85% debate continuation

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May 7, 2012
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I appreciate that the manufacturers may upgrade other components when giving a vehicle a higher towing, limit but that does not cure the major problem we have with caravans, the large flat sides. While good suspension and handling characteristics do help, at the end of the day there is no substitution for weight when a car has to keep control of a wagging caravan. Caravans are more susceptible to side windows than most things being towed and that is not something any car designer can overcome, although they can help.
 

JTQ

May 7, 2005
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I appreciate that the manufacturers may upgrade other components when giving a vehicle a higher towing, limit but that does not cure the major problem we have with caravans, the large flat sides. While good suspension and handling characteristics do help, at the end of the day there is no substitution for weight when a car has to keep control of a wagging caravan. Caravans are more susceptible to side windows than most things being towed and that is not something any car designer can overcome, although they can help.

I know where you are coming from and half agree, but weight is IMO not as fundamental as implied.
You can have a heavy kerb weight pick up running light with all its mass up front, being a pick up it will have quite an overhang. That lightly loaded rear suspension with a great distance to the vehicle's centre of gravity, make its mass far less of a stabilising factor than if the mass was further aft. With the pick up the CoG and roll centre are also typically going to be high, doing towing a caravan no favours.
There is so much about the vehicle other than its mass, and there is where any mass is, that are important.
The 85% mass ratio guidance is technically a rather "dumb" criteria, arguably better than nothing, but still nothing like as good as actually considering the vehicle's specific attributes for towing, of which actual mass is but one.
 
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Thanks Lutz-great that someone on here work(s/ed) for a manufacturer and this is exactly my thinking. As for novices towing-whole different ball game and another thread. I'd have thought size of van-width and length would be a bigger limiting factor rather than weight if the rig is stable. Our first two caravans weren't much different in weight but our Pegasus much longer than our Avondale ARgente(cracking van) and it is the length and width of our Bucanneer that I think most about! A lot about!
 
Mar 14, 2005
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IMO manufacturers published towing limits are a joke that only serve to confuse your average motorist who wants to use his vehicle for towing.
They only have relevance where the manufacturer forbids towing for a particular model or specifies a towed weight limit well below the towing vehicle's own weight.

The majority of published towing weight limits are widely optimistic and have no place in the real world.
I find it amazing that vehicle manufacturers have not agreed a more real world system of assessing towing vehicle capabilities.......after all they can rank vehicles for crash survival!

I see the 85% of kerbweight guidance as an attempt to put forward a simple method of keeping a sensible weight balance in a towing outfit.

...........and yes there are many other factors involved in safe towing.
Hello Gaffer,

I don't think the car manufacturers are entirely to blame for the towed weight figures they produce. The towed weight figure is the result of a set of prescribed tests or calculation on specific criteria and is used as part of the process for type approval.

While the tests do include repeated pull away's on a 12% incline, but it is not just limited to that as Lutz has pointed out.

The results are at least based on evidence from testing.
 
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Mar 27, 2011
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I find this discussion to be of great interest with a number of excellent views and fairly technical but not to the point of needing a degree to understand, that’s a refreshing change as often this topic along with nose load develops almost into an argument so it’s great, for my penny’s worth as to this topic, I don’t weigh my caravan full or empty, I’m aware of its manufactures weight plate and I rightly or wrongly assume it’s near enough for me, I spread the weight of what I put in when travelling and load the towcar to take as much off the van as is prudent and I take as little as I can get her in doors to leave at home, I then, and this is the really important part, I drive extremely carefully, giving plenty of room in front and sticking to the speed limits as a maximum and most of the time under the limit, I look ahead and look for idiots ahead and behind, if the idiots are behind I slow down even more and let them pass sooner rather than later, anticipating the roads and traffic ahead is so important, I drive around 35k miles annually so I do this day in day out, if more drivers did this whether towing or solo there would be far less accidents in my opinion.

BP
 
Jan 31, 2018
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Totally agree with everything you say Bee; my philosophy. As you am loving the opportunity to discuss this issue which has been important to me ever since our neighbour decided not to buy a Coachman as it was just over the 85% 'rule' as he told me. Seemed sad at the time but he has sensibly gradually 'moved upward ' and become more adventurous. Cost him a caravan change though. People are being put off by thinking the 85% is a rule and law ; no it's just sensible if you have never towed. Cheaper may be to get some towing lessons or is that not enough? I love driving and have towed a tiny trailer and done my Minibus test, but I was NOT a confident tower initially but took my time,
 
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Hello Jezzer,

One of the reasons the 85% guidance became so misused and quoted is because to many people have kept on incorrectly using it.

The misquote seems to be easy to remember, so continually seeing in print reinforces the misconceptions around it. Through this process it has grown and become so important in people's minds, it has spawned the myths about its importance and legal status.

To try and break this spiraling cycle of self perpetuating importance , I have encouraged people to only refer to it as 85% guidance or advice to the exclusion of anything else.
 
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May 7, 2012
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I do tend to agree the recommendation is often wrongly cited as a rule. I do try to point out it is only a recommendation if trying to help people on weights, but stress at the same time for a beginner it is better to err on the side of caution, so do try to get as near as you can, as there is no other alternative method available for them. Towing performance of cars has improved over the years so perhaps 90% might now be a better figure but it is all guesswork.
All combinations do vary so a one size fits all cannot be produced but you have to give newcomers some guidance.
As Lutz says pickups can suffer from a very light backend and a higher centre of gravity, which in theory can put them at a disadvantage on paper in technical terms despite them usually having far higher kerbweights. In practice I think the additional weight will normally cancel out the other problems but it does show the problems involved here in giving advice.
 
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I do tend to agree the recommendation is often wrongly cited as a rule. ...

Ahggg,

Sorry Ray,

This is an example exactly what I have been trying to eradicate. :coldsweat: Using the "r..." word in any relation to towing ratio matter (including trying to denounce it) continues to reinforce the misuse of it.
 
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Prof,
Have you ever contacted any of the caravan industry organisations like the NCC with your findings and what you think of the 85% guide line,
 
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Parksy

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Ahggg,

Sorry Ray,

This is an example exactly what I have been trying to eradicate. :coldsweat: Using the "r..." word in any relation to towing ratio matter (including trying to denounce it) continues to reinforce the misuse of it.
Please don't try to police the grammar used by other forum members.
If you'd care to check on forum etiquette, you'll find that this is mentioned specifically.
 
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I get your drift Parksy-and this is a great forum because of the hard work of moderators and comments like this-makes things much nicer than some forums. However I don't think Prof was trying to police grammar-and hopefully the poster wouldn't take offence , but was just trying to make the point that the word rule is used with the 85% ADVICE by far too many people that others look 'up' to for guidance. It is sad as my neighbour wasted a fair amount of money because he was refused a caravan at main dealer (dealer's loss though and noble but incorrect) when he got the make and model of Yeti wrong (though that did my neighbour a favour eventually as he did get a van he preferred). We also had a sleepless night because of this 85% thing as we visited a dealer with 2 branches and had 2 of their salesmen fighting over a sale of 2 caravans of the same layout, one being slightly bigger/heavier than the other, with the result that one had a real go at me for driving an outfit he deemed unsafe. Had we not had the courage of our own conviction we'd have bought a caravan that was far too small for what we needed the upgrade for. The managing director rang us to apologise and we had a lovely conversation with him and he checked our outfit-deeming it ok , as we subsequently found through many years of happy towing experience. We also received a small discount as apology but I wonder how many decisions have been swayed by the 85% advice and how much extra money spent on car upgrades that may not have been necessary.

We simply decided we'd try it drive slowly if we felt there were issues and then upgrade the car. We instantly realised that our Dacia Duster towed our Pegasus Verona with ease making a mockery of 85% kerbweight-we were at around 116%.
 
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Prof,
Have you ever contacted any of the caravan industry organisations like the NCC with your findings and what you think of the 85% guide line,

If you had followed this or any of the other threads on the subject I think you will see I have tried to establish who the source or who has has ownership of the advice through industry contacts that I have. - Without success. that was the major finding of my research.

My thoughts about the subject are quite well known, and if the appropriate body felt they could defend the advice they could easily have made contact to do so.

There are several apocryphal stories of why and how the advice was produced but no one with any authority will confirm which if any is correct.

The silence I get from industry quarters is incredibly frustrating, and leads to the suspicion that they either don't know themselves or their too embarrassed to admit it, or maybe have been advised not to admit liability.

The DVSA wont comment on it apart from to say its not part of any driver or vehicle based regulations.
 
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If you had followed this or any of the other threads on the subject I think you will see I have tried to establish who the source or who has has ownership of the advice through industry contacts that I have. - Without success. that was the major finding of my research.

My thoughts about the subject are quite well known, and if the appropriate body felt they could defend the advice they could easily have made contact to do so.

There are several apocryphal stories of why and how the advice was produced but no one with any authority will confirm which if any is correct.

The silence I get from industry quarters is incredibly frustrating, and leads to the suspicion that they either don't know themselves or their too embarrassed to admit it, or maybe have been advised not to admit liability.

The DVSA wont comment on it apart from to say its not part of any driver or vehicle based regulations.
[/QUO

Prof,
I did not know you had gone to those extremes to get to the bottom of various issues including the 85% thingy, mentioning the DVSA I think they should be responsible for caravan regulations on this issue they are very good at jumping on the backs of LGV dri ers, if I get pulled later this year when I travel to Dorset I will be ready for them,
 
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I know where you are coming from and half agree, but weight is IMO not as fundamental as implied.
You can have a heavy kerb weight pick up running light with all its mass up front, being a pick up it will have quite an overhang. That lightly loaded rear suspension with a great distance to the vehicle's centre of gravity, make its mass far less of a stabilising factor than if the mass was further aft. With the pick up the CoG and roll centre are also typically going to be high, doing towing a caravan no favours.
There is so much about the vehicle other than its mass, and there is where any mass is, that are important.
The 85% mass ratio guidance is technically a rather "dumb" criteria, arguably better than nothing, but still nothing like as good as actually considering the vehicle's specific attributes for towing, of which actual mass is but one.


We have a Bucanneer Cruiser and upgraded our Dacia duster to a Nissan Navarra NTekna deeming it the best car for our purpose ie a very messy dog who demands the front seat, easy to clean and robust dash, but lots of kit-leather heated electric seats, cruise and most importantly for this best-a speed limiter-so refined and far too easy to break the limit given the 190bhp and huge torque figures.

Our findings completely contradict the above- it is absloutely frightening how easily the Nav tows the Buc-200okg of caravan. 6th is a bit high so we use 5th on single carriage roads and 6th on motorways but the caravan is rock solid even when over taking lorries or being overtaken by those National Buses that fly up our roads. Good job we have cruise because you simply forget the caravan is behind us till I look-and 60mph limit is far too easily exceeded-hence the judicial use of the limiter and cruise. No evidence as yet of any worries re the lighter rear end some people seem to think they suffer from-not sure where that comes from but our experience is that these 'cars' are supreme towers and i am not surprised you see more and more of them on the roads-where else can you get voice control satnav, cruise speed limit heated electric leather seats bluetooth 190bhp , 3500kg towing and 1000kg load capacity-and if you buy a truck back(canpy) space for all your kit plus the family bikes, (we took the father in laws electric buggy and it would have gone in there without disassembly etc etc etc. It has 5 seats, isofix and the sort of rear you aren't worried about when getting rid of the garden waste at the local trip-one car for every need-absolutely. As far as we can see its only disadvantage is its length -you do hang over some car park spaces . All for 26k if you aren't in business. Oh and 36-38mpg around and about, and 22-24mpg so far towing. I am not in any way allied to Nissan, and would recommend a truck to anyone-not just a Nissan-its 4wd system is rather rudimentary when compared to teh Amarok-we just couldn't afford an Amarok or the fuel bills of the 6 cylinder!!!!

I should add that once we had bought it I started reading round the subject and was very rattled by
a) it is a commercial vehicle-some manuafacturers bar their use. From my findings this now is only Lunar-someone out there may correct me. Our dealer actually recommended the car very highly and use one themselves!
b) reports of the new suspension being too high and the caravan therefore towing at a weird angle-had to suck and see that one-wrong-it is perfectly level when hitched up
c) the worry that Nissan couldn't tell me if the tow ball was Alko friendly or not-simple check with a tape measure after consulting the Alko website proved it to be fine!
 
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May 7, 2012
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I think the answer is simply that while the laws of physics say that a pick up is not ideal the sheer weight of the Nav simply outweighs this. Lighter pickups mjight be a different proposition.
 
Mar 14, 2005
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I have never towed with pickup truck, but when I vested Canada a few years ago, in the north of BC almost every home had one, and of course we did some travelling in three different models. I think they were all GMC's, but my conclusions about them was, for front seat occupants generally plenty of room, but I found the rear seats to be rather uncomfortable, back rest was too upright for me, and the rear legroom was surprisingly cramped.

The ride was also far too hard and jarring unless there was a load on the back. It reminded me of the ride quality of a 3 ton Austin lorry our family business had back in the 1950's.

Of course the more recent stateside and European models may have more room and softer suspension. But even if they have addressed those issues, it would not be for me, as I'm doing less towing now and I wouldn't need such a vehicle.

But if that's what you like then fine, it is important for teh preservation of your caravan warranty to follow the manufacturers criteria.
 
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JTQ

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Our findings completely contradict the above- it is absloutely frightening how easily the Nav tows the Buc-200okg of caravan. 6th is a bit high so we use 5th on single carriage roads and 6th on motorways but the caravan is rock solid even when over taking lorries or being overtaken by those National Buses that fly up our roads.

Just think how good a tow vehicle it could be if the mass was in the right place, the overhang reduced and the roll centre lower.
 
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The DVSA are responsible for caravans, in fact any road going vehicle. They do set up inspection points around the country and they will pull some caravanners in and check the outfits.

Just becasue in the UK caravans do not have to be separately registered (unlike good vehicle trailers) does not prevent the user from being checked and even prosecuted if they find anything wrong.

There can be quite a lot of money at stake in the haulage industry so there may be financial reasons why some commercial operators might try to overload , or conveniently forget to service their vehicles, which is why the DVSA roadside checks do come down hard on illegal HGV's.

Overloading (i.e excess weight) should never be considered to be a normal or acceptable practice. In particular in emergency situations the vehicles braking system will be stressed beyond their normal limits, possibly causing failure but certainly causing more rapid wear and deterioration of performance. But other aspects of the vehicle may also be damaged or prevented from working effectively if excess weight is carried, so it pays to observe sensible and legal loading practices.

Any vehicle that cant stop effectively is of course a real danger, but simply becasue HGV's are considerably heavier than domestic cars, they can cause far more carnage.

However there have been some reports where when a caravan has been pulled over and something is not quite right, the inspectors and police will not let it proceed until the problem is corrected, and if its only a little out of order, they are often inclined to offer advice and allow the user put it right, rather than prosecuting.
 
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I think we are digressing a bit from the topic of this discussion. The issue is not one of overloading compared with the absolute limits specified by the vehicle manufacturers, but of the relative weights between towing vehicle and trailer. I don't think anyone would deny that this is an important criterion, but it's not the only one and there are several others, too, and some of these can cloud the weight ratio effect completely. Therefore, quantifying a weight ratio limit with a fixed percentage only makes sense if the conditions under which it applies is specified, too. Simply saying 85% is for the novice caravanner and 100% for the experienced is not enough. The technical parameters under which these values apply have to be specified, too.
 
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The DVSA are responsible for caravans, in fact any road going vehicle. They do set up inspection points around the country and they will pull some caravanners in and check the outfits.

Just becasue in the UK caravans do not have to be separately registered (unlike good vehicle trailers) does not prevent the user from being checked and even prosecuted if they find anything wrong.

There can be quite a lot of money at stake in the haulage industry so there may be financial reasons why some commercial operators might try to overload , or conveniently forget to service their vehicles, which is why the DVSA roadside checks do come down hard on illegal HGV's.

Overloading (i.e excess weight) should never be considered to be a normal or acceptable practice. In particular in emergency situations the vehicles braking system will be stressed beyond their normal limits, possibly causing failure but certainly causing more rapid wear and deterioration of performance. But other aspects of the vehicle may also be damaged or prevented from working effectively if excess weight is carried, so it pays to observe sensible and legal loading practices.

Any vehicle that cant stop effectively is of course a real danger, but simply becasue HGV's are considerably heavier than domestic cars, they can cause far more carnage.

However there have been some reports where when a caravan has been pulled over and something is not quite right, the inspectors and police will not let it proceed until the problem is corrected, and if its only a little out of order, they are often inclined to offer advice and country
The DVSA are responsible for caravans, in fact any road going vehicle. They do set up inspection points around the country and they will pull some caravanners in and check the outfits.

Just becasue in the UK caravans do not have to be separately registered (unlike good vehicle trailers) does not prevent the user from being checked and even prosecuted if they find anything wrong.

There can be quite a lot of money at stake in the haulage industry so there may be financial reasons why some commercial operators might try to overload , or conveniently forget to service their vehicles, which is why the DVSA roadside checks do come down hard on illegal HGV's.

Overloading (i.e excess weight) should never be considered to be a normal or acceptable practice. In particular in emergency situations the vehicles braking system will be stressed beyond their normal limits, possibly causing failure but certainly causing more rapid wear and deterioration of performance. But other aspects of the vehicle may also be damaged or prevented from working effectively if excess weight is carried, so it pays to observe sensible and legal loading practices.

Any vehicle that cant stop effectively is of course a real danger, but simply becasue HGV's are considerably heavier than domestic cars, they can cause far more carnage.

However there have been some reports where when a caravan has been pulled over and something is not quite right, the inspectors and police will not let it proceed until the problem is corrected, and if its only a little out of order, they are often inclined to offer advice and allow the user put it right, rather than prosecuting.
 
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Prof,
You don't paint a very good picture of road haulage with all this overloading and vehicles not being serviced, I don't think any responsible lorry driver would work for an emoyer that would encourage overloading and driving a vehicle that does not get serviced although some mugs do work for employers like that , in my case I have worked for blue chiphaulage companies who follow the law, vehicles always serviced defects always carried out and for overloading I don't think you have been over a modern weighbridge with a 44 tonner which can tell you to the kg if you are over loaded,
 
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Prof,
You don't paint a very good picture of road haulage with all this overloading and vehicles not being serviced, I don't think any responsible lorry driver would work for an emoyer that would encourage overloading and driving a vehicle that does not get serviced although some mugs do work for employers like that , in my case I have worked for blue chiphaulage companies who follow the law, vehicles always serviced defects always carried out and for overloading I don't think you have been over a modern weighbridge with a 44 tonner which can tell you to the kg if you are over loaded,
I think I have been entirely reasonable. I deliberately used the words "some commercial operators" to differentiate from the majority who are law abiding.

I am please to read that your own driving was managed so well with a company that valued its operators licence.

You are correct I have never been over a weighbridge in a 44 Tonner, and I have no idea why you think it relevant that I should.

It doesn't mean I don't know anything about weighbridges though. I do know the technology exists to provide some highly precise measurements of axle loads at high speed. This is in use abroad, and has been trialed by some ferry companies. The technology has not yet been fully evaluated or approved for weights and measures or compliance with haulage regulations in the UK yet, but as more toll roads and charging zones are introduced they are going to need some way of establishing weight based charges.

As yet these have not been approved for use in the UK, it is likely they will be soon.

The people who are most likely to deliberately take loading risks are the ones who don't have to use a weighbridge for every journey, and it's not always the biggest HGV's that are the problem.
 
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I think we are digressing a bit from the topic of this discussion. The issue is not one of overloading compared with the absolute limits specified by the vehicle manufacturers, but of the relative weights between towing vehicle and trailer. I don't think anyone would deny that this is an important criterion, but it's not the only one and there are several others, too, and some of these can cloud the weight ratio effect completely. Therefore, quantifying a weight ratio limit with a fixed percentage only makes sense if the conditions under which it applies is specified, too. Simply saying 85% is for the novice caravanner and 100% for the experienced is not enough. The technical parameters under which these values apply have to be specified, too.

I don't see the diversion into overloading was too far off topic. The same principles apply. We are particularly concerned about caravans which have such low load margins, that it is all too easy for the unaware to lose track of the mass they are adding to the trailer. This could lead to overloading, and if inspected there might be a prosecution.

Regarding the core of the topic I totally agree with your comment. The degree of reliance placed on the industry advice by so many caravanners, is not justified when the issue is scientifically scrutinised and put into perspective.
 

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