Slide On: Which Vehicle 

What Vehicle Do You Need For A Slide-on?
One of the major benefits of caravanning is you can unhitch the van and your vehicle is free for other uses. Same with a slide-on... but not quite the same.

The main difference with a slide-on, for at least the far majority of campers, is you need a tray on the back of your ute. That's ideal if you are a tradie or a farmer. But for everyone else, how do you make the most of a tray for everyday use. One option is to fit a canopy on the back to make more like an SUV sedan.

For the Australian slide-on campers listed in the table at the beginning of this section, these are designed for Australia’s popular four-wheel drives, including the Mazda BT-50, Ford Ranger, Isuzu Dmax, Toyota Hilux and Toyota Landcruiser.

If you have a tub on the back of your four-wheel drive, you can swap the tub for a tray. You will see on closer inspection, the tub is actually quite separate to the cab. Looks all part of the same vehicle, but there’s probably only a half a dozen bolts holding the tub to the chassis. Which means it’s relatively simple to take off. Sadly, don’t expect to get much for your tub – maybe a hundred or so dollars at best. Mounting a tray generally costs a few thousand dollars. Weight is a big consideration. A strong alloy tray is preferred as it is much lighter than a steel tray.

Payload
One of the biggest issues of a slide-on is weight. The four-wheel drives mentioned above, typically have a payload of around 1000kg. Sounds a lot, but before you consider the weight of your camper, you need to consider the weight of fuel, water, passengers, bull bar, tow bar, luggage, and other accessories. You can expect that to take up close to half the payload, leaving the rest for your camper.

One of the lightest camper’s dry weight – that is the weight out the factory door before you fill the water tank, add food and drinks, etc, are about 400kg. That leaves you about 100kg left – the weight of just 100 litres of water. So don’t pack too much food or think about taking bikes or spare tyres. The point is, weight is a huge factor. A GVM upgrade will increase your payload by about 300Kg which will generally keep you in the safe zone.  The bottom line is you need to carefully consider the type and therefore the weight of the camper you choose.

Type of four-wheel drive - Dual, Single, Extra Cabs
Another important consideration is the type of four-wheel drive – dual cab, space cab or single cab. I often find it interesting observing the new vehicles being offloaded on the wharf. As you will see on the road, there’s no surprise dual cabs far out way other models. They are practical – tradie by day, family car thereafter. But when it comes to a slide-on, there’s another important consideration.

Next time you are out, have a look where the rear wheel is on a dual cab. You’ll note it’s right at the front of the tray or tub. Which means when you load the tray to its maximum with the likes of camper box, most of that weight is on the overhang past the rear wheel axle. A GVM upgrade will increase the allowable weight, but it doesn’t increase the structural strength of the chassis.

Head off into the outback and put your vehicle through some rough and bumpy terrain where the back will be wanting to bounce up and down, and you will be testing your chassis to the max. If you are towing boat…. because you can, just imagine the extra bouncing strain that will be added right on the back of the chassis.
Not surprising, if you google “bent chassis slide-on camper”, then click images, you will be see what I mean.
That’s why Nissan Navaras or Mitsubishi Tritons are not recommended as they are generally regarded as having a chassis of lesser structural strength.

The golden rule is to ensure all the heavy weight, such as water tanks, heavy batteries, extra spare tyres, etc are mounted as far forward as possible over or towards the rear axle. That is, to the front of the tray near the cab.

As such consider carefully using a dual cab with a camper on the back. If you don’t intend to push the limits of your vehicle and stay away from rough terrain, or simply take your time, you’ll possibly be quite safe.

No doubt the safest option is to use a single cab. You’ll note the rear axle is close to the middle of the tray, which means the axle sits right under the middle of the load. The next best option, and one which is generally considered a realistic compromise is a space, freestyle or extracab, where once again, the axle is centred closer to the middle of the tray.

Trays
An alloy tray is definitely recommended over a steel tray, for one primary reason – keeping the weight down. Weight is the biggest issue for a slide-on, unless you’ve got a truck. With a truck the general rule seems to be the opposite, how much weight can I load the truck. But for your average four-wheel drive ute, it’s about keeping the weight down.

An advantage of a slide-on camper over a motorhome style camper where it’s fixed to the chassis, is storage. Under the tray offers a considerable storage opportunity. In general there is enough space for about 80 litres of water storage plus a compartment of sufficient length to store long items such the camper legs. Space behind the rear mudguards can be used for “rope boxes”. These are lockable boxes that can be used to store vehicle related items such as ropes, recovery equipment, compressor, wheel blocks, etc.

The tray dimensions should ideally suit the manufacturers specifications of the camper, but in general, your average slide-on can be mounted on an average tray. For exampe, for an Active Camper the tray should be between 1770mm – 1925mm wide. The length can vary.
A slide-on camper on top of your utility is considered to be a ‘load’ and therefore does not attract any registration fees. Any load on a vehicle is permitted to protrude or overhang within specific legal limits. For your utility and slide-on camper, this limit has been determined as 60% of your wheelbase (the distance between the centre axles of your front and back wheels). The rear overhang distance starts from the centre of your rear wheel and extends behind your utility as shown above. The height of the camper overhang would ideally be about 50 -100mm above the cab.

Bigger Payload Vehicles
Of course, there are always better solutions. You could spend many thousands of dollars to extend the tray to add another rear axle, converting your vehicle to a six wheeler. Or buy an American pickup truck, their version of our utes, such as the Dodge RAM or Ford F250/350 where the payloads are not dissimilar to a light truck.

Or, get a four-wheel drive truck, the Iveco 4x4 Daily or Isuzu trucks being common choices. They are certainly much more expensive options. Given their more limited market, when it comes time to sell, you could expect a longer sale period.

Centre of Gravity – High High Can You Go?
Now you could stack the biggest slide-on you can find on the back of your tray. If it fits under most bridges and is under your legal weight level, you’d be sure to have a home full of comforts. But if you are half serious about going remote or just off road, height matters. In particular, it’s the height of the weight.

The serious off road campers, like the Jackson, specifically maintain a low roof line, when closed, for that very reason. Generally they may be only 80 – 160mm above the vehicle cab height. This keeps the centre of gravity down low compared to everything else, which is very important for off road and even just cruising through soft sand or windy tracks. As Stuart Peddle from Jacksons explains, “this makes a huge difference – you don’t have to be out rock hopping to appreciate it.” The other advantage of being closer down to the vehicle cab are the wind drag benefits.

Vehicle/Camper Package
If you don’t have the right vehicle now, you have two buying choices to make: the camper plus the ute. It’s not that dissimilar to the caravan market. Many people after choosing their ideal van, then realise they need to upgrade to a vehicle with the right towing capacity.
Unlike a motor home where the decision is made for you, as it comes complete. No decisions required. Some slide-on campers like Wedgetail, are now going down a similar route by selling literally a turnkey solution of their camper already fitted to a properly spec’d vehicle. Makes sense. Not all of us are tradies, delivery guys or farmers that have a tray back ute eady to slide the camper onto.