The essential guide to 4×4 and caravan tyres

Caravan tyres and 4×4 tyres might not be sexy, but they are vital for touring safely and reliably. It’s a cliché, but tyres are the only contact between your vehicle/caravan/trailer and the road. So, knowing as much about them as possible is vital.

There are three main types of tyre patterns used on 4×4 and caravan tyres: Highway Terrain (H/T), All-Terrain (A/T) and Mud-Terrain (M/T) tyres. There are also three main types of tyre construction: Passenger, Commercial and Light Truck. Caravans tend to come with Commercial tyres, A/Ts or M/Ts.

Caravan and 4×4 tyre types explained

Let’s look at the benefits of each tyre type.

Highway Terrain tyres

Highway Terrain tyres are relatively quiet and smooth and typically last longer than other tyre types. They have a high-speed rating and relatively light sidewall construction. With a tread pattern like a ‘car’ tyre, these tyres provide the best on-road traction for your caravan or 4×4. Highway Terrain tyres are fitted to most new 4×4 wagons and some 4×4 utes too, and are marked as Mud and Snow (M+S) tyres, which relates to their tread pattern being slightly more open than a regular passenger-rated tyre. If you restrict yourself to on-road driving and towing, then H/T tyres will do the job fine.

All-Terrain tyres

What exactly defines an A/T tyre depends on how the tyre manufacturer has designed it. Some A/Ts will offer a tread pattern and carcass construction similar to a H/T tyre, while others will have a more aggressive (blocky) tread and stronger construction closer to an M/T. Often the A/T tyre will be marked as ‘M+S’, which means it has a more open tread pattern than a standard passenger tyre.

Mud-Terrain tyres

Mud-Terrain tyres are the heaviest choice for your caravan or 4×4. They have a stronger construction and feature a blocky, deep tread pattern. They also have a low-speed rating and a high load rating. Their tread pattern is designed for biting through mud, and they offer good grip in other off-road situations, such as climbing rock steps.

Passenger-rated tyres

Of the tyre construction types, Passenger-rated tyres are the least puncture-resistant but are also the lightest and often cheapest to buy. In addition, Passenger-rated tyres have the highest speed rating. Some H/T tyres are P-rated. You can tell because you will see a ‘P’ prefix on their tyre size (written on the tyre itself), such as P225/75R16.

Light Truck

Light Truck (LT) tyres for your caravan or 4×4 have a stronger carcass so that they can meet the load requirements of light trucks. But how puncture-resistant they are can vary. Light Truck tyres are available in A/T, Commercial and M/T tread patterns.

Commercial

As the name suggests, LT Commercial-rated tyres are intended for commercial vehicle applications where the vehicle’s high load-carrying requirements necessitate a heavier construction tyre. They usually have a simple on-road or sometimes a more open Mud and Snow tread pattern and don’t have a high-speed rating. Their heavier construction gives a higher load rating and better puncture resistance than passenger tyres, making them ideal for heavier caravan tyres. Identify these tyres by a ‘C’ suffix in their tyre size, for example, 185R14C.

The best compromise – for your 4×4 tow vehicle tyre

An All-Terrain tyre in LT construction is a good compromise for your 4×4 tow vehicle for both on-road driving and towing off-road. While A/T tyres typically have a lower speed rating than an H/T tyre — often between T and H – this is still beyond the highest speed you can legally tow at (see speed-rating chart below). They also have a higher load rating and more open, aggressive tread pattern for better off-road performance.

A/Ts will have a more puncture-resistant, more robust construction too. Check the tyre specs online or on the tyre sidewall — eight- or 10-ply ratings are best for protection against stone damage and sidewall staking.

If you’re going to be slipping and sliding on a muddy track, a good A/T tyre is going to do as good a job of keeping the van straight as an M/T in most situations. If you’ve got the trailer trying to jack-knife on soapy mud, then you’d have to ask yourself why you’re dragging it through there in the first place.

Caravan tyre – Mud vs Commercial vs All-Terrain

Many on-road caravans are fitted with Commercial-rated tyres, and they are the best compromise for such a van in terms of having sufficient load rating, cost, and offer an improvement in puncture resistance over P-rated tyres.

Mud Terrain tyres on a caravan are overkill for most tourers. They often cost more than other tyre types, their added rolling resistance will add to towing fuel consumption, and they offer less grip on the road – especially in the wet. As they are not driven wheels, the little off-road grip advantage in having M/Ts instead of A/Ts on a caravan can be felt in lateral traction. For more about that, read our article on the case for Mud-Terrain and All-Terrain caravan tyres.  

Match fitness

When touring in remote areas, it is useful to have your 4×4 and caravan fitted with matching wheels and tyres. If you get several punctures or damaged tyres or wheels, you have more than one spare to go around to suit either vehicle or van. This set-up requires a trailer to be fitted with the same stud pattern, offset and tyres with the same rolling radius as the tow vehicle.

Sizing up the options

You can increase overall tyre diameter by up to 25mm legally, which gives improved ground clearance and often increased tyre options. Check out tiresize.com to see what you can increase tyre size to legally.

The writing on the wall

The sidewalls of your 4×4 and caravan tyres contain lots of useful information about the tyre size, speed rating, load rating, and even how it should be balanced.

Join the dots

Wondering what the red and yellow dots mean on your brand-new set of 4×4 or caravan tyres? When tyres are made, they are not perfectly balanced nor perfectly round. The red dot on the tyre sidewall marks the point where the tyre is the lightest on its radius, and therefore the tyre fitter should align this mark with the wheel’s tyre valve — which is the heaviest part of the wheel. When the tyre is fitted this way, it will need fewer weights to balance it.

The yellow dot marks the tyre’s high point — and this mark should be aligned with an indent on the wheel, which marks its low point (because wheels are not made perfectly round either).

Reading between the lines

Tyre manufacturers say that tyres only have a useful life of between five and six years before the rubber deteriorates and becomes dangerous. That means the risk of a total tyre failure on your 4×4 and caravan — a blow-out — increases exponentially as the tyre reaches five years old, regardless of the amount of tread remaining. To find out how old your tyres are (or how long your new set of tyres have been lying around), look for a four-digit code on the tyre sidewall corresponding to the week and the year it was made. For example, a 4718 code means the tyre was made in the 47th week of 2018.

Ratings matter

Like many components on your 4×4 and caravan, tyres are designed to take a maximum weight, and legally, their load rating must meet or exceed the Gross Vehicle Mass of the vehicle or Gross Trailer Mass of the van. When replacing tyres (or if you’ve just bought a used tow vehicle or van), check the ratings are correct. For example, if your tandem-axle van has a GTM of 2000kg, each of the four tyres should have a minimum index number of 90 (equating to a 600kg load rating for each tyre).

Roll them around

Tyre rotation is essential to even out tread wear, especially for the 4×4 tow vehicle, which will make the tyre set last longer and should be performed every 10,000km. You want to rotate tyres so they wear evenly, and you’re not left with tyres that have tread remaining but are too old to use (see above). Provided the tyres are all the same size with the same load rating, the spare is fitted to the right (driver’s side) rear, and the (passenger side) left front becomes the spare. The right rear goes to the right front, which goes to the left rear. The left rear moves to the left front.

Reduce pressures

When touring on outback dirt roads with your 4×4 and caravan, drop tyre pressures to around 25psi. The less stiff, more flexible tyre carcass will reduce the chance of tyre punctures. While you shouldn’t tow at more than 80km/h on dirt anyway (due to the reduced grip and because of the damage you can do shaking gear around in your caravan), this is especially relevant when you’ve dropped tyre pressures as heat build-up in the tyres will risk a tyre blow out. Remember to re-inflate tyres to recommended pressures before returning to sealed roads.

 How to read a sidewall

Three types of size descriptions are used on 4X4 and caravan tyres. For example:

265/65R17 100T

• 265 = section width in millimetres
• 65 = sidewall aspect ratio, as a percentage
• R = tyre construction, in this case, radial
• 17 = rim diameter, in inches
• 100 = load rating (in this case 800kg)
• T = speed rating (in this case, 190km/h).

9.50R16LT

• 9.50 = width in inches
• R = tyre construction, in this case radial
• 16 = rim diameter, in inches
• LT = light truck construction

32×11.50R15 LT

• 32 = diameter of tyre mounted on rim, in inches
• 11.50 = section width, in inches
• R = tyre construction, in this case radial
• 15 = rim diameter, in inches
• LT = light truck construction.

Read the placard

A tyre placard is a plate or sticker that, by law, must be fitted to vehicles and caravans with the tyre sizes designed for the vehicle and the minimum speed and load ratings for those tyres. These are considered the legally correct specification tyres for your vehicle. You can usually find the tyre placard stuck on somewhere like a door jamb or aperture, fuel filler flap or glovebox lid on your vehicle and the compliance plate for your van, usually fitted to either the boot, door entry area or A-frame.

Top tyre tips

• Before leaving home or camp, always check that both vehicle and van tyre pressures are at recommended levels.
• Check tyre treads and sidewalls for damage or uneven wear regularly.
• Brush the back of your hand over each tyre when pulled up after a highway run. If the tyres are excessively hot it indicates that you may be running too-low a tyre pressure (or there’s a brake or bearing issue).

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