In this ultimate guide to towing series, Robert Pepper discusses choosing a caravan or trailer to match your tow car and vice-versa, including what you need to consider and what makes a good tow car.
You own a tow car and want to choose the right-sized caravan. Or you own a caravan and want to buy the right-sized tow car. Or you own neither and just want to get it right. This article is for you.
What we’ll cover here is towability; the ability of the tow car to effectively tow the caravan – not whether or not you want a hybrid, pop-top, east-west bed or interior cooking. Those decisions are subjective, whereas towability is more about specifications and safety. We’ll talk about weights a fair bit in this one, which is why it immediately follows our detailed explanation of towing weights. So look there for terms like ATM and TBM because you’ll need to be familiar with all those weight-terms to follow this article.
The big problem with modern caravans
A big problem with modern caravans is being overweight. We can debate how we got here over happy hour, but for the moment, let’s just deal with the problem at hand. Most caravans are custom-built to a greater or lesser degree, and therefore, the exact weight may not be known until your specific unit rolls out of the factory. However, you may have done all your calculations based on a given weight, and it can be very disappointing to discover that your 2,000kg caravan actually weighs 2,300kg or heavier.
The way to fix this is to pay a deposit and then agree on a maximum figure for the final van. If the van comes in less, you take it, if not, deposit refunded if you prefer. Caravan makers hate this approach; on one hand they’ll assure, but not guarantee a given weight but won’t want to put anything in writing. But given the amount of people who have been burned, this approach is pragmatic.
The most important advice in this article
I’m not going to make you scroll to the end! It’s simple and not what you wanted to hear, but if you restrict your caravan weight to 2/3 of the max tow, you’ll find a lot of these weight and compatibility worries just magically disappear. So if your max tow is 3,500kg, then consider a loaded caravan of 2,400kg or below. You’ll also find the tow a lot more stable and safer. If you want to tow a 3,500kg van, you’re best off looking at tow cars that can handle 4,500kg such as the big American utes or light trucks.
But I need to go heavier than 2/3!
You can, but this is where you start to need to be very careful about weights.
So here are the things to check when you buy a van for your car or vice-versa:
1. Are there any conditions on the max braked tow capacity, and what are your specific model weights?
Sometimes the max braked tow is only achievable with special tow packs or with weight distribution hitches. Sometimes, the capacity varies with trim level, transmission or engine size. For example, all Land Rover Discoverys and Defenders used to be able to tow 3,500kg. Today, not all can, so be very specific about checking your specific vehicle’s capacity.
2. Is the max braked towing capacity MORE than the caravan ATM?
The first trailer spec to look at is the caravan’s ATM, which is the maximum it can weigh. Now, you may not intend to ever fully load the van to that degree, but it is a worst-case scenario for your tow car. For example, my van has an ATM of 2,800kg, tare of 2,150kg, and I generally tow it at 2,350kg. So it’s well within my max tow of 3,350kg, but I could tow it at its max of 2,800kg.
Now, there is a myth that, by law, your max braked tow must be more than the trailer weight. For example, say you’ve got a Forester that can tow 1,500kg, and you’re pulling a car trailer that weighs 1,000kg but has an ATM of 3,000kg. Well, that’s legal so long as the car trailer isn’t loaded beyond 1,500kg, or in other words, you can put 500kg of load on that trailer and still pull it with a Forester.
So why do we advise you to choose a tow car which can tow as much as the caravan ATM? Because with car trailers, there’s a big payload, which is the difference between tare and ATM, say 1,000kg unladen and 2,500kg laden, giving you a payload of 1,500kg. With a caravan the differences are much smaller. The van may weigh 2,500kg, payload 500kg, ATM 3000kg, and its weight may vary only by 200kg or so, mostly depending on water.
There are circumstances where you may choose a caravan with a larger ATM than your tow car’s braked tow, but then you’d be restricted in what you can pack in your caravan so as not to exceed the braked tow limit.
3. Will the TBM be exceeded?
The tow ball mass limit is set on the tow car, not by the caravan maker. The caravan maker will have a specification for the TBM, but expect that to be approximate, and like all figures, it’s best to leave some margin. As with all claimed weights from caravan makers, assume that spec is on the low end, so if it’s claimed 150kg, assume it’ll be more like 170kg on pickup and 200kg when you loaded and ready to go. Make sure that the higher figure is within specs.
4. When hitched, will the addition of TBM push the car’s weight over GVM?
Let’s say you’ve got a 3,000kg GVM and you’ve got everything loaded, now weighing 2,900kg. Your van’s TBM is 180kg. Well, add 2,900 + 180 = 3080kg, and you’re 80kg over. Remember to leave payload room for the TBM!
5. When hitched, will the rear axle load be exceeded?
Same deal for the rear axle load, except that 200kg of TBM might well be more like 250kg added to the rear axle load, with 50kg off the front axle.
6. Will any other weight limits be exceeded?
The most common limits to be exceeded are above, but you may also exceed the GCM or other limits. Refer to the towing weights article.
7. Will you be doing high-stress towing?
The max braked tow capacity is a maximum, and no vehicle is designed to do it day-in, day-out. Particularly not in hot conditions, when modified, slugging up and down hills, or cruising at 100 or 110km/h. If you tow close to the max tow limit and do that sort of work, expect premature failures and increased maintenance.
8. Do you have plans or budget to modify the tow car?
We’ll cover modifying a vehicle to tow in the future. But for heavy towing – at or beyond half of the max braked tow capacity – one must-do modification is suspension. The standard suspension on any vehicle is very much a compromise between a comfortable ride around the ‘burbs with no load and carrying the maximum payload plus heavy towing.
As a result, most suspensions aren’t optimised for heavy towing, and the car’s back end sags even under moderate tow ball masses. This leads to poor handling, impaired braking and steering, and potentially greater tyre wear. So, for any heavy towing, consider a suspension upgrade, which could be a complete replacement, airbags, or just stiffer rear springs. Without it, you may not be able to properly tow anywhere near max capacity.
9. Will you change tow car or caravan in the future?
Buy for the future. If you’re planning on moving from a two-berth to a four, get the tow car you’ll need in the future. Similarly, if you’re going from a four-berth to a two, you might be able to get a less than ideal tow car for the bigger van and just take less gear, and drive more slowly until you downsize.
What else makes a good tow car?
The debate about automatic vs manual transmission is long dead as not only are automatics better, but good luck buying any form of manual 4WD.
What you will find beneficial in a tow car is: