How many people know this could kill them?

Question

So recently I overheard that if you're driving with your cruise control on and the road is wet it can cause the tires to slip and the cars cruise control to accelerate.

It seems my grandmother had hers set at 65 on the highway and it suddenly jumped up to 90 when the tires slipped for a few seconds. Luckily it was on a straight-away and she was able to slow down, but would you believe it a cop saw her gun it and decided to pull her over. Luckily once again, he listened to what she told him and asked if she had been using the cruise control and explained what had happened. He said he only knew about it because there had been another woman who had ran herself off the road not more than 2 months earlier from the same thing.

Has anyone else ever had this happen or even know about it? Because I've used my CC all the time not knowing.

Guess this isn't so much a question as it's a "wow, I didn't know that" but it kind of freaked me out.

Answer 1

This is not ODD nor is it unusual to happen. Read the owners manual they all state NEVER TO USE THEM on wet or slippery roads

Here's how it works. ON VACUUM and when your wheel slip your engine will slow to see the change in vacuum then it will overcompensate and the CC will cause the wheels to break loose. the speedo will go to 90 or so but the car is just spinning the wheels once it hist dry pavement loss of control can happen

Answer 2

That's odd. The cruise control feature is controlled by the car's computer. When you set it for a certain speed, it calculates how much gas to give or not. If the wheels with traction slip, it should automatically stop the flow of gas or disengage, or at worst keep going at the same speed. If that actually happened, I advise you to take the car to a dealer to be checked out.

Answer 3

very goozz

Answer 4

The tires may have broke traction, but I doubt the car sped to 90.

Answer 5

So the cruise control is holding 65 and tires loose traction. The cruise would then see the speed increase due to the throttle position being more than needed to hold 65 with no load. At the same time the car would be decelerating due to the loss of traction while the speedo still reads 65. When traction is regained the vehicle would be going slower and the speedo would drop suddenly to the actual slower speed and cruise would then open throttle to get back to 65. 90 mph would never be seen. What did the cop see, was his eye good enough to notice the tires going 30mph faster than the cars actual speed of 65 or did the cop see her speeding at 90mph?

Answer 6

If it's set at 65 why would it acellerate to 90? That makes no sense.   The system is monitoring the wheel speed, if it goes above it lets off the gas, if it goes below it applies the gas.

Your grandmother is lying to avoid a ticket!

Answer 7

GRANDMA DRINKING AND DRIVING AGAIN?

Answer 8

Yep I have heard of this.

Answer 9

the car didn't accelerate to 90-the speedometer did because the wheels were just spinning. See the link for a good explaination. There are many warnings if you google"cruise control hydroplaning or aquaplaning.

Answer 10

I didn't know that, thanks for sharing.

Answer 11

Yes I know my mother was involved in an accident a few years ago that was the result of the cruise control being on when she hit a patch of black ice.  The sensor sensed that the speed had decreased and so started to accelerate by increasing rpm.  The van she was driving rolled over on the interstate, luckily no other car was hit and she although taken to the hospital was alright.  It is best to not run the Cruise control when in inclement conditions.

Answer 12

Don't know why it happens but I've heard of it happening.

Answer 13

My husband uses CC all the time, and I just hate it (without much fact behind it, just have a feeling that it takes aware attention and control as far as I'm concerned) -  I'll be interested to watch responses to this one -  good question!

Answer 14

My husband is a professional driver and he suggests never to use your cruise control in adverse weather conditions.  I always turn my cruise off while I'm driving in town to prevent it from turning on.  If anything does happen, the best thing to do is to shut your ignition off.  You won't wreck your car, I had to do this once, and you won't get killed.  Just make sure you are prepared to steer your car out of traffic without any power steering or use of power brakes.