Van and light commercial tyres are built to carry more weight than car tyres, and their markings say so. The clearest sign is a C after the size, but a van tyre also carries a dual load index and often a ply rating, each describing how much it can safely haul.
The C marking
A commercial tyre shows a C immediately after the size, as in 225/75 R16C. The C stands for Commercial, and it marks a tyre constructed to carry heavier loads at higher pressures than a passenger car tyre of the same size. Vans, light commercials and many caravans and trailers need this stronger construction for the weight they routinely carry.
A related marking, CP, identifies tyres designed specifically for motorhomes and camper vans, which place heavy and often static loads on their tyres.
The dual load index
Car tyres carry a single load index; commercial tyres usually carry two, separated by a slash, such as 104/102. The two figures cover two ways of fitting the tyre:
- The higher number (104) is the maximum load per tyre when used as a single wheel
- The lower number (102) applies when tyres are fitted in a twin or dual arrangement, as on the rear of some heavier vans, where two tyres share each side
For an ordinary van with a single wheel at each corner, and for caravans and single-axle trailers, the higher figure is the one that applies. The matching load in kilograms can be read from the standard load index chart.
Ply rating and load range
Commercial tyres are often described by a ply rating such as 6PR, 8PR or 10PR, or by an equivalent load range letter (load range C, D and so on). The higher the number, the stronger and higher-pressure the tyre.
It is worth knowing that the ply rating no longer means the actual number of layers inside the tyre. Modern materials are far stronger, so an 8PR tyre rarely has eight real plies; the figure is an equivalent-strength rating carried over from older tyre construction. Car tyres sit at the bottom of this scale, while commercial tyres run 6PR and upward.
Why it matters, and C versus XL
A van or load-carrying vehicle needs the commercial or specified rating the maker calls for. Fitting ordinary car tyres to a vehicle that requires C-rated tyres leaves them under-built for the weight, risking overheating and failure.
It is easy to confuse the C marking with the passenger Extra Load (XL) rating. Both are reinforced, but they are different systems for different vehicles: a van that calls for Commercial tyres needs Commercial tyres, not passenger Extra Load, and the door placard states which is required, and the correct commercial-rated tyres are easy to find by entering the van's size at a tyre retailer such as Tyres.co.uk.
Read the two load numbers correctly
Where two load indices are shown, they generally refer to single and dual fitment, not front and rear axles. A van with one wheel at each side of an axle uses the relevant single-fitment specification. Do not confuse an XL passenger tyre with a commercial tyre merely because both sound reinforced. Camper conversions and working vans can have demanding axle loads, so confirm the specification for the completed vehicle and its intended load.
Common questions
What does C mean on a van tyre?+
C stands for Commercial. It appears after the size, as in 225/75 R16C, and marks a tyre built to carry heavier loads at higher pressures than a passenger car tyre, as vans and light commercial vehicles require.
What does a dual load index like 104/102 mean?+
It gives two load ratings. The higher number is the maximum load per tyre when used as a single wheel, and the lower number applies when tyres are fitted as a twin or dual wheel, as on some heavier vans. For single-wheel vans and caravans, the higher figure applies.
What does the ply rating or PR mean on a van tyre?+
Ply rating, shown as 6PR, 8PR and so on, indicates a tyre's load and pressure strength. It no longer means the actual number of plies inside; it is an equivalent-strength rating, with higher numbers indicating a stronger, heavier-duty tyre.
Can I fit car tyres to a van?+
No, not where the vehicle requires commercial tyres. A van or load-carrying vehicle needs the C-rated or specified tyre to handle its weight safely. Fitting passenger car tyres risks overloading them, with the heat and failure risk that brings.