The internet has made available an entire world of easily-accessible information… and misinformation. Type into Google, ‘why you shouldn’t use cruise control in the rain’, and you’ll get a raft of different views. So, right now, for once and for all, we’re going to settle this issue with those things that no one seems to care about anymore – FACTS.
Don’t use cruise control in the rain (but not for the reasons you might think)
The short answer is no, it’s best not to use cruise control when it’s raining – but not for the reasons you might read on the internet. The myth is that cruise control can make your car suddenly speed up if it begins to aquaplane. This is impossible, and here’s why.
How does cruise control work?
To debunk this myth, we need to take a quick look at how cruise control works. These days, software is used to tell the cruise control system when the set speed has been reached and when the car is slowing down. This software also tells the system when the brake has been used so it doesn’t fight the driver, disengaging cruise control instead.
The software tracks the speed of your car through the driveshaft, which essentially means its monitoring the powered tyres’ revolutions.
Cruise control and aquaplaning
Aquaplaning occurs when the tread on our tyres can no longer disperse water adequately. A layer of water then builds between the rubber and the road, essentially lifting the car off the ground and causing it to slide over water without any grip.
It’s been mistakenly reported time and again that cruise control can actually speed your car up when it aquaplanes. Not the case. When we aquaplane, the tyres lose traction and start spinning faster. Considering cruise control tracks the car’s speed through the tyre’s revolutions, it will actually think we’ve sped up when we aquaplane and ease back on the throttle, attempting to slow the car down.
Why do we aquaplane?
For two reasons:
- The tread on our tyres is too worn.
- We hit a patch of water too fast for the tread to disperse it quickly enough.
The speed at which we hit water is what matters. Whether cruise control is on is irrelevant.
What should I do when aquaplaning?
When you feel your car aquaplaning, brake slowly and steadily. Nearly every car on the road these days has ABS, which will stop the wheels from locking up (which was a problem in the past). If the car begins to turn as it slides, turn the steering wheel in the same direction. When you regain traction, slowly bring the car back in line with the lane.
When is it appropriate to use cruise control?
Cruise control is best used on relatively straight stretches of road when conditions are good. Cruise control does not have the ability to detect conditions or approaching hazards; it won’t slow down automatically for a corner or braking cars. If the road you’re on has corners with recommended speeds lower than the enforced speed limit, it’s best not to use cruise control.
Similarly, if it’s raining heavily and the enforced speed limit feels unsafe, either set cruise control at a lower speed or take it off altogether. The fact of the matter is, when we engage cruise control, we’re slightly less alert, which is why it’s best practice to switch it off when conditions aren’t optimum.
So, while cruise control won’t cause you to speed up when you aquaplane, we still do not recommend its use during inclement weather.
Get your tyres checked
To avoid aquaplaning, slow down and make sure your tyres have adequate tread. We talk about tread all the time, and for good reason.
Your tyres only have four hand-print-sized patches of rubber to keep you on the road. If the tread is too worn, it cannot adequately funnel water away – and you’ll lose control of the car. The most difficult part about checking tread depth is remembering to and then getting down on your knees. The rest is easy, which you can read about in our blog on checking tread depth.
If you think your tyres are worn, please drop into Eastern Tyre Centre as soon as you can. We’ll do a thorough assessment and make some recommendations. Whatever the result, rest assured you’ll be driving away on tyres fit for purpose.