Towing 100%

[TheTravellingRooster]

Hi craigstaiano and anyone else following this post. The issues of Kerbweight & MTPLM and to some degree MiRO is very poignant to me. Might I begin by asking, how you established the kerbweight of your Mazda 6 2.2D TS2 ?. The only facts that I had when I was looking at towing a caravan with the current car was its maximum permitted tow-weight,the gross weight of the car,the gross train weight and the maximum permitted loads on each of the front & rear axles. The figures being offered were ludicrous to say the very least!,non of them anywhere near what I eventually/actually found it to be.
The MiRO was important because of the difference between that and my maximum tow. After allowing for a 110ah leisure battery(25kgs and a modern lightweight gas bottle,(full @11kgs) 36kgs kgs in total into the caravan I could then move on;so to speak.
The caravan that we have has a MiRO of 1426kgs (actual 1440kgs) and an MTPLM of 1750kgs,it is used as a large comfortable two berth and the un-used MTPLM potential is of no consequence. The 'anything else' goes in the car and is distributed in order to conform with the load distribution requirements of the Vin Plate. My car has an actual kerbweight ( as per EU Directive 95/48/EC) of 1638kgs. My maximum tow is 1600kgs. therefore my caravan can never become the 'Tail Wagging the Dog';unless I am unfortunate enough to have a major tyre or wheel problem. When I go the few miles to storage ( collecting or returning)I am towing at between 90% & 92% depending on the amount of fuel in the car. When the car has the upside-down map reader/passenger and all of the trappings including the items that won't go into the caravan then I am towing at 88% at the start of my journey. At the point of needing to fill the tank I am at 90%. I have been towing large trailers & caravans since 1966.

 

[Lutz]

Just a couple of comments on the above reply.

1. EU Directive 95/48/EC defines MIRO and does not mention the term kerbweight. There is a small difference.

2. To say that the caravan "can never become the 'Tail Wagging the Dog'" simply because of an 88% weight ratio is rather simplistic. Maybe the likelihood of it happening is relatively remote but, depending on other circumstances, it can happen even though such a weight ratio is relatively favourable. The lower the weight ratio the better, but even at 85% there is still no absolute guarantee.

3. There is little point in distinguishing between 88% and 92%. I challenge anyone to be able to tell the difference in the way the outfit handles at these two levels. I reckon one would need at least twice the difference between the two before you would feel any appreciable change, always assuming all other conditions remain equal.

 

[ProfJohnL]

Hello Rooster,

I cant help feeling that your last reply may add confusion to what has already been a long and difficult thread.

Technically yes your actual towing ratio does change with the fuel load and passenger compliment of the car, but the industry standard measure of ‘Towing Ratio’ is rightly or wrongly consistently based on the cars kerbweight and the caravans MTPLM.

Thus regardless of how you load the car or caravan the recognised towing ratio will not change.
Its not a perfect solution but it does allow outfits to be compared by mass criteria, and it is the method by which the apocryphal 85% good towing guideline is calculated.

 

[DerekBrad]

I am rather concerned that you do not check the moon's phases before towing, as we all know that the proximity of the moon to the earth affects the gravity and therefore the weight. Be careful out there!
Happy caravanning every one.
Regards
Derek

 

[WatsonJohnG]

It also affect some people's behaviour when its full which is why they were referred to as lunatics from la lune the French for the moon
It doesn't affect kerbweight though

 

[Lutz]

It doesn't affect kerbweight though

Oh dear, you shouldn't have written that. The boffins will jump at you right away to remind you that it does affect weight, but it doesn't affect mass. However, unless you go caravanning in outer space, you won't notice the difference.

 

[DerekBrad]

We've been caravanning since 1973, but I'm so scared after reading the scientific arguments/posts referring to weight issues, that I'm thinking of giving up.
Bon chance!
Derek

ps. I've never used a noseweight gauge.

 

[WatsonJohnG]

It doesn't affect kerbweight though

Oh dear, you shouldn't have written that. The boffins will jump at you right away to remind you that it does affect weight, but it doesn't affect mass. However, unless you go caravanning in outer space, you won't notice the difference.

Possibly there could be if you own a Lunar Meteorite

We did have an Ace Award Nightstar but noticed no weight loss----or gain

 

[TheTravellingRooster]

Hi Prof John L & anyone else following this post. Yes this has and 'Is' (not yet finished) a long and difficult thread. It has been made-so by some that meander of line,so to speak. Whilst I cannot disagree that the easy route is to take the extremes (minimum at one end and maximum at the other) the kerbweight is not always easy to establish;and the figures are not as is often claimed in the places that people are directed to. In my case I had a real problem with both The "Tablet of Stone" Data Base & the UK division of the manufacturer of my car. I was intent on establishing my correct & documented kerbweight as a "Belt & Braces" job in the event of needing written confirmation. It has still not been resolved,I resorted to a weighbridge that was accurate to 10kgs;this figure was later confirmed on a VOSA Dynamic Axle Weighbridge;accurate to 0.5%. (Both the car & caravan now have Kerbweight & MiRO that are my starting points). This was all to establish my kerbweight as per EU Directive 95/48/EC as in The Practical Caravan Magazine (in the blue pages).
However,back to the subject. The unfair/biased method of determining outfit matching as used by many caravan sales people, and as advised by the industry rightly caters for the novice caravanner and this will & often has had them running off to get Chelsea Tractors to tow caravans that would in reality never be loaded to the MTPLM (maximum).When the weight of the tow vehicle (as in my case) was totally fictitious and ludicrously low on the "Holy Grail" Data Base then that could prohibit any further notions of caravanning as a hobby/pleasure interest. The figures that I have quoted in my earlier post situation are not there to demonstrate that I can or will bend the rules,more to the point they are there to show that a caravanner that understands the Legal Figures can use them to advantage.In my case to use a perfectly capable Sports Estate with a (now known kerbweight) to pull a van of my choosing with a large MTPLM so as to enable a substantial van to be used as a large & comfortable 2berth;therefore avoiding an unnecessary Chelsea Tractor purchase.
The truth of the matter is that while car/vehicle manufacturers continue to promote the notion of "our vehicle will tow" for example 2500kgs;but the actual kerbweight is under 2000kgs (promoting a 20% over 100% factor) then there is a lot still to be done in the area of promoting "Safety in Caravanning";if for no other eyes, than those of the "Entered Apprentice Caravanner"
It is my considered opinion;for what it's worth,that never should towing of caravans/trailers/horse-boxes and the like over 100% be legal on The Queens Highway,also rather than increase the 85% as an advisory figure for novices;I believe that it should be reduced and for a probationary period/recorded mileage of towing experience .Indeed to take this up a notch, there could be a Towing Tuition Course linked to a certificate of proficiency;similar to that of Motor Cycle Riding with higher powered machines. There are enough old airfields and the like up & down the country to put a scheme into place I'm sure.

 

[Lutz]

If there were going to be some sort of legal requirement based on weight ratio then it only makes sense to use the "Mass in Service" documented in Section 4 of the V5c certificate. It would be unreasonable to expect owners to have their cars weighed at some approved weighbridge and carry seperate documentation. If there is any conflict between the two figures, why not have the V5c certificate updated?
Regarding being able to tow a heavier rated caravan because one is never going to make full use of the MTPLM, I think that is the exception rather than the rule. Quite a few caravans have relatively low payloads and, judging what most people carry in the caravan when they go away, it is more likely than not that many have difficulty in actually staying within the MTPLM.
One possibility would be for manufacturers to quote two maximum towloads, one for low loader trailers, the other for caravans/horse boxes, but then things get very complicated. Where does a low loader finish and a caravan start? How does one handle folding caravan trailers, for instance? (Opel, however, already quotes higher permissible towloads for trailers under 1.4m height for some of their models)
In Germany there is already a legal distinction between trailers and caravans. To be allowed to drive at 100km/h, the weight ratio must be no more than 100% in the case of caravans, but other trailers may go up to 120%. A year or two ago these figures were raised from 80% and 100% respectively, because experience had shown that the risk of an accident did not go up significantly due to the change. If that is the case there, why is 85% still being recommended in the UK? Are the conditions so different?
What gets me is that no attempt is made to differentiate between an old outfit where the car has no ABS, the caravan no shock absorbers and no stabiliser and a modern one that has all these things, and more. So much has been done over the years to improve safety that I think it is legitimate to question the continued validity of the recommendation. It just doesn't make sense, for example, to restrict yourself to 85% if the caravan has ATC or its competitive equivalents.

 

[WatsonJohnG]

Very well put Lutz
I agree with all that except I think that you meant to infer that most people are overloaded because of the low payloads which is not quite how I read it
But the final paragraph in particular is very true
The German regs are interesting and seem to be more in the real world than the world of the CC which tends to be too simplistic in these days of electronic management of stability etc
For years I was under the impression that the then 75% rule was the ratio between the car kerb weight and the caravan unladen weight but then I had the Citroen BX and the self levelling suspension I always felt was big stability factor and probably kept me out of trouble!!
Since the advent of computers information is now much more readilly available with all viewpoints expressed on forums
Sadly not all people have access to the information from forums etc and some aren't interested as witnessed in our local newspaper last night and posted elsewhere on this forum when a driver had 10 people in his caravan and towed from Stoke to Wales
I wonder if he worked out what his percentage car/van was??
Regards
Ignorance is bliss --but scary!

 

[JeffandDi]

Not wishing to fan the flames, and perhaps Nigel the editor can comment:-
When the tow car of the year awards are done why not test the all the cars (that can legally tow) at 100% as well as the recommended 85% and if you want to go all the way tow at the vehicles maximum as well. That would at least put the matter to bed. After all you have the cars, you have the vans, the experienced personnel and the off road test track all available. For example the Mondeo you tested can pull 2000KG. Why not test that one popular car at the very least at 85%, 100% and max. Dont cite cost or time as a factor either as this is the biggest question out there for caravanners so I'm sure you can get the money back!

By not doing this it gives the impression that the clubs/magazines are worried what the outcome would be. If you say "we stick by 85% rule" then I throw down the gauntlet and say prove it! Its easily done.

 

[ProfJohnL]

There never has beeb a 7%, 75%, 85%, 100%, RULES. they have only ever been suggested guide figures for nose loads and towing ratios. The continued reference to them being rules reinforces the misguided perception that they have any legal validity - which they don't.

Only 100% has any legal significance when it comes to the drivers licence entitlements, which has nothing to do with the vehicles capability.

JeffandDi
I agree that the caravan mags should explore the available towing ratios of the vehicles they test, but I do have a concern:-
We know from this forum and other sources that the towing characteristic of an outfit is affected by the way the load is distributed in an oufit,
It is quite possible for an outfit with an 85% ratio can be badly loaded and make it very prone to instability, (The Bath University study has admirably demonstrated this). It is I feel reasonable to assume that the greater the load ratio, the more sensitive to load distribution an outfit will become.
Consequently if a magazine were to apply tests at higher load ratios we would need some evidence of loading to show that it was 'best' for that particular outfit.

 

[Lutz]

Notwithstanding the last two replies, I'd like to add that an outfit that handles well at 100% can only be even better at 85%. Surely that alone is a case for testing at the towing limit.

 

[JeffandDi]

I feel sure many more people would post on this forum if they felt that what they posted would not be over analysed by someone else and picked apart. I made what I thought was a valid suggestion.

There is nothing wrong with using the word "rule" and it's definition does not have to pertain to legality. After all there is a popular saying when driving on the motorway "only a fool breaks the two second rule". It has no basis in legality nor is it enforcable but its meaning is understood regardless.

 

[Dustydog]

I feel sure many more people would post on this forum if they felt that what they posted would not be over analysed by someone else and picked apart. I made what I thought was a valid suggestion.

There is nothing wrong with using the word "rule" and it's definition does not have to pertain to legality. After all there is a popular saying when driving on the motorway "only a fool breaks the two second rule". It has no basis in legality nor is it enforcable but its meaning is understood regardless.

Sadly Jeff whilst we all know about "rules and guidelines" the idiots who may benefit from the many words of wisdom rarely read these pages. In the event they do, then it is only correct we all try and give accurate technical answers with out perhaps being too pedantic. I'd hate newbies to feel they were being mislead in any way.
I agree with your 2 second point on the motorway. When towing I prefer a bit more distance just in case.....

 

[TheTravellingRooster]

Hi toJeff&Di,and to you all out there. This is in my view a very valid point and if nothing more would open up a whole new pragmatic approach to the "Old Chestnut". * Please take note, I an not advocating a raising of the 85% advisory figure for Newbies/Novice Caravanner's. There is however,as with all new approaches to an old stuck in the mud issue;not a simplistic fix!.
Before any figures to determine what is or is not possible, there has to be a Solid Foundation or Starting Point established.
Working with the EU Directive as to kerbweight there has to be an accurate weighbridge facility available,manufacturers figures and those of Data Bases(one in particular) are unreliable (to put it at its bluntest & most polite definition);also to validate the alleged MiRO of the Test Vans. This is the first and most essential hurdle. A Dynamic Axle Weighbridge (as used by VOSA & accurate to 0.5% is as good as it is ever likely to be) will then level the playing field. Once these starting points have been established, then anything and everything that goes into the car and caravan can be accounted for and logged.
However,the first variable now comes into play. Not everyone will have a Modern Technology Car and Caravan;some will be older cars and more up-to date caravans,and some will be older caravans and swanky new cars. Some indeed will have older cars and caravans. Not least of all are the variation potentials with Twin Axle Caravans on borderline Tow-Vehicles & of course the older caravan on the back of an outrageously over-capable vehicle. The question of costs could be split between all parties with a "Vested Interest" in an endeavour to project/promote Safety in Caravanning,& themselves to their potential & existing audiences. In that, I refer to all involved with the World of Caravanning as in;The Towcars/Towvehicles,Caravan,The CC and The C&CC,The three Principle Caravan Magazines,and not least of all,VOSA and The NCC.
Despite the fact that this proposed notion is intended as a serious and long overdue, more in-depth and pragmatic approach to an Old & Battered Conker (Chestnut)it might benefit a little from some Spicing Up. I propose that Jeremy Clarkeson & Co are invited to input a few of the insanely stupid acts that some out there have been known to do.

 

[TheTravellingRooster]

Hi to Derek. With reference to your :- ps. I've never used a nosewight gauge. Perhaps you have used the short prop & bathroom scales!.
It is my opinion,for what it is worth, that you are highly likely one of those "Season Caravanners" as refererd to on another Caravan Forum, that we could well do with giving a 'Wide Berth' to. I have been towing very large and heavy trailers and caravans since 1965,having passed my test in 1964. For some years after first taking up towing I was able to judge with considerable accuracy the weight of the hitch at the Ball-Cup position. I did this until I saw the consequences (in 1966) of Excessive Nose-Weight on the rear of a commercial vehicle.It caused a failure to the frame of the Tow-Bar assembley while the vehicle was on route to the East Coast, going over The Woodhead Pass to Sheffield on route. It made it necessary to involve a Mobile Welding Technician and caused a 5hr delay in the journey. The loaded vehicle had the trailer loaded & hitched, ready for a very early((6am) start from Liverpool City Centre. I was the unsuspecting driver and had put my trust in an "Old Hand", (at this lark).
Never again,I always Validated the Nose Weight myself,and where necessary made adjustments.

 

[Lutz]

There is nothing wrong with using the word "rule" and it's definition does not have to pertain to legality.

The Oxford Dictionary defines a rule as "one of a set of explicit or understood regulations or principles governing conduct or procedure within a particular area of activity". While this does not imply any form of legality, it does suggest more than just a guideline principle and that there would be consequences if the 'rule' is not adhered to. For this reason it is more appropriate to use the terms and 'guideline' or 'recommendation' as they are less like to cause unnecessary concern.

 

[DerekBrad]

Hello TR
I'm usually quite pleased when fellow caravanners give me a wide berth, they're usually travelling at an excessive speed! What was the towball weight on the ill-fated vehicle?, and was the tow bar maintained in good codition? So many unknowns in the saga.
Seriously, I've always considered that the noseweight of my van would remain fairly constant given a standard range of kit in front locker, weight at front, etc. and although I am not an "every weekend" caravanner, I do consider myself to be a responsible and steady driver (IAM member plus 52 years on the road) To be honest, I did use the 'prop and scale' method for the first time this summer out of curiosity, and was not surprised to note that the noseweight was 7Kg below my vehicle's limit. I also make sure that there is sufficient weight in my car to give a solid base with which to tow.
Thanks for your comments..I love the forum!
Regards
Derek

 

[JeffandDi]

Whilst looking at the other numerous un-cut-and-pasted references to the word one caught my eye which was about "having power and restrictive influence over". I am left wondering whether this was appropriate both to the clubs and also to persons on this forum.

You may have seen in the readers letters section of this months mag on this very subject and in reply to the Star Letter the editor mentions "caravanners who need to be protected from themselves".
I wonder how many of PC's readers feel this is justified and how many believe it to be arrogant presumption.

 

[ProfJohnL]

Hello JeffandDi

I’m sorry if my comment has upset you, May I assure you it was not intended specifically for you, as you will see it preceded my greeting to you. Whilst I did not intend to upset you, I make no apology for the intent of the comment.
As far as I am aware this is a public forum, where ideas and views may be put forward but they are then open for discussion.