Vehicle safety can be severely compromised by the fitting of incorrect or oversized wheels and tyres. There are strict guidelines as to what extent a driver can increase the size of wheels and tyres. Many motorists do not realise the effect of fitting incorrect tyres and wheels until it is too late, while others flout the law intentionally. This practice is not only illegal but dangerous. Dealers, tyre retailers or workshops who fit wheels and tyres that do not conform to the law are leaving themselves open to litigation if an accident is attributed to illegally fitted wheels and tyres.

 The maximum allowable track increase is:

• in the case of a front axle - 25 mm;
• in the case of a rear axle with independent suspension - 25 mm;
• in the case of other rear axles - 50 mm; and
• in the case of a motor vehicle manufactured with a combination of front wheel drive, McPherson strut front suspension and negative scrub radius steering geometry, no increase in wheel track is permitted unless specified by the vehicle manufacturer.
• in the case of a motor vehicle fitted with a diagonally split braking system (i.e. one front wheel and opposite rear wheel on same hydraulic circuit) no change in the wheel track dimension is permitted.
• Spacers between the wheel and hub are not permitted unless provided by the vehicle manufacturer as original equipment.