Motorhome advice: Top 10 motorhome and campervan tyre tips
Words by Peter Rosenthal
Tyres are one of the most important safety items on a motorhome. These humble rings of rubber have a truly multi-purpose role. They have to support the weight of the vehicle at all speeds, control body roll in the corners, grip dry tarmac – as well as wet grass, mud and snow – help reduce the transmission of bumps through to the cabin and bring the vehicle safely to a stop from any speed.
As if that wasn’t enough, they also have to do it even if they’re getting baked in summer and frozen in winter. Motorhome and campervan tyres really do have to contend with everything.
Modern tyres have evolved to meet the needs of a modern motorhome. This technology includes a multi-layered carcass to support the weight, tread patterns to optimise grip on wet grass and sidewalls that are resistant to UV degradation and kerb damage. Some even have compounds that vary their properties across the width of the tread pattern, rather than using just a single material.
As tyres have such a critical role in the safety of your vehicle, it pays to choose wisely and know how to look after them to maximise their longevity.
1 Understand the sidewall info
The size of a tyre is specified as a mix of metric width and imperial diameter measurements, with a metric ratio thrown in. Michelin did try to sort out this imperial/metric mismatch in the 1980s by introducing a new line of TRX metric tyres. Sadly, the rest of Europe didn’t embrace this eminently sensible step, so they’re resigned to a footnote in tyre history.
A typical Ducato will use a 225/75R16 tyre, which means it’s 225mm wide and has an inner diameter (measured at the inner mounting flange) of 16 inches. The ‘75’ bit is the aspect ratio and, in this case, means that the tyre’s sidewall height is 75% of the tread width. The R refers to the tyres’ construction type as being a radial ply (on a radial the inner cords run at 90 degrees to the sidewall. On a cross-ply tyre they run at 45 degrees to the sidewall).
You’ll also see some other numerals on the tyre next to the size, such as 116Q. The 116 is the load rating (1,250kg in this case) while the letter is the speed rating (Q is 99mph). So, a 116 load rating means that every tyre – when correctly inflated – is rated to support a load of 1,250kg per tyre (5,000kg for four or 7,500kg for a double tyre or tag-axle).
What your motorhome handbook states is the correct tyre size, load and speed rating is the one you should use. While you can safely opt for a higher load rating number (like 118, which is 1,320kg), the tyre will have a stiffer construction that may not work as well with your suspension and could result in a harsher ride.
Tyres also feature a date code – usually stamped in an oval box – that indicates their build week and year, as well as a maximum pressure rating for the USA. While this doesn’t directly apply to the European market, it’s not wise to exceed it.
2 Legal tyre tread depth
The legal requirement for a tyre used on a road vehicle is that it must be replaced when the tread depth across three-quarters of the tread’s circumference is less than 1.6mm.
This can be measured with a tyre gauge (widely and cheaply available), with most tyres additionally having tread wear indicator blocks. These are fitted in the grooves between the tread blocks and when the tread block is worn level with them, it’s time to replace the tyre. However, it’s wise to replace them before they’re this low – more on this later…
3 Camper-specific tyres
As long as you stick to the correct size, load and speed rating for your campervan or motorhome, you can safely use either van tyres or camper-specific tyres. The latter are a recent development and often have extra reinforcement in the sidewalls to better resist winter lay-up and vehicle weight and have more UV-resistant compounds in them. They also have tread patterns optimised for getting off campsite pitches.
Van tyres tend to be cheaper and are more widely available, while camper-specific tyres can be harder to find as they’re made in batches.
Whichever tyre you prefer, we recommend buying a respected brand such as Michelin, Continental, Pirelli, etc. There are lots of cheap brands on the market and they may not be built to the same standards. If a tyre is half the price of a respected brand, it’s cheap for a reason!
4 Winter tyres and snow tyres
Most motorhome tyres are also rated for mud and snow so can be used in all seasons... up to a point. The M+S symbol means that the tyre has some snow ability but does not mean that it is a winter tyre. Only winter tyres that carry the triple Alpine peak symbol with a snowflake are tested to provide a certain grip level in snow.
If you’re planning to visit a Nordic country or like touring Scotland in winter, you should consider winter tyres. The cut-off point tends to be around 7˚C – below this figure you’ll find that a dedicated winter tyre is the thing to have.
All the top brands offer winter tyres (Michelin Agilis X-Ice North, Continental ContiWinterContact and Pirelli Carrier Winter) for large vans. The key difference is a compound designed to work below 7˚C mated up to treadblocks that have more sipes in them (thin wavy lines designed to cling on to ice roads).
Having experienced both types of tyre, winter tyres are definitely superior at low temperatures. I’d rather have winter tyres than four-wheel drive in snow, but both would be best!
You can use winter tyres all year round, but they are noisier and will wear out faster on dry roads, so it’s best to get an extra set of steel rims to mount them on. Ideally, you’d want to swap to winter tyres in November and then back to normal tyres in February or March (as many motorhomers do in European countries).
5 Economical tyres
A recent entrant to the tyre market are tyres claiming green credentials. While eco tyres can, in theory, save you fuel thanks to their lower rolling resistance, this is only the case if you carefully monitor and use only the correct tyre pressure. They also may not be ideal for getting off a slippery campsite pitch.
If you only ever use hardstanding pitches and never venture off tarmac roads, then they may be worth looking at but, if you want a tyre that is better suited to the variety of ground surfaces that a typical motorhome experiences, then there are better choices of tyre.
6 Weight and the correct tyre pressure
Unlike a road car or van that has the tyre pressures stamped on the door jamb, the handmade nature of a motorhome throws up a few variables when it comes to finding the correct tyre pressures. Not all makers update the original tyre pressure label for the original van so this can’t be relied on.
The other variable is the weight of all your touring equipment and any accessories you’ve had added to the motorhome. Anything that is bolted to the vehicle or enters it via a hatch or doorway must be taken into consideration for weight.
While you could weigh all these items individually, it’s safer and easier to visit a weighbridge. These will either be listed under ‘weighbridge’ online in your local area or will often be found at scrapyards and farms.
You’ll need to visit one of these (ring to find the best time to visit) and get the front axle and rear axle (or axles if you have a tag-axle model) weighed individually. Check this weight is under your maximum axle limits for the front and rear axle of your motorhome (see the manual or chassis plate details).
If this all sounds like a lot of fuss, here’s a thought: as a driver you are legally responsible for knowing the weight of your vehicle and, if it’s found to be overladen, you can be fined and/or given penalty points on your licence. It’s worth noting that VOSA uses technology that weighs your vehicle when it’s in motion. So, it’s better to check it first.
If you are overladen and emptying the water tanks and thinning down your touring kit isn’t enough to solve it you might need to look at replating your vehicle (see svtech.co.uk) or consider replacing it.
7 Setting the tyre pressure
Once you’ve obtained the weight of your motorhome, contact the manufacturer of the tyres and ask for its pressure recommendations. You need to set the tyre pressures when the tyre is cold (when it’s hot after a motorway run, the heated air will increase the pressure).
Armed with these numbers, use an airline to inflate the tyre past the desired pressure, then use an accurate gauge with a bleed-off valve to gradually lower the pressure until it is perfect. If you have a tyre pressure monitoring system (TPMS) reset it to these new pressures.
It’s worth checking these pressures every few weeks, or at least before any long journeys, as tyres will naturally lose a little pressure over time (especially with a 3.5-tonne motorhome on top of them).
Valves often get mentioned in regard to motorhomes and the key point here is that motorhomes based on large vans (such as the Fiat Ducato) or a truck chassis (like Iveco) need to use suitably rated tyre valves that are designed to cope with the correct pressure. These may be in rubber or metal but must be rated for a high enough pressure and specifically designed to fit the vehicle’s steel or alloy wheel.
8 Carrying a spare tyre
Not all new motorhomes come with a spare wheel or tyre – it’s likely that an extra 50kg of payload or an electronic gadget is more likely to tempt you into buying a new motorhome or campervan. The reality is that spare wheels just aren’t very sexy in marketing terms.
This is a shame because they really are a vital bit of kit in the event of a tyre getting damaged. While tyre sealant and an inflator can deal with punctures from items such as thorns, nails and screws, for any hole above the size of a pea, they’re pretty useless and you’ll need a replacement.
During normal business hours you can often find tyre stockists that will stock a suitable replacement, but outside of regular hours you may struggle. Equally, few retailers stock a wide range of camper-specific tyres so, if you want a certain brand, you may have to wait days to get it.
So, always check to see if a new motorhome has a spare wheel and, if not, ask if one can be added.
If you’re really tight on payload and/or you can’t carry a spare wheel, then it’s well worth buying a spare tyre and keeping it onboard. This is especially worth doing if you use camper-specific tyres.
9 Alloy upgrades
Many motorhomes now come with alloy wheels. But if you have a model with steel wheels and want to change to alloys, then when your tyres need replacing is the ideal time to do this.
If the new alloy wheels’ diameter is greater than the previous wheels’ diameter then this has to be accompanied by a similar decrease in the sidewall depth of tyres so the rolling radius remains the same as the original set-up. This ensures the speedo reads correctly.
While swapping from 15in to 16in tyres will have minimal effect on ride comfort, going for significantly larger diameter wheels will mean using low-profile tyres. These give a harsher ride, are more prone to bending the alloy if you hit a pothole and will limit your tyre choice. You can get away with larger wheels on VW Transporter-sized vans, but not on larger Fiat Ducato-sized vans.
It’s also important to fit wheels that have a suitable load rating for your vehicle and that they fit correctly.
The wheels must have the correct centre bore (the hub on the vehicle that supports the load running through the wheel) and the correct bolt diameter and mounting arrangement (called the PCD – pitch circle diameter). Alloy wheel bolts are usually different to steel wheel bolts, too, so the correct bolt must be used.
For this reason, we’d suggest you stick to manufacturer-approved alloy wheels or go via a motorhome wheel specialist such as tyremen.co.uk which specialises in load-rated TUV-approved alloys.
10 Replacing tyres on a motorhome and campervan
Conventional wisdom says you should replace tyres after five or six years. However, some modern tyre makers point out it’s not that simple and depends on how the tyre has been looked after.
Tyres kept in the shade or inside and those that are fitted on lighter motorhomes will last longer than those used continually or left in full sun and fitted to a heavy motorhome.
As many motorhomes do low mileages, it’s often the case that the tyres start to degrade – with the appearance of cracks or bulges – long before the tread depth has worn down.
Once the tread depth is below 3mm, the performance in the wet (and on grassed pitches) is diminished and it’s worth considering replacement.
Equally, tread or sidewall damage – such as bulges, cracks, frayed rubber, cords showing through or treadblocks missing – mean it’s time for replacing.
About 90% of the materials in tyres are recycled each year and they can also be used as rubber crumb in carpeting and safety flooring.
Always recycle old tyres at a tyre centre, so that they can remain part of this recycling process.
This article was originally published in the March 2020 issue of MMM - the motorhomer's magazine. To buy a digital version of that issue, click here.