Circuit
GT, Britcar, Sportscar & Group C
| Size | Overall Width Category (F = Front / R = Rear) | Design Rim Width | Diameter | Overall Width | Tread Width | |||||
| 12" | 14" | 16" | inch | mm | inch | mm | inch | mm | inch | |
| 210/640R18 | F 7.5-9 | 8 | 640 | 25.2 | 223 | 8.8 | 203 | 8 | ||
| 235/640R18 | F 8.5-10 | 9 | 640 | 25.2 | 248 | 9.8 | 228 | 9 | ||
| 250/640R18 | F 9-10.5 | 9.5 | 640 | 25.2 | 257 | 10.1 | 240 | 9.5 | ||
| 260/640R18 | F 9.5 - 11 | 10 | 641 | 25.2 | 270 | 10.6 | 252 | 9.9 | ||
| 285/650R18 | F 10.5-11 | F 11-12 | 11.5 | 644 | 25.4 | 306 | 12 | 284 | 11.2 | |
| 300/650R18 | F 11.5 - 12.5 | 12 | 645 | 25.4 | 320 | 12.6 | 301 | 11.9 | ||
| 265/660R18 | F 10-11 | 10 | 655 | 25.9 | 278 | 10.9 | 252 | 9.9 | ||
| 280/660R18 | F 10.5-11 | F 11-12 | 11 | 658 | 25.9 | 304 | 12 | 274 | 10.8 | |
| 285/660R18 | F 10.5 -11.5 | 11 | 655 | 25.8 | 301 | 11.9 | 277 | 10.9 | ||
| 300/660R18 | F+R 12-12.5 | 12.5 | 656 | 25.8 | 321 | 12.6 | 290 | 11.4 | ||
| 340/660R18 | F 13-14 | 13.5 | 656 | 25.9 | 355 | 14 | 324 | 12.8 | ||
| 285/680R18 | R 10.5-11 | 11 | 679 | 26.7 | 302 | 11.9 | 270 | 10.6 | ||
| 290/680R18 | R 10.5-11 | 11 | 680 | 26.8 | 302 | 11.9 | 281 | 11.1 | ||
| 330/680R18 | ||||||||||
| 270/710R18 | R10.5-11 | 11 | 708 | 27.9 | 299 | 11.8 | 258 | 10.2 | ||
| 275/710R18 | ||||||||||
| 310/710R18 | R 12.5-13 | 13 | 711 | 28 | 354 | 13.9 | 305 | 12 | ||
| 315/690R18 | R 12.5-13 | 13 | 691 | 27.2 | 351 | 13.8 | 307.5 | 12.1 | ||
| 360/710R18 | R 14.5-15 | 14.5 | ||||||||
| 360/725R18 | R 14.5-15 | 14.5 | 720 | 28.3 | 402 | 15.8 | 360 | 14.2 | ||
Single Seater
| Size | Construction | Pattern | Permitted Rim Width | Optimum Rim Width | Diameter | Overall Width | Tread Width | Revs Per Mile | |||
| inch | inch | mm | inch | mm | inch | mm | inch | @100mph | |||
| 140/535R13 | S04/S04W | slick/wet | 5.5-7.0 | 5.5 | 535 | 21.1 | 169 | 6.7 | 140 | 5.5 | 957 |
| 160/535R13 | S04/S04W | slick/wet | 6.0-8.0 | 6.5 | 537 | 21.1 | 189 | 7.4 | 160 | 6.3 | 826 |
| 175/535R13 | S04/S04W | slick/wet | 6.0-8.0 | 7.5 | 539 | 21.2 | 206 | 8.1 | 175 | 6.9 | 950 |
| 190/535R13 | S04/S04W | slick/wet | 7.5-9.5 | 8 | 541 | 21.3 | 221 | 8.7 | 190 | 7.4 | 946 |
| 205/570R13 | S04/S04W | slick/wet | 8.0-9.5 | 9 | 574 | 22.6 | 255 | 10 | 205 | 8.1 | 892 |
| 230/570R13 | S04/S04W | slick/wet | 9.5-10.5 | 10 | 575 | 22.6 | 280 | 11.2 | 235 | 9.2 | 890 |
| 230/535R13 | S04/S04W | slick/wet | 9.5-10.5 | 10 | 541 | 21.3 | 262 | 10.3 | 231 | 9.1 | 946 |
| 280/570R13 | S04/S04W | slick/wet | 11.5-12.5 | 12 | 575 | 22.6 | 335 | 13.2 | 285 | 11.2 | 890 |
Miscellaneous
| Size | Construction | Pattern | Permitted Rim Width | Optimum Rim Width | Diameter | Overall Width | Tread Width | Revs Per Mile | |||
| inch | inch | mm | inch | mm | inch | mm | inch | @100mph | |||
| 160/490-10 | D15 /D42 | slick/wet | 5.0-7.0 | 6 | 480 | 18.9 | 214 | 8.4 | 150 | 5.9 | 1067 |
| 180/490-10 | D15 /D42 | slick/wet | 6.0-8.0 | 7 | 485 | 19.1 | 230 | 9 | 170 | 6.7 | 1067 |
| 170/510-13 | Clubmans | slick/wet | 7.0-9.0 | 8 | 516 | 20.3 | 222 | 8.7 | 165 | 6.5 | 992 |
| 210/570-13 | Clubmans | slick/wet | 7.0-11.0 | 10 | 564 | 22.2 | 283 | 11.1 | 210 | 8.3 | 908 |
| 160/490-13 | D104 | slick/wet | 4.5-7.5 | 6 | 492 | 19.4 | 188 | 7.4 | 156 | 6.1 | 1041 |
| 180/490-13 | D104 | slick/wet | 5.5-8.0 | 8 | 497 | 19.6 | 222 | 8.7 | 179 | 7.1 | 1030 |
| 215/525-13 | D104 | slick | 9.0-11.0 | 10 | 525 | 20.7 | 270 | 10.6 | 215 | 8.5 | 975 |
| 240/525-13 | D104 | slick | 10.0-12.0 | 11 | 531 | 20.9 | 274 | 10.8 | 234 | 9.2 | 967 |
| 305/600-13 | D104 | slick | 12.5-14.0 | 13.5 | 607 | 23.9 | 402 | 15.8 | 305 | 12 | 845 |
| 210/600-16 | D104A | slick | 7.5-9.5 | 8.5 | 600 | 23.6 | 255 | 10 | 215 | 8.5 | 854 |
| 275/600-16 | D104 | slick/wet | 9.0-12.0 | 10 | 610 | 24 | 319 | 12.6 | 284 | 11.2 | 839 |
| 310/625-16 | D104 | slick/wet | 11.0-14.0 | 12 | 620 | 24.4 | 343 | 13.5 | 310 | 12.2 | 826 |
| 350/650-16 | D104 | slick | 14.0-15.0 | 15 | 648 | 25.5 | 408 | 16.1 | 354 | 13.9 | 791 |