Towing weight, Which is legally correct?
Bit of a pub discussion this.
To tow legally is it:
a. Plated Car Gross train weight Kg minus Car Maximum Authorised mass Kg= car towing limit Kg = maximum caravan mass Kg.
As well as complying with maximum axle limits Kg of car and caravan plus hitch/ car plated nose weight Kg.
eg GTW 3500Kg - MAM 2000Kg = 1500kg = MTPLM of van
Or
b. Plated Car Gross train weight Kg minus Car Maximum Authorised mass Kg plus hitch nose weight Kg = car towing limit Kg = maximum caravan mass Kg. As well as complying with maximum axle limits Kg of car and caravan plus hitch/ car plated nose weight Kg
eg. GTW 3500Kg - MAM 2000Kg = 1500kg + nose weight 80Kg = 1580 = MTPLM of van
I've seen a few threads that raise this question where it has been said nose weight is effectively transferred to the car loading therefore the van MTPLM is minus nose weight? If correct this gives scope for extra van load or towing weight provided GTW and axle loading etc is not exceeded.
Which is legally right? Or have I got both wrong or misinterpreted what has been said? 🤔
There are implications for accidents/insurance and for those with claims for failed axles.
Comments
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This has been discussed a few times before and taking the forces in the time honoured mechanics methods in two perpendicular directions the engine does the 'towing' and so 'tows' all the extra weight horizontally. So I'm in the car tows all the weight camp.
Before the tests were scarped if you didn't have a towing test you could tow only a certain weight, I forget what it was (was it 1500Kg?) but it simply said that, towing a certain weight of caravan. It didn't mention having some of that weight 'transferred' to the car and so as you say you couldn't have I'm towing a caravan of 1560 kg as I have 60Kg of that on the hitch as a defence when pulled over? Do Weighbridges weigh the caravan by themselves or hitched up?
Also it would be too difficult to work out what you could tow with your car?
All the laws here just state a weight of a trailer/caravan, I can't see any mention of some of that being on the hitch?
If stopped and checked I wouldn't like to explain the weight in that way?
A bit of a interesting discussion but I would think most people would just go with the weight of the caravan?
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I think if push came to shove the GTW of the car, the MAM of the car and the MTPLM of the van would be the weights the authorities would be looking at, ie option a.
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The gross vehicle weight of the car includes the noseweight, but so does the MTPLM of the caravan. Therefore you can't add the two together or else you would be counting the noseweight twice. Consequently the towed weight is the axle load of the caravan only, not its total weight. The noseweight is carried, not towed, by the towing vehicle.
Consequently, neither option a) nor option b) are correct.
Per definition, this is how the sums add up:
GTW 3500kg - MAM 2000kg (this includes the 80kg noseweight) = 1500kg towed weight
but
MTPLM of the caravan = 1500kg towed weight + 80 kg noseweight = 1580kg
That is how towed weight is defined in the regulations.
Actually, the allowable towed weight could even be more than 1500kg so long as the plated MTPLM is not exceeded, but then the MAM of 2000kg cannot be used to the full or else the GTW would be exceeded.
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Thank you Lutz, so you couldn't subtract the nose weight from the MTPLM to get within the cars limit.
For example juggling the figures a bit the car manufacturers towing limit is now1450Kg van MTPLM 1500Kg minus 80Kg nose weight= 1420Kg.
Presumably the towed mass is still 1500kg as seen by the cars towing capability and towbar attachment points etc?
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We've had this before (about what is 'towed') and I disagree, mathematically it doesn't make sense but no point in going over old ground. For me 'towing' is the forward force on the tow bar or that made by the engine to pull the caravan forward otherwise all the A level exams and university exam paper questions make no sense when asking to find it? If the caravan wasn't there that extra towing force wouldn't be either. But no use starting that again. The MTPLM is the MTPLM, it doesn't matter how it is distributed vertically. Reply if you wish telling me I'm wrong but I'll keep to that view as that is what I was taught and experiments confirm it.
This is Uk law you're talking about btw?
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I wish anyone arguing the view put forward by Lutz with the Police/VOSA the very best of luck. I'd not want to be that person.
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I don’t know what is so difficult. The car is not towing the full mass (weight) of the caravan, but only its axle load. The rest, I.e. the noseweight, is being carried, not towed. That’s why the noseweight counts as payload towards the overall weight of the car. Anything else and the sums wouldn’t add up.
If you want to read it in the regulations it’s all in Article 2 (Definitions), Paragraph 9, of 1230/2012/EU, as referenced in UK road vehicle legislation.
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I am getting a little confused I have always veered on the side of caution.
We tow a 2016 Swift Conqueror 480 the manufacture MTPLM was 1454kg, as we towed with a Ford Kuga at the time we upgraded to 1550kg, however changed to a Mitsubishi Outlander PHEV with a permissible towing weight of 1500kg and a maximum nose weight of 75kg.
We went back to our supplying Swift dealer and had the MTPLM downgraded to 1500kg, I assumed if the outfit if measured on a weighbridge is should be 1500kg or less including the nose weight on the hitch/jockey wheel or am I missing something ?
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Yes, a 1500kg MTPLM would include the noseweight, but the car would only be pulling 1500 minus 75kg = 1425kg. On the other hand don't forget that when hitched to the caravan the car would weigh 75kg more.
If anyone interprets the law any differently, it's up to them, but the law is actually quite clear that the car is only pulling the axle load of the caravan.
One should not fall into the trap that MAM + MTPLM = GTW.
Mobile weight checks are normally carried out without unhitching the caravan. That means that only the axle load of the caravan will be measured, not the MTPLM. To check whether the MTPLM is exceeded or not, one would have to unhitch and put the caravan on its own, including the jockey wheel, on the weighbridge.
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ps: Why downplate the caravan? So long as the actual weights are less than all the plated ones there is no need to downplate. A car with a permissible towload of 1500kg could pull a trailer with a 2000kg MTPLM so long as the trailer's actual axle load doesn't exceed 1500kg AND so long as neither the GTW nor the car's MAM and permissible axle loads aren't exceeded.
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I am with Lutz on this, and very specifically that "One should not fall into the trap that MAM + MTPLM = GTW."
MTPLM is a limit, not a weight and should not be used when calculating Gross train weight.
GVW of the car is all load resting on the cars axles. That is (car, occupants and luggage + tow ball load).
Towed mass is the weight of everything resting on the trailers axles. That is the total mass of the caravan - nose weight.
Gross train weight includes everything ; actual mass of (car, occupants and luggage + tow ball load) + (actual weight of caravan - tow ball load).
Case in point - if you have a tow bar mounted bike rack, is has no axle. The mass of the rack and bikes is entirely payload for the car. You are not towing the bike rack. You must be under the tow ball load, and under the GVW. A car with no towing capacity (GTW = GVW, or not homologated for towing) can still (in theory) have a tow bar fitted for a bike rack perfectly legally.
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OM, I think what Lutz is saying is as long as you observe the rules you have nothing to worry about.
Our van has an MTPLM of 1550, and max noseweight of 100.
Our car has a max towed load of 1500 and towball load of 90.
I don't need to down plate the max noseweight on the van to be under the max towball load of the car, just make sure it is actually no more than 90.
The same is true for the towed load. I have to ensure that the towed mass is less than 1500.
I can still load the caravan up to 1550, as I know that 90kg of that will be car payload, making my towed mass 1460. But I still have to be under the maximum mass on my car (GVW) and under the maximum train weight (GTW).
Interestingly - my car has a specific clause in the manual that - when towing - allows the GVW to be exceeded by100kg as long as the speed is limited to 62mph.
I.e. When towing caravan or trailer, the 90kg nose weight is allowed in addition to the non-towing GVW. The GTW MUST still be observed.
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It's not my advice. It's taken from the wording of the regulations, as referred to in legislation.
To put it simply, gross train weight is the sum of all axle loads of both the towing vehicle and the trailer. Gross vehicle weight is the sum of all axle loads of the vehicle in question. Hence, gross train weight minus gross vehicle weight is the trailer's axle load. MTPLM doesn't come into it, although even that mustn't be exceeded, but it doesn't enter into the equation.
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I am in an almost identical situation. My car has a towing limit of 1500kg even though it weighs almost 2000kg. The caravan MTPLM is 1550kg and the nose weight limit is 70 kg or 80kg depending on which document from Toyota I look at. Even in the lowest nose weight the towed weight is below the cars towing limit and the outfit below the gross train wright. I carry in the car a print out of the relevant section of the document referred to by Lutz in case I am ever pulled over by Plodd so I can show that I am legal (assuming my weighing is correct).
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I have looked up https://www.legislation.gov.uk/eur/2012/1230 as referred to by Lutz.
Reading Article 2, Definitions, paragraph 7 states, “technically permissible maximum laden mass’ (M) means the maximum mass allocated to a vehicle on the basis of its construction features and its design performances; the technically permissible laden mass of a trailer or of a semi-trailer includes the static mass transferred to the towing vehicle when coupled;”
While I would love to gain an extra 90 or so kilograms of payload, the fact is that the weight borne by the tow bar is still to be included in the maximum technically permitted laden mass of the trailer.
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MTPLM (and total van payload) is independent of node weight. Your van MUST be equal to or less than the MPTLM.
The noseweight aspect is important for the GTW (gross train weight) and weight being towed by the car.
These are separate limits and treated separately.
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The above post can lead to misunderstandings
For a start, MTPLM is not independent of noseweight. It is the total weight of the caravan, including the noseweight. Only the payload is independent of noseweight.
Noseweight is part of the total weight of the car.
The total weight being towed by the car is the axle load of the caravan, so it does not include the noseweight. If it were, one would be counting noseweight twice, once including it in the total weight of the car and again in the towed weight.
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Hi Lutz, that is what I meant. The MPTLM is a stand alone figure. When nose weight is 0 (unhitched) the weight of the trailer is by the sum of the weight of the axles. This must be equal to or less than the MPTLM.
Once hitched, the weight on the towbar is still a part of the weight contributing to the MPTLM of the trailer, whether that is 10kg or 100kg.
I.E. changing nose weight does not change either the trailer weight for MTPLM, or it’s available payload.However, changing nose weight does affect the car payload, as it is part of that payload.
A 1550kg trailer with 50kg nose weight is towed mass of 1500kg. With a 100kg nose weight is 1450kg towed mass.
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