This is certainly one of “those” discussions on any caravanning forum… with a wide range of, often heated, opinions on the question. My response? Well, it all depends… While it might seem like I am sitting on the fence, there are some times you can use it… and other times when you most certainly should NOT!
But let’s first understand what cruise control is, and how it works.
According to Wikipedia:
“Cruise control is a system that automatically controls the speed of a motor vehicle. The system is a servomechanism that takes over the throttle of the car to maintain a steady speed as set by the driver.”
So, the idea is simple… set your cruise control at 100kph, and the throttle will try to maintain that speed.
When going UP hill, your speed drops. And at a certain point (which varies according to the vehicle, the load, and the speed set) the throttle will apply more pressure, and possibly engage a lower gear, in an effort to maintain the speed selected.
When going DOWN hill… normally vehicles speed up. Depending on the type of cruise control fitted to your vehicle, it MAY attempt to slow the vehicle to maintain the speed set by engaging a lower gear or by braking (in more modern vehicles, this is likely). Often however, your speed can increase because the idling motor is not being used as a brake on the downhill run. Thanks gravity!
Usually, cruise control is turned OFF by either:
* applying the brakes to slow the vehicle, and/or
* pressing the “Cancel/Off” function on the cruise control lever.
It would then need to be “Reset” (or Resumed) by the driver, once the desired speed is again achieved.
When CAN You Use Cruise Control?
Cruise control is suited for driving at a steady speed without constant stopping. You would normally use it in on a (reasonably flat) motorway or highway, rather than on a street with frequent traffic lights, where there is lots of traffic, in windy, hilly terrain, or where road/weather conditions are hazardous.
Since its main purpose is to maintain a set speed then when it is set at, or slightly under, the posted speed limit, you should be able to avoid any “accidental” speeding tickets from any small lapses in concentration! Please remember however, that a cruise control may go over its setting on a downhill steep enough to accelerate with an idling engine. Remember also that you can set speed warnings on most modern GPS systems now too 🙂
On the open road, when the terrain is fairly flat, using cruise control to maintain a set speed can also result in a small improvement in fuel economy (continual acceleration and braking uses more fuel than maintaining a set speed). That not only helps reduce emissions, but saves your wallet a little bit as well! If however the terrain is hilly, constant downshifts might actually use MORE fuel, so be aware of when the cruise control is engaging and cancel as needed.
It can also help to reduce driver fatigue on long trips since you don’t have to keep concentrating on your speed and throttle setting all the time… which can lead to a more comfortable and relaxed journey.
You need to be aware of a few things that can go wrong as a result of using cruise control.
Using cruise control can take your mind “off the road”… such that IF something does go wrong, you may not be able to respond as swiftly and effectively to the emergency situation. If cruise control is on and the road conditions suddenly change or worsen, the potential for losing control of your vehicle becomes greater.
For example… when cornering… the car will automatically enter a corner at the cruise speed set. If this is too fast for the corner, any subsequent braking to reduce speed could affect the stability of the vehicle, and possible loss of control.
Wet weather – bad visibility and bad driving conditions – requires the full attention of the driver, so please de-activate cruise control in such weather conditions. Wet roads significantly affect the grip of your tyres, so any corrective actions needed are more difficult to judge.
Sudden changes in the road surface – i.e. sealed to dirt – could result in loss of control with the driver unable to disengage the cruise control fast enough to respond to the situation. Or, at the very least, scare the @$@!% out of you 🙂
Since they require little attention from the driver, speed control systems can encourage “highway hypnosis”. Some accidents have been reported where drivers weren’t paying attention and drove off a curve or into other cars because of the constant speed. There’s also the one about the driver who stepped back into his motorhome to make a cup of coffee…
Cruise control should NEVER be used by a driver who is feeling tired. Your reaction times could be too slow to take any corrective action needed.
Remember that when going UPhill, as your speed decreases, cruise control will either increase throttle pressure and/or change down a gear, in an attempt to maintain the set speed.
If you want to look after your engine and gearbox, it might be better to NOT let it change back and rev the guts out of the motor, chewing up even more fuel than you would like! Practice “cancelling” cruise control as the speed drops, and take over manual control of the accelerator until you reach the crest of the hill.
Similarly, when coming DOWNhill… by the time your cruise control realises it no longer needs to be applying power to the motor to get over the hill, you’re probably already exceeding the set speed as you start down the other side. If your cruise control doesn’t apply the brake or change gear automatically, it would be best if you again “cancel” it and resume manual control, and possibly even changing DOWN a gear to have a controlled descent!
When Towing? Well… ALL of the “problems” mentioned above will be compounded when you’ve got a couple of tonnes behind your vehicle pushing you along the road!
Reaction times are slower… stopping times and distances etc increased… and the cruise control could really be working overtime the second any slight hill is detected.
If you car has cruise control, it might even pay to read the owner’s manual and find out what the manufacturer says about using it 🙂
Should/Can you use Cruise Control while Towing?
It all depends on:
- the tow vehicles power and torque, and how well it handles hills,
- the weight/stability of the trailer/van being towed,
- the road conditions (sealed, dirt, flat, windy, hilly etc),
- the traffic conditions (light, heavy, traffic lights, city, country etc),
- the weather conditions (rain, wind, night etc)
Cruise control is NOT made for all road conditions, especially when towing!
It would probably be best to confine the use of cruise control to the flat open highway in good weather, and “drive” the tug normally as you should anywhere else – i.e. in heavy traffic, city driving, slippery roads, winding roads, bad weather, unsealed roads, etc.
Try it out with your vehicle/trailer combo and see if you like using it.
It’s not so much about cruise control, as “Who’s in Control?” 🙂