Tyre classification systems

Classification name Example Nominal diameter Nominal section width Nominal rim diameter
Type III 8.50-10   8½ in 10 in
Type VII 49x17 49 in 17 in  
Three Part 49x19.0-20 49 in 19.0 in 20 in
Radial 32x8.8R16 32 in 8.8 in 16 in
Metric 670x210-12 670 mm 210 mm 12 in