Do Not Use Cruise Control in Rain

so I you put the cruise control ON when raining, your car instananeously transform in an airplane and accelerate to 150MPH for take off ????

 

First, it seems the author should have used "cruise control" rather than "traction control" in the thread title.

Second, there is some truth in this very poorly written anecdote. Your car is not going to take off like a rocket, but the cruise control would start applying more power as the wheels started to slip, which would only worsen the wheelslip. Look up "cruise control in rain" on www.snopes.com

 

I believe this is spam due to the urging to share it with 15 people.
I thank the OP for using the seniors font size although I have reading glasses which help a lot.
It is more important to have good tyres on your car in wet conditions. If your tyres are marginal at the start of the wet season where you live be that winter in the north or south of the tropics or summer in the tropics and places near, replace them and use quality tyres from a manufacturer you trust. I have found aquaplaning only happens with worn or poor quality tyres.

 

Any vehicle with 4 wheel speed sensors (incl. Prius) could make an excellent CC cancellation feature in software. There is a lot of incipient technology in these areas.

In the meantime I agree that wet roads require careful driving w or w/o cruise control. Tires with less than 4 mm tread depth tend to lose wet traction very quickly, and note that the wear bars are way down at 1.6 mm.

Can you read this Pat?

 

Yes thanks.

I'm still wondering about this amazing force which accelerates a car which is in a traction compromised state. The 2 times I experienced serious aquaplaning I had very low tread and was going up a hill where the water was coming down the tyre grooves in the bitumen which was overdue for resurfacing. I was in my Camry and on loosing traction the car actually stopped accelerating even though the wheel speed went up. With cruise on the cruise control would sense the increase in revolutions of the wheels and close the throttle, how can that hurt?

 

Is snoops.com similiar to snopes.com?

 

95% of the time, these chain letters are always urban legends, and the "verified by snoops.com (sic)" was a clincher. However, this is that one rare time where it is indeed true.

 

Why do people pass this rubbish down the chain. It wastes peoples' time, including the time of the person fooled into passing it along.

This particular one is mostly BS. The car will not accelerate when it loses traction, nor will it fly into the air. How could it. Let's look at this logically:

1) Flying into the air - There is nothing you can do with a normal car to make it fly into the air while driving down a flat section of road. Mashing the accelerator to the floor won't make it fly. Hitting the brakes won't make it fly. A hard turn could cause a roll-over, particularly with an SUV, but I don't really consider that flying. To fly, the car needs to hit something, jump a ramp, or go off a cliff.

2) Sudden acceleration from losing traction - Let's say your car loses traction on ice. What happens when you mash down the gas pedal? The engine races, but your car doesn't go any faster. That's what happens with older cruise control. The car loses traction and starts to slow down, so the cruise control commands more gas. The additional gas makes the tires spin, but the car continues to slow. In response, the cruise control tries harder with more gas. The engine will race, but not the car. Note that this works only if the cruise control speed feedback comes from wheels other than the driven ones.

This cruise control problem is in reality a potential control risk. With an older design, the car can lose traction and the cruise control can cause the driving wheels to spin, exacerbating the problem. A quick tap on the brake pedal or CC button will fix the problem, but that assumes the driver isn't frozen by fear.

So there is a grain of truth behind this urban legend. You need to be extra vigilant driving in adverse conditions, and you may want to disengage cruise control to avoid being surprised. On the other hand, with a modern car like the Prius, the control system is smart enough to avoid this problem. Traction control, and VSC (if you have it), will modulate the power output to help avoid these loss of traction situations.

Tom

 

Every cruise control design I have heard of uses the speedometer take-off which is from the transmission (i.e. the driven wheels).

The engine will not speed-up or race if traction is lost, it will just maintain the speed of the wheels as before.

kevin

 

Exactly, and that is true even with the older designs. Maintaining the speed of the wheels can still cause a loss of traction as the vehicle slows down, but it's no worse than pulling your foot off of the gas on slippery roads.

Mostly this is a problem because of surprise. When a car does something unexpected, people tend to freak out. That's why you need to be familiar with your car and how it works.

Tom

 

Assuming a 5 knot headwind, how fast would you need to be traveling in a Lincoln Town Car before you "take off like an airplane"?

If I find one for really cheap someday, I might want to test this out for myself. :madgrin:

 

There was a certain Le Mans racer that could take off. The landings weren't very smooth, though. That's Toyota's GT1 in front.
[ame="http://video.google.com/videoplay?docid=-1252498464502394753"]1999 Le Mans[/ame]

 

a car with just CC will maybe to this
but the prius will automaticly drop out off CC when the VCS kicks in.

 

Do you think the cruise control was on? It was raining. Would a Lincoln Town Car take off at that speed?

 

I don't think a Lincoln Town Car would ever get to that speed. Maybe if it was dropped from an airplane....

 

Well, the snopes article said that the woman was driving a Lincoln Town Car......I never would have guessed that they could generate much lift at any speed, but she said it "took off like an airplane". I would think that even if you had an airplane wing installed, it would still be difficult to get it airborne, but I'm not an aeronautical engineer.

 

With or without JATO bottles?

Tom

 

Whatever it takes to get it airborne.