Vehicle care 161■ Replacement tyres or wheels donot match the original equipmenttyres or wheels. Tyres and wheelsother than those recommendedcould prevent the tyre pressuremonitoring system from functioningproperly.■ Operating electronic devices orbeing near facilities using radiowave frequencies similar to the tyrepressure monitoring system couldcause the tyre pressure monitoringsystem sensors to malfunction.If the tyre pressure monitoring systemis not working properly, it cannotdetect or signal a low tyre condition.Seek the assistance of a workshop.Tread depthCheck tread depth at regularintervals.Tyres should be replaced for safetyreasons at a tread depth of 2-3 mm(4 mm for winter tyres).The legally permissible minimumtread depth (1.6 mm) has beenreached when the tread has worndown as far as one of the tread wearindicators (TWI). Their position isindicated by markings on thesidewall.If there is more wear at the front thanthe rear, swap round front wheels andrear wheels periodically. Ensure thatthe direction of rotation of the wheelsis the same as before.Tyres age, even if they are not used.We recommend tyre replacementevery 6 years.Changing tyre and wheelsizeIf tyres of a different size than thosefitted at the factory are used, it may benecessary to reprogramme thespeedometer as well as the nominaltyre pressure and make other vehiclemodifications.Ensure that the direction of rotation ofthe wheels is the same as before andaccording to tyre manufacturerinstructions.After converting to a different tyresize, have the label with tyrepressures replaced.9 WarningUse of unsuitable tyres or wheelsmay lead to accidents and willinvalidate the vehicle typeapproval.
