors!!! I've PM'ed him, but I don't know if he's still lurking on here or not.

[cornishmoocher]

The AP was on perreli rossos with 5 mm tread. they came off the car the next day. The f1 assys went on and its been great ever since. you have to let them warm up tho!

I will talk to grizz for you. did you see my brake test video on youtube?

[Spidercat]

No, I'll have to check it out!