Towing a caravan in cruise control.

[nav2022]

I know there are a few caravanners on here that I'd just like to warn about towing in cruise control.
There are two reasons why you shouldn't do it.
Recently in America there have been several accidents attributed to driving in cruise control. The police is some states are now advising against it. The problem is - Active braking cruise control. Some cruise control systems actually brake your car if you start going down an hill too fast and you can't disable the active breaking. The biggest cause of jack knifing is braking down hills and the trailer takes over the tow vehicle. Just be aware of active braking. So in this particular case the tow vehicle's active braking cruise control jack knifed it.
The second problem is rogue gusts of wind and the disabling of cruise control on most cars. To disable a cars cruise control in an emergency really quickly is to hit the brake pedal. Now imagine you get hit by a rogue gust of wind and you begin snaking on a motorway. You must not ever brake when this happens because it can cause a jack knife. The correct procedure is take your foot off the gas and let the engine and gearbox slow you down. This presents a problem in cruise control because you can't take your foot off the gas, you have to brake to shut the cruise off which is exactly what you shouldn't do.
Just be aware.

 

[Nitemax]

Cruise control also uses more fuel as it is constantly adjusting power to attain the target speed.

 

[TD_boy]

All good reasons for not towing a caravan and clogging up the roads

 

[Cinimod]

I must admit I’ve never liked the idea of cruise control I like the being in charge of my speed with my foot, recent speed awareness course accepted . I do now use the speed limiter though ……..dom

 

[nav2022]

All good reasons for not towing a caravan and clogging up the roads

Well at least I'm not setting fire to the street with those firebomb all electric.

 

[zakdingel]

Cruise control also uses more fuel as it is constantly adjusting power to attain the target speed.

I thought it was meant to be the opposite and save you fuel whist on a long run

 

[Mark E Smith]

Two things I will never do;- use Cruise Control or tow a Caravan.

Each to their own.

 

[nav2022]

I thought it was meant to be the opposite and save you fuel whist on a long run

Its dependant on whether you drive an auto or manual and how powerful the engine is. If you drive an auto for example and you are in cruise control on a motorway which is quite hilly such as the M1 in and around Sheffield, the auto boxes use kickdown if the revs drop below a certain point. This increases the rpm for a while and increases fuel consumption especially cars less than 150bhp diesel.
More powerful engines tend to deal with hills better and don't kickdown as much.
On manual cars in cruise control, if you start going up a steep hill in a pretty powerful car you won't have to gear down to maintain speed because there is enough torque in the engine to deal with it. On my old mondea 130bhp manual, you had to gear down to maintain speed and this is bad for fuel consumption. My Vectra auto 180bhp diesel had enough grunt and never had to kickdown, it would go anywhere in 6th. My Kuga manual at 170bhp also deals with hills quite well in cruise.

 

[Shaggy]

But all trucks have cruise although on a king pin.

 

[Fatbob 59]

I must admit I’ve never liked the idea of cruise control I like the being in charge of my speed with my foot, recent speed awareness course accepted . I do now use the speed limiter though ……..dom

Try it on a motorcycle , bloody terrifying !

 

[nav2022]

But all trucks have cruise although on a king pin.

Trucks have a completely different cruise to cars. Trucks use engine braking systems which is the best way to avoid jack knifing. Cars use active braking when your speed starts running away which is fine in a car without a trailer. The minute you put on a trailer and start braking down hills it becomes dodgy. This is why some automatic cars now have downhill assist for towing trailers. It's a button on the dash which you press when going down steep hills and its brakes the engine and gearbox.

 

[Cinimod]

Its dependant on whether you drive an auto or manual and how powerful the engine is. If you drive an auto for example and you are in cruise control on a motorway which is quite hilly such as the M1 in and around Sheffield, the auto boxes use kickdown if the revs drop below a certain point. This increases the rpm for a while and increases fuel consumption especially cars less than 150bhp diesel.
More powerful engines tend to deal with hills better and don't kickdown as much.
On manual cars in cruise control, if you start going up a steep hill in a pretty powerful car you won't have to gear down to maintain speed because there is enough torque in the engine to deal with it. On my old mondea 130bhp manual, you had to gear down to maintain speed and this is bad for fuel consumption. My Vectra auto 180bhp diesel had enough grunt and never had to kickdown, it would go anywhere in 6th. My Kuga manual at 170bhp also deals with hills quite well in cruise.

I’ve had a manual 2.0 awd diesel Kuga for the past six months and even though never towed with it, it seems to have a huge amount of grunt……dom

 

[BTB 500]

I know there are a few caravanners on here that I'd just like to warn about towing in cruise control.
There are two reasons why you shouldn't do it.
Recently in America there have been several accidents attributed to driving in cruise control. The police is some states are now advising against it. The problem is - Active braking cruise control. Some cruise control systems actually brake your car if you start going down an hill too fast and you can't disable the active breaking. The biggest cause of jack knifing is braking down hills and the trailer takes over the tow vehicle. Just be aware of active braking. So in this particular case the tow vehicle's active braking cruise control jack knifed it.
The second problem is rogue gusts of wind and the disabling of cruise control on most cars. To disable a cars cruise control in an emergency really quickly is to hit the brake pedal. Now imagine you get hit by a rogue gust of wind and you begin snaking on a motorway. You must not ever brake when this happens because it can cause a jack knife. The correct procedure is take your foot off the gas and let the engine and gearbox slow you down. This presents a problem in cruise control because you can't take your foot off the gas, you have to brake to shut the cruise off which is exactly what you shouldn't do.
Just be aware.

I've towed caravans using cruise control (with both manual and automatic gearboxes) for 24 years on all sorts of roads and in all weather conditions without ever having the slightest issue.

Caravans (and all but the smallest trailers) have 'over run' brakes that apply automatically if there's any forward load on the tow hitch - otherwise the outfit would potentially jackknife every time you braked. Having said that nobody but a lunatic would tow down a steep hill in cruise control anyway - you should engage a lower gear to avoid overheating the vehicle's brakes.

An outfit that snakes on a motorway is driving too fast, badly loaded (balanced), or too heavy. And you can cancel cruise control instantly without touching the brakes, either by dipping the clutch on a manual or using the CC controls (pushing the stalk forward or hitting 'cancel'). If you use cruise control regularly this is second nature. In fact the tiniest touch on the brake pedal will turn CC off anyway - no actual braking is needed.

All caravans have been fitted with stabilising hitches (yaw and pitch dampers) for decades, and many modern ones also have stability systems (AL-KO ATC for example) that will apply the brakes automatically if any snaking is detected.

 

[nav2022]

Towing caravans and trailers comes with its own set of difficulties. If you brake suddenly with a trailer on, there is a time gap between when the car brakes deploy and the trailer brakes deploy. That time differential is the cause of most jack knives.
When you brake the car it is almost instant but the trailer relies on the act of braking of the car first before it deploys its brakes. There is a ram system at the front of the trailer on the A frame, as the car brakes, a split second later the ram deploys and pulls the trailer brakes.
It is the time it takes to deploy the ram that is the issue. If you brake suddendly, the car is stopping but the trailer is still pushing for a split second and that causes the trailer to push the car out of shape. Trailer manufacturers have negated this somewhat with ATC systems. Automatic trailer control that electronically senses a sudden stop and deploys the trailer brakes at the same time as the car. On wagons, they have similar system but their air brakes tend to deploy at the same time as the tractor unit anyway which stops jack knives.

 

[BTB 500]

Towing caravans and trailers comes with its own set of difficulties. If you brake suddenly with a trailer on, there is a time gap between when the car brakes deploy and the trailer brakes deploy. That time differential is the cause of most jack knives.
When you brake the car it is almost instant but the trailer relies on the act of braking of the car first before it deploys its brakes. There is a ram system at the front of the trailer on the A frame, as the car brakes, a split second later the ram deploys and pulls the trailer brakes.
It is the time it takes to deploy the ram that is the issue. If you brake suddendly, the car is stopping but the trailer is still pushing for a split second and that causes the trailer to push the car out of shape. Trailer manufacturers have negated this somewhat with ATC systems. Automatic trailer control that electronically senses a sudden stop and deploys the trailer brakes at the same time as the car.

ATC detects yaw (snaking), not braking or deceleration.

Standard over-run brakes cope fine with hard braking. Of course not all trailers / caravans are roadworthy (as there's no MOT or equivalent), but that's a different issue.

 

[nav2022]

I've towed caravans using cruise control (with both manual and automatic gearboxes) for 24 years on all sorts of roads and in all weather conditions without ever having the slightest issue.

Caravans (and all but the smallest trailers) have 'over run' brakes that apply automatically if there's any forward load on the tow hitch - otherwise the outfit would potentially jackknife every time you braked. Having said that nobody but a lunatic would tow down a steep hill in cruise control anyway - you should engage a lower gear to avoid overheating the vehicle's brakes.

An outfit that snakes on a motorway is driving too fast, badly loaded (balanced), or too heavy. And you can cancel cruise control instantly without touching the brakes, either by dipping the clutch on a manual or using the CC controls (pushing the stalk forward or hitting 'cancel'). If you use cruise control regularly this is second nature. In fact the tiniest touch on the brake pedal will turn CC off anyway - no actual braking is needed.

All caravans have been fitted with stabilising hitches (yaw and pitch dampers) for decades, and many modern ones also have stability systems (AL-KO ATC for example) that will apply the brakes automatically if any snaking is detected.

So let me get this right. You are tonking down the motorway at 60mph in cruise and suddenly you get hit with a side wide from nowhere which causes snaking and you are fiddling about somewhere on the steering column to find the cruise cancel? You havn't got time, your van would be out of control before you even thought about where that cruise cancel button is.
And to say that any form of snaking is driver error is pure and utter rubbish. I've been pulling caravans for 31 years. Loaded up properly, noseweight correct on the towball, built in Alco stabilizer and you can still get caught out in certain situations. I've had coaches and motorhomes tonk by me at 85 and the suction causes some right issues. I've been in the inside lane doing 40 mph and high sided wagons have passed me doing 60 in the middle lane and sucked me all over the place. Bridges you can't see, you go over them and get hit with a rogue gust and again, its pushing you about.

 

[milek]

Try it on a motorcycle , bloody terrifying !

I couldn't go back to a bike without cruise control. On long tours it's a godsend. When I trailer the bike I use cruise on the car because the first time I trailered the bike I was up to 73mph

 

[nav2022]

I couldn't go back to a bike without cruise control. On long tours it's a godsend. When I trailer the bike I use cruise on the car because the first time I trailered the bike I was up to 73mph

Just set the max speed to 60, most cars have speed limit settings now. That's what I use for the caravan now. I set the max to 60 and just go. As soon as you hit 60 it won't rev any higher but the good thing is if I need to slow down using the engine, it does so normally letting off the gas pedal.

 

[milek]

Just set the max speed to 60, most cars have speed limit settings now. That's what I use for the caravan now. I set the max to 60 and just go. As soon as you hit 60 it won't rev any higher but the good thing is if I need to slow down using the engine, it does so normally letting off the gas pedal.

I have it and never ever thought of using it, great advice Nav, I'll give it a go.

 

[nav2022]

I have it and never ever thought of using it, great advice Nav, I'll give it a go.

Its a safer form of cruise control. If for some reason you need to get out of cruise very, very quickly such as an incident up front or your trailer is snaking, as soon as you let go of the gas pedal its out of cruise.