Choosing and Fitting Car Wheel Trims
When looking for car wheel trims, the first thing that will determine your choice of trims is size. The different sizes of wheel trims are informed by the size of the car’s steel rims. But if you are buying the wheel trims yourself and do not have the luxury of a mechanic to advise you, you will quickly realize that the size of the steel rims may not always be obvious by simple observation. Many steel rims will not conspicuously indicate the size of the rims on the surface.
A better approach would be to use the car’s tyres since the tyre’s radial dimensions must correspond with that of the rim. And unlike the rims, the size of the car tyres is prominently embossed on the tyre surface. Tyre radial sizes will be preceded by an R so you have R13, R14, R15 and so on. Purchase wheel trims that correspond with the radial size of your tyres.
But buying the correct size of trims is no guarantee that they will snugly fit onto the steel rims. Like any mechanical device, there are sometimes small but significant differences between the rims from any two manufacturers even though the stated radial size may be the same. If the steel rims are a slightly larger or smaller fit than the trims, then the trims are likely to crack during fitting and/or fall off when the car is in motion.
This is why test fitting the caps before you buy the set is ideal. Make sure the trim snap fits onto the rim and that it is very difficult or near impossible to remove with your bare hands.
As you fit the car wheel trims, you must ensure that there is no lubrication around the rims edge - more so the points where the tabs of the trims will be mounted. In particular, tyre polishing products may contain lubricants such as silicone which would make it hard for the trims to hold. Some steel rims are also coated with a thick, glossy paint and this can have the same effect as lubricant.
In such instances, the rims should be cleaned and wiped completely dry. Water and ordinary soap may not remove the oily lubricant traces - thinner or alcohol is usually more effective. If the trims had already been fitted before the rims were wiped, the trims tabs should be wiped too in order to remove any lubricant residue that may be lodged on the tabs. If the problem is glossy paint, use sand paper to increase the coarseness of the contact points on the steel rim.