Is it wise to tow up to 100% of kerb weight?

[oldagetraveller1]

My current tow car is a 2013 Peugeot 5008 2.0 litre diesel auto.
Kerb weight is difficult to identify accurately, but I think it's around 1620 kilos.Max weight towable is fixed by Peugeot at 1500 kilos.
I'm very satisfied with it and it tows my current van of 1300 kilos without difficulty.
But, I would like to change the van for one of 1500 kilos and, preferably keep the same car. This would mean a ratio at 94%
I have been towing for 30 years but I would like to hear from other contributors who have experience of towing so near to the limit.
Also, would fitting ATC help?

 

[pitpony]

I have just changed my car for that very reason, I came in at 93.5%, I was changing the car anyway next year but brought it forward because of not wanting to be towing at that weight, personally I can't see a problem if the outfit is legal and you are comfortable towing at 94%, the 85% guide is a recommendation and that is what it is a a recommendation,

 

[colin-yorkshire]

My current tow car is a 2013 Peugeot 5008 2.0 litre diesel auto.
Kerb weight is difficult to identify accurately, but I think it's around 1620 kilos.Max weight towable is fixed by Peugeot at 1500 kilos.
I'm very satisfied with it and it tows my current van of 1300 kilos without difficulty.
But, I would like to change the van for one of 1500 kilos and, preferably keep the same car. This would mean a ratio at 94%
I have been towing for 30 years but I would like to hear from other contributors who have experience of towing so near to the limit.
Also, would fitting ATC help?

Nose weight and towing ratios are probably the most often questions asked, and also probably the most disputed topics you can get answers to because it is an area of vastly differing ideas and beliefs. the chances are no two answers will agree.
some will say No and stick to the idea that because someone came up with a 85% figure 50 years ago when cars had drum brakes and carburettors, it must be the right thing to do, as no one has come up with a better figure, and all the major organisations still recommend it.

others will say it doesn't matter as technology has moved on, and if a vehicle manufacturer says it will tow above 100% then it will.

I personally would not agree with either view as there are so many other variables to take into account, it is impossible to predict how a unit will behave under tow. until you try it, it is not just the assumed maximum weight of the trailer set against the minimum weight of the tow car, as a figure in it's self that is important, but all the other factors that come into play, as a caravanner with 30 years experience you know this already.

if it is any help in the last 50 years, I have towed trailers and caravans ranging form 50% to 120% with differing vehicles from 1000 KG to 6 Tons. each and every tow was different some good some bad and none could be attributed to weight alone,

just remember that a caravan is not an ideal type of trailer to tow due to it's design it's not all about the weight and tow ratio.

 

[Woodentop]

Didn't I read somewhere a long long time ago that if the ratio is 100% or greater the train is limited to 50mph on all roads?

 

[Jaydug]

From 1991 till 1998 I used one of the first mass-market turbo diesel cars available to tow my caravan. The turbo engine was amazingly capable but the low kerb weight of the car meant that I was towing at almost 100% weight ratio. Hills were taken in its stride but driving generally was a far from a relaxing experience. So often I felt that instability was just waiting to happen.

 

[saint-spoon]

Didn't I read somewhere a long long time ago that if the ratio is 100% or greater the train is limited to 50mph on all roads?

I'm not sure if the law has changed but certainly it was the case back when I used to go caravanning with my parents. everyone used to have a sticker on the back of their vans stating the maximum speed that it could go.

 

[Dustydog]

In addition to Colin's wise words may I add that apart from correct nose load and being certain your car manufacturers maximum tow weight is not exceeded, correct loading is imo crucial to a safe tow.
I think you know the principle of keeping things low and over the axle where possible.
ATC will not help in the way suggested. It was not designed to make a poorly loaded unit safe.
And yes I subject to my own criteria will go above 85% a blind have done so in past years.

 

[Raywood]

The 85% figure is a recommendation for newcomers and the more experienced can exceed it although the firm recommendation is do not go over 100%. There is as Colin says no right and wrong answer to this but the 85% figure is certainly not 50 years old. What is undeniable is that the heavier the tow car the better provided it has the power to match.
Essentially you need weight to control the caravan and too heavy a trailer can end up with the tail wagging the dog. Because different cars and caravans have different towing characteristics there is no easy answer but personally I would not be happy going much over 90%.
The manufacturers towing limit is the weight it can restart on a 12% slope and has nothing to do with safety. The problem they also have is that towing a low flat trailer weighing more than the car at low speed may be safe but a lighter high sided caravan has large flat sides that are more susceptible to side winds and passing traffic.
94% is about my top limit of possible and if you are able to change the car if it proves too high then I would go for it. If you could not change the car if needed then I would probably not.

 

[chrisn7]

I used to tow a 1500kg van with my old Saab 9000 turbo, which had a ton of power but weighed in 1440 Kg. The car itself was stated to be able to tow 1800Kg max. We did not have any mishaps, but you are conscious of reduced margins, as the van was affected by the wash from HGVs, even with the stabiliser.
So, yes you can do it, with caution, but if there is any tendency to snake, then change the car

 

[colin-yorkshire]

The 85% figure is a recommendation for newcomers and the more experienced can exceed it although the firm recommendation is do not go over 100%. There is as Colin says no right and wrong answer to this but the 85% figure is certainly not 50 years old.

hi Ray, if anyone has a definable date and origin of the 85% recommendation. and a place where the information can be seen I would be very interested. All I know is when starting out on this great hobby in the late sixties. you know that time before the EU that no-one wants to remember. when we used [hundredweights and tons] I had a Cortina that weighed just about a ton. when looking for a starter van, all the info I could get suggested that the maximum weight I should tow with it was 16cwt. which apparently by coincidence is just about 85%.

 

[ProfJohnL]

Is it wise to tow at 100% of kerbweight? Generally I would say avoid it if possible. But its not a black and white issue. I have long advocated that drivers should aim to keep the weight of any trailer as small as possible, but I have deliberately refrained from giving a specific figure, because there are so many variables which is also why the oft misused 85% guidance is unreliable.

 

[oldagetraveller1]

Thanks to everyone who has contributed to this topic.
I think I'll try using my existing towcar and have a back-up plan to change it if I feel an any way uncomfortable..

 

[martindf3]

Didn't I read somewhere a long long time ago that if the ratio is 100% or greater the train is limited to 50mph on all roads?

Quickly .. caravan and trailer speed limit on single carriageway is 50mph . on dual carriageway with derestricted sign ,its still 50mph over 3.05 tons combined UNLADEN weight !!!!!
under 3.05 tons combined unladen weight its 60 mph .. nothing to do with 100% advisory .
We are all obsessed with maximum permissible weights, speed limits are to do with unladen weights fortunately

 

[ProfJohnL]

Didn't I read somewhere a long long time ago that if the ratio is 100% or greater the train is limited to 50mph on all roads?

Quickly .. caravan and trailer speed limit on single carriageway is 50mph . on dual carriageway with derestricted sign ,its still 50mph over 3.05 tons combined UNLADEN weight !!!!!
under 3.05 tons combined unladen weight its 60 mph .. nothing to do with 100% advisory .
We are all obsessed with maximum permissible weights, speed limits are to do with unladen weights fortunately

I have not been able to verify the information Martin has supplied. I am looking into this, but so far the unladen weight threshold of 3.05T seems to relate to Motorhomes or motor caravans but not cars and caravans that fall within the Cat B or BE licenses restrictions.

 

[Raywood]

According to the CC the towing speed on dual carriageways and motorways is 60 mph for cars and the train weight is irrelevant.

 

[Dustydog]

The Highway Code confirms Ray's post

 

[Sproket]

Have a look here at speed limits for towing a caravan. ...

 

[ProfJohnL]

Hello Sprocket,

We know from past experience that we cannot implicitly trust the Government portal to accurately portray the the underlying act or regulation.

I am currently trying to get hold of the official acts that form the law in this area. Its not easy finding the most recent document.

 

[JonnyG]

hi prof.. although given sprocket.s link is what has been taught, and repeated by every official test one can find,and has been applied by anyone with the offical authority to act upon it ,one has to assume it is correct ... caravan speed limits are 50 mph on A roads and 60 mph on dual carriageways and motorways unless otherwise stated by a road sign.. and those limits that apply to 3.05t above or below are for motor caravans and motor homes, not towed caravans..

 

[ProfJohnL]

hi prof.. although given sprocket.s link is what has been taught, and repeated by every official test one can find,and has been applied by anyone with the offical authority to act upon it ,one has to assume it is correct ... caravan speed limits are 50 mph on A roads and 60 mph on dual carriageways and motorways unless otherwise stated by a road sign.. and those limits that apply to 3.05t above or below are for motor caravans and motor homes, not towed caravans..

Hello Jonny.
Past experience of comparing the Gov't portal with the underlying Acts of Parliament has shown me not to accept at face value almost anything to do with towing. From just the odd (but important word) missed from a definition to completely rewritten definitions which when securitized give and entirely wrong take on a topic, make such reliance on the portal difficult to accept.

It would be exceedingly annoying or worse for any one who relied on the definitions given in the portal to them find themselves the wrong side of the law, It wold be interesting to find out if reliance on the portal definitions was accepted as mitigating circumstances. However I doubt it wold be as Ignorance of the law is not an excuse.

However, In this instance I believe the portal may have it right, but I still want to check. I also concluded that the 3.05T threshold did not apply to cars and caravans subject to Cat B or BE license restrictions.

 

[JTQ]

Returning to the OP's question; IMO the weight ratio that it is "safe" to use is dictated by other characteristics of the tow vehicle, and for that matter the towed vehicle. Some combinations at 85% are going to be worse than others at above 85%, but as a trend the lower the ratio the better the stability, all other things being equal

So lets look at the OPs tow car the 2013 Peugeot 5008 2.0 litre diesel auto.
Whilst I have never towed with one a visual look at it indicates a very short overhang, a long wheel base and a modern vehicle designed as a people mover. All three of these feature points strongly hinting at it making a very stable towing vehicle. The short overhang reducing the leverage, the long wheel base and robust rear end needed for the people mover role both leading to high lateral stiffness.

With the specific vehicle in question I would have no reservations in towing with it at the level stated by the OP, together with his quoted experience of towing.

I do feel that a blanket 85% guidance figure is far too crude a tool, not soundly based on the science involved. I suspect if the caravan industry intends to survive the inevitable trend to lighter towing vehicles, then some more enlightened research and classification of towing ability is going to be required, and quite soon. Something like the NCC's battery classification A, B & C against differing mass ratios.

 

[ProfJohnL]

Hi JTQ,

Excellent comment, well argued reasoning about the OPs potential outfit.

I totally agree about the need for a revised guidance model, and I am still trying to devise a more reliable matching scheme. The big problem is the dynamics of a caravan can be so readily affected by how it's loaded. A well loaded big caravan can be much easier to tow than a poorly loaded small one. We also cannot dial in the biggest variable if all - the driver.p

Because there are too many uncontrolled variables (driver, road and weather conditions etc) it will be impossible and unsound to suggest any outfit combination is SAFE. So it's more a question of identifying unsuitable combinations, but based on technical grounds rather than the ad-hoc unscientific current notional towing ratio.

 

[oldagetraveller1]

It's been very interesting reading all the posts on this topic.
Can I return to the question of the effectiveness of ATC?
Assuming a ratio of 95-100% (Van/towcar), an experienced caravanner,and a correctly loaded van, there are still situations where external factors intervene. For instance, a strong cross wind or being passed at speed by a coach.
Often, this results in a slight 'sway' which is completely controllable.
My question is, does ATC eliminate this?

 

[colin-yorkshire]

no, it won't, it may reduce it but not eliminate it, the ATC and similar systems, use sensors to detect sideways movement dependant on the amount of movement it operates the brake of the van on the opposite side which corrects the movement . given that this takes time and may need several corrections either side before the movement is stopped and the fact that trailer brakes are not that efficient [similar to a car hand brake] only on big movements would you feel any difference. a passing coach, would not cause the system to trigger a big response just a slight correction, if the van is loaded correctly the effect would be minimal any way.
people who know more about these systems than I often say ATC will not correct a badly used outfit, and is no guarantee the unit will behave any better that it would. normally.

 

[ProfJohnL]

....
people who know more about these systems than I often say ATC will not correct a badly used outfit, and is no guarantee the unit will behave any better that it would. normally.

Hello Colin,

Perhaps I can clarify the issue slightly differently.

ATC is not designed to be used as system to make a badly matched outfit derivable. It's designed to be a back up safety device just like car seat belts where no one should find a seat belt necessary to make a car drivable, but its there if you get the driving bit wrong.