Caravanning Now

A reliable alternate guide is the National Caravan Council Caravan Towing Guide.

What the law is.

The Road Vehicles (Construction and Use) 1986 act (See both the legislation and Requirements for trailers).

What the Police say.

My major contributor to this rewrite and I understand, from informed sources in one county's Traffic Police, that exceeding the weight limits can lead to prosecution for Using a Vehicle in a Dangerous Condition contrary to section 40A of the Road Traffic Act 1988 (driving a dangerous vehicle or for dangerous driving).

All of the vehicle weights will be shown on the V5 for that vehicle.

Horror story scenario: You have a puncture on the motorway and the Highways Agency or Police attend you on the hard shoulder (we're told it's only a 25 minute window between stopping on the hard shoulder and an accident happening). If they suspect that you are overweight, they will not allow you to continue with the caravan (just over on the nose weight can probably be sorted out by rearranging stuff in the 'van) and you may have to drive off without your 'van and pay for it to be taken to the local pound.
If the van is overweight, you may be lucky and just have to leave stuff at the side of the motorway otherwise you will have to pay for the tow to the pound and if you were over-weight then the courts will decide your remaining costs.

What VOSA (Vehicle & Operator Services Agency) say.

The VOSA say in this PDF.

What the National Trailer and Towing Association (NTTA) say.

The NTTA represents the manufacturers of Trailers and has some good solid advice regarding safe and legal towing which also applies to caravanners.
The NTTA have a page of frequently asked questions, which you can read here.

Don't forget the tow bar.

All vehicles registered since the 1st August 1998 must be European Whole Vehicle Type Approved and so must their tow bar and tow ball.
The tow bar itself will have a plate defining a D value (See here) also look at the page here for more type approval information.

Summary

So, in theory, your towed weight can be up to the maximum permitted in your handbook, which might lead to your tow vehicle and caravan weights exceeding the unladen Gross Train Weight of your which is the absolute maximum combination weight!

Your vehicle weights are all shown on your V5 and these are the weights that the police or highways agency will be using.

In practice however, it depends upon your experience and confidence.

There are two factors that restrict your towing weight.

1. The vehicle manufacturers specify a towing limit for the vehicle which you may not exceed (for example 1800kg).

2. The vehicle manufacturers also specify the maximum gross train weight of the vehicle again which may not be exceeded (for example 3600kg). This should be the same as on your V5.

Therefore, using the examples above, so long as your car and caravan, in total, weighs less than 3600kg, of which, no more than 1800kg is the caravan then with a licence first issued before 1st January, 1997 or if you have passed a supplementary towing test, then you can legitimately drive the combination at 60mph on the motorway.

We've also received the following advice:

When towing a trailer of any type, the Maximum Technically Permissible Laden Mass (MTPLM) of the trailer must not exceed the Maximum Permissible Towing Mass (MPTM) of the towing vehicle.
Other limiting factors include the vertical tow bar load limit of the towing vehicle (see above), the brake overrun limit and the trailer draw bar limit.
The ratios of the masses of the towing vehicle and trailer are not specified in regulations, but the Gross Train Weight (GTW) of the vehicle must not be exceeded.
The MPTM and GTW are defined by the manufacturer and will be noted in the vehicle's handbook.

Thanks also to Dave Milan for the following information:

Remember that when you reach the age of 70, your licence will expire and you will have to apply for a licence renewal and even if you passed your test before 1997, you will then be restricted to a MAM of 3500 kg UNLESS you opt to provide a medical/optical report to retain your entitlement to keep the C1 and D1 parts of your licence.
Any one using a large 4x4 and heavy twin-axle van could quite easily be in contravention of there licence entitlement without realising it.
It should also be pointed out that the entitlement stops on the date the new licence is issued and not on the licence expiry date.
This also applies if you have your driving licence is restricted to a limited period because of an illness that needs to be notified to the DVLA. These include but are not restricted to type 1 diabetes, epilepsy, stroke. The DVLA web page has more information (See here).

Caravan and Towcar matching:

See www.whattowcar.com

How much does my Car weigh:

See Chris's site at www.clicreports.co.uk or www.whattowcar.com for a more up to date list.

How much does my caravan weigh:

Again see Chris's site at www.clicreports.co.uk or www.whattowcar.com for a more up to date list.

For the beginner:

All of the above and make sure that the weight of the caravan is within 85% of the limit.

The WhatTowCar site (again see www.whattowcar.com) also has a calculator.

Glossary of terms:
(See also The DVLA vehicle weights explained)

Vehicle - Kerb Weight or Unladed Weight or Mass in Service or Mass in Running Order. (MRO)	There are various definitions for this (the EU, the Government and your vehicle manufacturer). In some cases it's the weight of your towing vehicle when ready for the road (i.e. empty of luggage, driver and passengers, but including all vehicle fluids such as oil, water, full fuel tank & washer fluid, spare tyre, tool kit, etc.). Section 4 item G in the vehicles V5c certificate quotes Mass in Service which is the same as Mass in Running Order. See also the note below from Barry.
Vehicle - Maximum Permissible Towing Mass. (MPTM)	The vehicle manufacturers maximum permitted weight that they calculate your vehicle can tow. See also Max. Train Weight below.
Trailer - Ex. Works Unladen Weight (EUW) or Mass in Running Order.	The weight of your caravan, with the bits it left the factory with. (i.e. The weight of the caravan equipped to the manufacturer's standard specification.) Note: This excludes any item that you may have added, items like the steps, gas bottles, battery, awning, water containers, fluid in the toilet cassettes, crockery, cutlery, bedding, barbecues, etc. etc.
Trailer - Caravan Allowable Payload (CAP)	The amount of weight permitted by the caravan manufacturer as the payload of the caravan. This includes the gas bottles, steps, battery, spare wheels, bedding, crocks and cutlery, bedding, clothes, water, food and everything else not built in by the manufacturer.
Trailer - Max. Authorised Mass (MAM) or Maximum Technically Permissible Laden Mass (MTPLM)	This is the maximum load that the trailer (the caravan) is allowed to carry + the weight of the trailer (the caravan). (i.e. EUW+ CAP)
Vehicle - Max. Train Weight or Gross Train Weight (GTW)	This is the limit specified by your vehicle manufacturer that determines the maximum weight (of the car and the caravan) and must not be exceeded.

Notes:

From Barry Lawton re "Definition of 'kerb weight'."
Your definition is too simple. The following are extracts from EU Directives:

EU 80/1268/EEC - 6.1.1.2.
For the purposes of this Directive, "mass of the vehicle in running order" means its total unladen mass with all tanks except the fuel tank full, the fuel tank being filled to 90 % of the capacity specified by the manufacturer, and with a set of tools and the spare wheel on board. (Audi use this one in 2010 A4 brochure.)

EU 95/48/EC - 2.6.
Mass of the vehicle with bodywork in running order, or mass of the chassis with cab if the manufacturer does not fit the bodywork (including coolant, oils, fuel, tools, spare wheel and driver) (o) (maximum and minimum)
See also Appendix Method for verifying the masses and axle loads of motor vehicles of category M1
Note the difference i.e. presence, or not, of a driver and/or 90% or 100% fuel.
Total confusion for us caravanners as the difference is about 70kg.