I'm confused about towing limits

I suspect that there is confusion over the definitions of weights here. It is absolutely correct that gross train weight for your outfit must not be exceeded.

The in-service train weight is the total of the actual weight of your car plus the actual weight of your caravan while you are driving on the road. The in-service train weight must never exceed the gross train weight quoted for your car.

The MTPLM is a weight quoted by the caravan manufacturer and also must not be exceeded. Responsible organisations like the Caravan & Motorhome Club and reputable caravan dealers will advise caravan purchasers to ensure that the MTPLM of the caravan is kept below below about 85% of their car’s quoted kerb weight. This is not a legal requirement but is advised in the interests of safety and avoidance of snaking.

So you CAN tow a caravan whose MTPLM exceeds the kerb weight of your car with the proviso that you don’t exceed the car manufacturer’s towing limit but it is not advised. However, the combined weight of your loaded car and caravan must NOT exceed the Maximum Gross Weight and nor must the weight of your caravan exceed the MTPLM.

It is the plated weights that matter. If the two plated weights (loaded) are greater than the GTW of the towing vehicle, it is illegal even if the actual weights are less than the GTW.

Your second and third paras are correct, Geoff.

Just checked on the gov.uk website and it states:

“The gross train weight is the weight of the fully-loaded car plus fully-loaded trailer and must not be exceeded.”

I guess fully-loaded means when the actual weight is equal to the plated weight, so thanks for that correction Tinwheeler.

👍

The statement on the gov.uk website is a trifle misleading. The gross train weight is not the sum of the GVW of the car and the MTPLM of the caravan as it would suggest. The reason why this is not so is that the GVW of the car includes the noseweight of the caravan, but so does the MTPLM of the caravan. This would mean that one is counting noseweight twice. More correctly, the train weight is the sum of all actual axle loads.

Tinwheeler, you've got things wrong there. What you should have said is:

"If the actual weight of the combination as one unit is greater than the GTW it is illegal even though the sum of the plated weight limits of car and caravan respectively may be greater."

One should add that none of the axle load limits may be exceeded, either, nor may the actual weights of the car and caravan exceed their respective GVW or MTPLM.

There no connection between the towing limit of the car and the MTPLM of the caravan. The towing limit is in comparison to the actual towed load. The MTPLM is an absolute maximum and could be a lot higher.

Just to add an example to make things clearer.

A car has, say, a GVW of 2000kg, a GTW of 3500kg and a towload limit of 1500kg. It may legally tow a trailer with an MTPLM of 2000kg so long as the actual axle load of that trailer doesn't exceed 1500kg.

However, such a combination would require a Category B+E driving licence because for driving licence purposes, the two plated limits are added and that sum (4000kg) would exceed the 3500kg limit for a Category B licence.

I’m not convinced that is right Lutz. My original understanding was the same as your argument but since reading the gov.uk website I think we are wrong and Tinwheeler is right.

That website says the legal gross train weight limit is calculated from the weights that would be effective if both car and trailer were fully loaded. The fact that they aren’t fully loaded in your example is surely irrelevant as far as GTW is concerned.

Maybe this argument will continue .....😀

All I can say is that it's no wonder confusion abounds. 😟

I wonder what the OP can conclude from all this? He started confused and is probably in worse state of confusion now. 😂😂😂😂

Government websites are known for their inaccuracies. Obviously whoever publishes them doesn't always check against the actual wording of legislation.

Fact is that the actual train weight is the sum of all actual axle loads. That's how train weight is defined. Of course, the actual train weight must not exceed the plated gross train weight limit. That gross train weight limit isn't calculated at all. It is determined by test and set by the vehicle manufacturer.

The total weight of the car is the sum of its actual axle loads and that sum must not exceed the GVW. If the caravan is hitched to the car its noseweight is treated as part of the car's overall weight.

The total weight of the caravan is its axle load plus the noseweight and that sum must not exceed the plated MTPLM.