Essential numbers for safe towing
Safe touring requires a clear understanding of the weight limits for your tow car and caravan. Sammy Faircloth outlines the key facts and figures
IN DISCUSSIONS WITH other caravanners, it can sometimes surprise me how little some know about caravan weights and limits. A minority even seem to believe it is acceptable to chuck everything randomly into the cavernous interior of their tourer, without a thought for the stability and safety of their tow car or caravan ( 1).
So for those of you who do not know about the important weights and limits operating for our pastime, here is what you need to bear in mind.
Weighbridge
First, the caravan needs to be weighed and this is carried out at a weighbridge ( 2). These are simply a very large set of scales, used to weigh trucks, tractors and leisure vehicles. To locate your nearest weighbridge, visit www.gov.uk/find-weighbridge or contact the local council.
Most of the weighbridges are operated by private businesses, so you’ll need to call in advance to check opening times, costs (usually there is a charge for each weighing session, for example, just your caravan, or car plus van) and how to get there. Inform them of the dimensions of your outfit, too.
Once the check has been done, don’t forget to collect the paperwork, including the date, vehicle registration number and weight information ( 3).
Tow car weights
Kerbweight is the total weight of the car, including a full tank of fuel and fluids, but excluding passengers and luggage.
Gross vehicle weight (GVW) is the maximum permitted weight of the vehicle, fully loaded. Refer to the car manufacturer’s handbook for approximate weights ( 4).
Caravan weights
Mass in running order (MIRO) is the weight of the caravan when it leaves the factory and is weighed, to include the manufacturer’s standard spec.
This figure won’t include extras, such as a motor mover, air conditioning unit or leisure battery ( 5).
If it is an Ncc-approved van, there will be an allowance in the MIRO for basic equipment including gas bottles, hook-up cable and essential fluids.
Maximum technically permissible laden mass (MTPLM), also known as the maximum authorised mass (MAM), is the maximum that a caravan can weigh to remain legal. This includes all of your personal belongings, fluids, food and accessories.
The data plate on the side of your van usually gives you this figure ( 6), or refer to the manufacturer’s handbook ( 7).
Actual laden weight (ALW) is the actual weight of your van once you have added all of your personal belongings (awnings, chairs, clothes, shoes, buckets, spades and so on) and add-on kit (motor mover, air-con units, satellite dish).
This must not exceed the MTPLM – if it does, you need to leave something behind.
User payload is the amount of dealer-fitted equipment and personal effects that you can carry in the van. It is calculated
‘The caravan needs to be weighed and this is carried out at a weighbridge, which is simply a very large set of scales, used to weigh leisure vehicles’
by subtracting the MIRO from the MTPLM.
Bear in mind that putting heavy items, such as an awning, in your car boot will influence the gross train weight (see below), not the van’s payload.
Noseweight is the downforce on the towball, usually 5-7% of the caravan’s ALW. The correct noseweight is imperative for safe towing. Sometimes it is easy to adjust this downforce by moving items around, but never to the rear of the van – this will affect its stability.
There are various ways to check the noseweight, but the easiest and most accurate is to use a calibrated gauge ( 8).
Alternatively, you could try a set of bathroom scales and a sturdy stick, such as a broom handle ( 9), or buy an electronic noseweight gauge ( 10), which sits on the towball and gives a digital reading once the hitch head is lowered into position.
It is recommended to check the noseweight before every trip.
(To receive a FREE Milenco Noseweight Gauge when you subscribe, see p60.)
Tow car plus caravan weights
At the weighbridge, both tow car (without occupants) and caravan should be weighed, to confirm their combined weight is within the car’s gross train weight (GTW) limit ( 11).
The tow car’s maximum GTW is usually to be found in the owner’s handbook.
This concerns your vehicle’s towing ability, but not matters
‘As well as being aware of the relevant weight limits, it is also vitally important to ensure that you load your caravan safely and in the correct way’
such as the van’s individual load limit and stability performance.
Another crucial figure to consider is the weight ratio of tow car to caravan. The vehicle’s power and weight are vital elements when you decide to purchase a van.
For example, experience has revealed that if a carefully loaded caravan weighs no more than 85% of its tow car’s weight, this should provide a pretty stable combination.
However, an 85% relationship is not a legal requirement, and experienced caravanners will sometimes tow vans weighing almost as much as the tow car itself. But do note that where safety and legality are concerned, the van must not exceed the weight of the car, or its maximum towing limit.
If you are a member of The Camping and Caravanning Club (www.campingandcaravanningclub.co.uk) or the Caravan and Motorhome Club (www.caravan club.co.uk), take a look at their outfit-matching services, which can help you to identify the size of caravan your car will tow.
Safe loading
It is, of course, vitally important to load your caravan safely and in the correct way. Here are some helpful tips on loading:
Avoid filling overhead lockers for travelling ( 12). Items can be dislodged in transit and fall out, damaging worktops or at worst, even injuring somebody.
Heavy kit should be stowed as low as possible and close to the axle line. This reduces the chances of body roll.
Avoid travelling with any water on board, because this can swill around and affect stability.
Resist overloading towards the rear of the caravan. Too much weight and it can start to wobble from side to side.
Secure any loose items.
Load heavy items such as awnings in the boot of your car.
Did you know?
You can be fined up to £2500, be banned from driving and get three penalty points for using a vehicle in a dangerous condition. Find out more at www.gov.uk/ towing-with-car.
Your caravan insurance and manufacturer’s warranty will be invalid if your van is overloaded.
Your driving licence may restrict which vehicles you can tow.
See Practical Caravan’s Buyer’s Guide (p92) for info on the key weight figures for new models.
Final thoughts
You should now be suitably informed and armed with all of the terminology as to what the weights and limits are for both tow car and caravan.
Set yourself the challenge of having your outfit weighed and check you are within the legal limits. The penalties for not checking your weights will far exceed the cost of a trip to the weighbridge. Safe towing!