Tyres

Tyres are probably one of the most important maintenance items on your vehicle, and they can quite literally save your life and those of your passengers. For this reason great care should be taken in choosing the correct tyres for your circumstance. You CANNOT rely on the existing tyres, the tyre company or the tyre fitter to ensure you have the correct tyres on your vehicle, so make sure you understand the numbering and ratings used and satisfy yourself that everything is correct.

IMPORTANT: If you have tyres in poor condition or of insufficient load rating or speed rating, you risk them exploding whilst driving which for a large vehicle can be catastrophic, and seriously injure people. As if that wasn't enough of an impetus to get it right, then consider that your insurance would almost certainly be invalidated by using poor or incorrectly rates tyres, leaving you personally responsible for any costs, claims, and liable to criminal prosecution for amongst other things, Gross Negligence Manslaughter, Causing death by driving while unlicensed or uninsured and Dangerous driving.

To the right we can see a typical Motorhome Tyre, in this case we can make out the following information…

225/75R16CP

Translated that means

• 225 is the tyre width in mm measured from the sidewall to sidewall.
• 75 is the aspect ratio, in this case the distance between the edge of the rim and the tread is 75% of its width (225 above), so in this case it would be 168.75mm
• R means Radial, and this is the construction of the tyre.
• 16 is the size of the wheel upon which the tyre will be installed, unfortunately its in Inches and in this case its 16“
• CP indicates a Commercial Tyre (C = Commercial P = Private). This can be C for standard light commercial or even absent for smaller vans and cars.

You will also notice 116Q so let's break that down because its REALLY IMPORTANT

• 116 is the load rating of the tyre, I'll include a load rating chart below and we'll discuss load rating there.
• Q is the speed rating of the tyre, I'll also include a speed rating chart below and will also discuss this there.

The Speed Rating is the maximum speed that the tyre can safely withstand. Anyone with any basic understanding of physics will understand that as a tyre spins faster the forces on it increase and at some point it will explode, the speed rating ensures that the tyre can withstand the maximum speed you intend to do. For a motorhome or campervan this would seem immaterial but actually its not and selecting a suitable speed rating is really important. Don't select a K rated tyre at 68mph and then engage warp drive on the motorway when you're late. In our case we've got a Q which is 100mph and is more than sufficient as the only way our Motorhome could do 100mph is in freefall.

Load Rating, is by far the most important value when selecting a tyre. You MUST ensure that your tyres are correctly load rated based on the axel weights (See Weights and Plates) for each wheel. You can mix and match based on axel weight BUT at all times the load rating must be in excess of the kerbside weight on any given tyre.

In our case, our axel weight on the front axel was 2100Kg, so that's 1050Kg per wheel so we must have tyres that can support at least 1050Kg which from the table below means we need a 110 or higher to be safe. Our rear axles were 1500Kg so that's 750Kg per wheel which means on the rear we need at least a 99 or higher. In reality its not really worth mixing load ratings on the vehicle and its better to just go for the same all round. Again in our case this would be 110 or higher but yours will almost certainly be different.

Tyres (also Mobile) in Nottinghamshire