Towing Limits

[PETERA]

I was debating towing limits with a friend of mine last week and he asked me a quite reasonable question to which I did not have the answer.

It is recomended that the total weight of the towed caravan is no more than 85% of the kerbweight of the towing vehicle.

Why then has his VW 2.5 Transporter have a maximum towing capacity of 2500 kg when the kerbweight is around 2100 kg ?

I asume if VW print that the towing capacity is 2500 kg then it is legal to tow to this weight ?

Any answers ?

PETERA

 

[JohnandNic]

No doubt other more knowledgable readers will have better answers, but as I understand it. You can legally tow up to what the towing vehicle manaufacturer states is the towing limit, in this case 2500kg. However, various bodies eg CC have guidelines that say for a stable tow you should restrict the trailer weight to 85% . This is not a legal limit tho'.

Hope this helps

John

 

[Lutz]

Yes, John has got it right. Perhaps it's just worth adding that if you passed your driving test after the 1st January 1997 and hold a category B licence, then it is only legal to tow up to the kerbweight of the towing vehicle, even though it may have a higher manufacturer's towing limit.
Having said that, keeping within the magic 85% ratio is no guarantee that the outfit will be stable, but it does increase the margin of safety.

 

[ProfJohnL]

Hello Petra,
Further to Lutz comment,
If you are a post 1997 driving test than your licence aslo limits the driver to a max combined MAM of no greater than 3500kg. MAM stands for Maximum Authorised Mass, so its not what the vehicle weighs its what it can legaly wheigh when fully loaded. Now I understand the Transporter you have has a kerbweight of 2100kg and from a quick search on the internet, ot seems it has a payload capaity of about 800Kg whoch gives a MAM of 2900Kg. That mens you can only tow a caravan with an MAM of 600Kg. The nose weight does change the figre slightly and may allow a caravan of about 675Kg MAM, but that depends on loading.

 

[colin-yorkshire1]

yes quite right prof when we had the m/home it had a kerb weight of just under 2.5 ton max loaded nearer 3.5 ton but would tow a trailer of 3 ton, towards the end of our ownership we used to take a fiesta with us but in that event the wife could not drive it with the car attached having passed her test in 1998 (late learner) as the total vehicle weight was 3.7 tons.

 

[JohnGriffiths]

Petera,
You must remember that if you were towing a low slung block of iron on twin axle trailer it would tend to be much more stable than a high sided single axle caravan with weight distributed unevenly all around and subject to aerodynamic effects. That's one reason why the manufacturer can quote figures much higher than the 85% of kerbweight.

 

[ProfJohnL]

Hello John,

I understand your comment, and whilst in essence it is right, it might make a little more sense to look at it from a slightly different perspective:

The car manufactures do tests to establish a maximum permissible towed weight using a trailer loaded with weights. Caravans are rather different having large bodies and a relatively high centre of gravity which tends to make them more difficult to tow, so the UK caravan industry suggests only towing a caravan of no more than 85% of the cars kerbweight. This suggestion has no legal basis and is purely a guideline.

 

[Surfer]

My argument is that the kerbweight of a car is with one passenger, fuel and oil, but when you add another passenger plus luggage then theoretically the guideline should be 85% of that weight and not the kerbweight. Either way it is of n o relevance if stopped by VOSA as they will look at the gross weight of the car and the MTPLM of the caravan, however it is recommended fo the sake of other motorists that a novice complies with the guideline until they are confident about towing.

 

[Lutz]

The weight ratio is always calculated on a worst case scenario basis. It will always be more favourable when the car is loaded up or the caravan not fully laden, but the actual figure is meaningless really because it cannot be compared with any other. It can't be used as a quantifiable measure of how stable the outfit is.

 

[Steve L]

All the legal jargon quoted is about right.
85% of the kerbweight of a tow vehicle was considered by some boffin, to guarantee some sort of a safe towing situation. But that is poppy ****. Loading your trailer/caravan correctly as per the PC help chart does a better job of giving a safer towing situation
Motor manufacturers calculate vehicle pulling capacity by taking into the equassion, the engine power, vehicle weight and vehicle payload capability. Very often this equates to the kerbside weight of the vehicle and occassionally, especially with 4X4's and comercial vans, the trailer capacity is far more than the vehicle weight.
I have towed for many years at 100% or above and as long as you load correctly it is acceptable to do so.
For instance I used to tow an Ifor Williams 3500Kg goods trailer with a Diahatsu F70 short wheel base 4X4. I loaded 500Kgs 0f goods into the Diahatsu and loaded the trailer to 3500Kgs giving a total gross train weight of 5500Kgs which equated to 175% of the loaded tow vehicle. This towed fine so long as you respected what you are driving. 40 Mph was average on main roads and 60 Mph was obtainable on dual carriageways and motorways. Fortunately the wheel pitch of the trailer fitted neatly into the grooves on the wornout 1st lane of motorways, otherwise, we would of been in real trouble, as the trailer could control the tractive vehicle.

 

[JohnGriffiths]

Hello John,

I understand your comment, and whilst in essence it is right, it might make a little more sense to look at it from a slightly different perspective:

The car manufactures do tests to establish a maximum permissible towed weight using a trailer loaded with weights. Caravans are rather different having large bodies and a relatively high centre of gravity which tends to make them more difficult to tow, so the UK caravan industry suggests only towing a caravan of no more than 85% of the cars kerbweight. This suggestion has no legal basis and is purely a guideline.

Sorry Prof John isn't that pretty well exactly what I said? The OP just wants to know why a van manufacturer can quote towing weights greater than 85% of kerbweight and we have both given the same reason haven't we?

 

[ProfJohnL]

Hello John,
Yes we do agree about the effect, but I was slightly concerned that your post gave the impression the car manufactures based thier towing tests on caravans and then added a bit more capacity to allow for lower but heavier trailers. In practice, the car manufactures only consider the heaviest trailer and make no conseesions for caravans. It is only the UK caravan industry that that uniquelly makes the suggestion of 85%. The car manufacturers are happy with their stated limits, but it is upto the driver to decide if they are happy to use the available capacity or to derate in view of the size shape or configuration of thier particular outfit.

 

[JohnGriffiths]

Yes I'm aware they test purely on mechanical strengths of engine, transmission, brakes etc and it certainly wasn't my intention to suggest that manufacturers base their tests on caravans. But yes, us caravanners must remember that although we tend to always think in terms of towing caravans most of these vans will have a life towing things like construction plant on low trailers.

 

[xtrailman]

i have just renewed with green flag today.
Its worth noting that in the documentation, it clearly states, that if the caravan weighs MORE THAN THE CAR.
Then it will not be recovered.

 

[Lutz]

That's not as clear as it may seem. Does it refer to actual weights or MTPLM versus kerbweight? It's rather ambigious, at least the way you are quoting the documentation.

 

[xtrailman]

That's not as clear as it may seem. Does it refer to actual weights or MTPLM versus kerbweight? It's rather ambigious, at least the way you are quoting the documentation.

From the Mayday policy book. (green flag and caravan club)
page 8
Caravan and trailer cover.
Whats covered:
Your caravan or trailer will have the same cover as the insured vehicle when being towed by the insured vehicle provided:
The weight of the caravan or trailer when loaded is not more than the kerb weight of the insured car.

 

[ProfJohnL]

Hello Ray,

I know you havn't formulated the text from green flag and I don't expect you to be a spokes person for Green Flag, but based on what we have seen over recent months on this forum, - it begs the question of how will Green flag know the Kerbweight of the car?- its not recorded anywhere with any certanty of accuracy.

 

[Lutz]

If that's the wording of the insurance policy, so be it, but what do they mean by 'the weight of the caravan or trailer when loaded'? Do they mean the actual loaded or the fully loaded condition? If their interpretation is the former, then quite a lot of outfits with a weight ratio well under 100% would already not be covered.

Hello Ray,

I know you havn't formulated the text from green flag and I don't expect you to be a spokes person for Green Flag, but based on what we have seen over recent months on this forum, - it begs the question of how will Green flag know the Kerbweight of the car?- its not recorded anywhere with any certanty of accuracy.

I would go one step further and say that there is not one single legally acceptable document that one can produce which states the kerbweight. The law doesn't even recognise the term 'kerbweight'.

 

[xtrailman]

I would expect, that should the plated caravan weight be greater than the kerb weight, then that would be grounds to refuse the service.

If you don't like the terms, you have a choice, don't use them?

 

[ProfJohnL]

Hello Ray,

Choosing and alternative breakdown service is of course one choice, but how do they define "kerbweight", and where will they get the information to enforce their clause. I honestly belive that a customer could challenge the clause as an unfair contact term, as kerbweight is not definable, so how could a customer know they are falling foul of Grenn Pennants limitation, equally how could the company prove the trailer exceeded the "Kerb weight".
They can't so it is not enforceabale.

 

[PETERA]

Thanks for all the replys.

Given the information recieved then how about this scenario.
Transporter has a kerb weight of 2100kg and a payload of 1000kg. Maximum combinded train weight of 5200 kg.
So load up the Transporter with all you need to carry, say 500kg. Effectivly raising the kerbweight to 2600kg.
Caravan has a MTPLM OF 2000kg.

Total train weight well withing the max limit and Caravan well within the 85% mark.

No problem ????????

PETERA

 

[ProfJohnL]

Hello PeterA

It dosent quite work like that, the "Kerbweight" (if you can actually find it) never includes pay load, so the 500Kg yoiu mention does ot change the "kerbweight"

Just to expand a little,
Kerbweight has no legal definition, so manufactures are not obliged to publish kerbweight data - . Some manufacture do publish a kerbweight, but invariably if a vehicle in kerbweight condition is actually weighed, it weighs more than the published figure. - There can be various reasons for this, for towers, then the weight of the tow hitch, any addition in car enetertainment, paint finish, special adaptions, etc. - Consequently there is no reliable data base that can give a recovery company the actual kerbweight of your car.

This goes to show how difficult it can be to clarify some aspects of vehicle weights and loads.

 

[PETERA]

Thanks for all the replys.

Given the information recieved then how about this scenario.
Transporter has a kerb weight of 2100kg and a payload of 1000kg. Maximum combinded train weight of 5200 kg.
So load up the Transporter with all you need to carry, say 500kg. Effectivly raising the kerbweight to 2600kg.
Caravan has a MTPLM OF 2000kg.

Total train weight well within the max limit and Caravan well within the 85% mark.

No problem ????????

PETERA

 

[ProfJohnL]

Hello PeterA
I'm not sure what you intention was by posting a copy of your prevoius posting, It does not change the fact that adding "payload" to a vehicle does not increase its "kerbweight".

In your case if the "kerbweight" has been established as 2100Kg it remains that regardles of how much load you carry.

 

[Surfer]

Green Flag are talking poppy ****! What if the vehicle has a kerbweight of 1500kg, the caravan a MIRO of 1200kg and a MTPLM of 1600kg however the caravan's actual weight at time fo incidence is only 1300kg? How can the refuse service as the caravan's weight is less than the kerbweight but ther is no way that they can decdie the actual weight unless they have scales with them.
Our Mondeo's kerbweight is 1598kg, the caravan is plated with MTPLM of 1600kg however the Mondeo can legally tow up to 1800kg. How will Green Flag figure that out? As pointed out in earleir posts, many kerbweights are meaningless as the moment you add on an option the kerbweight increases!