This is perhaps one of the most commonly asked questions when people are considering buying either a caravan or indeed a new car where they already own a caravan.
It would be nice to give a simple one or two sentence explanation but unfortunately, this area is slightly complex and requires a little thought. It also needs a little detailed explanation and quite a few words in order to convey the key concepts!
- The following is based on our current understanding of legislation as at January 2018, which may be liable to change.
It might help if you start by considering four categories that you’ll need to think about when trying to match a caravan and car:
- the law and what it says on the subject;
- what’s technically possible and legally permissible;
- what’s actually sensible and legally permissible;
- what you can afford.
There are two basic truths falling out of that to begin with:
- the fact that a caravan/car match is legal and that the car concerned can technically tow the caravan, doesn’t necessarily make the vehicle or caravan a sensible choice for a match;
- to choose a sensible match, you’ll need to think a little about how and where you plan to use your caravan.
Preparing the ground – practical considerations
In one sense, the answer to the question of matching is easy – buy a very big and very powerful car.
That, of course, assumes that you can afford such a thing and that you don’t have:
- a strong environmental conviction and/or;
- a reduced cost-of-ownership imperative.
Comparatively few caravan owners can say such, so if you’re looking for a sensible and cost-effective match, you’re going to need to engage in some planning and a little mathematics.
A key starting point is to think carefully about your likely usage. For example:
- are you planning to use your caravan and car regularly or perhaps only 2-3 times per year for your annual holidays?
- will you be primarily using it locally, point-to-point type trips at the start and end of a holiday or are you planning to take it on extended touring marathons around the UK and Europe?
- how many people on average will you likely have in the vehicle when towing?
- what sort of landscapes will you be using it in? Paved sites and flat roads are one thing, hauling a caravan up the Pyrenees or taking it off-road onto farm tracks is quite another.
This sort of thinking is important because it relates to the concept of “redundancy” in terms of your selected car for the match and its power delivery. We’ve all seen very small and no doubt economic-to-run cars, struggling desperately to get a caravan up a steep hill. It might be perfectly legal but it’s inconsiderate to other road users and potentially dangerous too.
The message here is select an appropriate vehicle for your probable usage. If you’re planning very long journeys on a regular basis, travelling to countryside with mountains and long steep inclines or taking the caravan off-road, don’t opt for a minimum legal compliance vehicle. Go for one that will offer you some significant surplus power and perhaps in some cases, a 4 x 4 capability.
In passing, remember to check in advance that your caravan insurance will cover you if taking your caravan off-road.
The car’s documentation might state a maximum towing weight of any vehicle (including your caravan) being towed. Your car should also and more importantly carry a VIN (Vehicle Identification Number) plate that’s under the bonnet or sometimes on the side of the driver’s door.
That VIN should specify what’s called a “Gross Train Weight” (GTW). The GTW specifies the maximum weight that your car plus any towed units must not exceed under any circumstances or you’ll be breaking the law.
The government’s official advice states that if your vehicle’s plate does not contain a GTW, it must not be used for towing at all.
If you’re stopped by the police, it is the GTW and possibly the car’s maximum towing weight figures they’ll be interested in and will use to judge whether or not you’re in trouble. Excuses such as “I didn’t know” or “my caravan must weigh more than I thought” typically will count for nothing.
How heavy is heavy?
However experienced you are, it’s unlikely you’ll be able to look at a potential car/caravan combo and say immediately, with any accuracy, how much it’ll weigh. There are just too many variables such as how much luggage you have, how many passengers, the weight of the caravan’s water and gas tanks and so on.
To be sure and to reduce your chances of ending up in a frank discussion with the police:
- use the documented un-laden weights of the car and caravan;
- add to this some estimates for variables such as those mentioned above. There are plenty of useful guides around that can help;
- don’t forget your passengers (remember, 5 large people in a car can add over half a tonne to your laden weight).
What car is right? Power considerations
The above sections are relatively simple – but things get a little more complicated in terms of what’s possible and what’s sensible.
This introduces two new concepts – the Maximum Technically Permissible Laden Mass (MTPLM) of your caravan and your potential car’s “kerb weight” or “Mass in Running Order (MIRO)”.
These are both usually specified in the caravan’s and car’s documentation. They essentially provide a stipulation of the maximum laden weight your caravan can be and still be safe and a figure for how much the car weighs without a significant load (one 75kilo driver is included).
Many of the main caravan associations recommend that the car should never try to tow a caravan if its MTPLM exceeds 85% of the car’s kerb weight or MIRO. That should be a powerful figure to use when thinking about what car to select.
Other legal considerations
A car’s tow bar (which must, in itself, be legally compliant) will have a maximum loading capacity figure. Your caravan will also have a “nose weight” figure which stipulates the maximum it can safely carry in terms of the weight passed onto the tow bar of the car.
This must not be exceeded but can sometimes be put at risk by poor caravan loading. Remember to keep heavy items stored in the caravan over the axles – not at the front of the vehicle.
Other legal issues will typically apply to any car you’re considering, including lighting plate, number plates, rear view mirrors and so on. These too are helpfully documented on the government’s site though again, they may not influence your choice of owing vehicle as such.
To try and help you focus on the key points in matching a car and caravan:
- know how you plan to use the caravan (as far as you can say in advance);
- try to select a towing vehicle that offers a comfortable margin of power/weight excess over and above the legal minima plus 4×4 in appropriate circumstances;
- be clear on the caravan’s maximum permissible laden weight;
- know the car’s kerb weight and it’s GTW from the VIN plate;
- use sites that can help you estimate the weight of your planned luggage and passengers;
- add the weights together and be sure that overall, the GTW is never exceeded or even approached;
- don’t select a car where the kerb weight is less than 15-20% higher than the caravan’s MTPLM;
- if in doubt about the GTW once everything is loaded – take your vehicle to a local weighbridge!