Sizing of wheel trims?

[Jules03]

Does anyone know what dictates the size of wheel trims?

I've just bought 15" wheel trims for my car and it says '15' on my tyres and therefore I was told to get 15" wheel trims.

The wheel trims arrived only to not fit - they are too small - and therefore I was wondering what dictates the size of a wheel trim?

I'm presuming I ordered the right product but was sent the wrong item.

Curiosity question I guess!

Thanks

 

[Stivino]

You might find that they arte just a very tight fit. Give them a good hard push but be careful because aftermarket trims can be very brittle and break easily.

 

[Burnerman]

Typical tyre markings:
195 / 45 15 V
195 = the width of the tyre
45 = the aspect ratio - the distance between the rim and the outer diameter of the tyre
15 = the rim diameter
V = the speed rating of the tyre.
John

 

[Stivino]

The Aspect ratio isn't the distance between the rim and the outer diameter of the tyre, it's the height of the sidewall of the tyre expressed as a percentage of the tyres width.

 

[Burnerman]

Absolutely correct! Its just the bit of the tyre that the layman sees.

 

[mointainwalker]

If you buy after-market wheel-trims the size marked is the same as the wheel, HOWEVER there is no guarantee they will fit.

There are two basic retaining systems for trims; 5 - 6 individual clips or a large steel-ring attached to legs.

Since the makers have no idea what they will be fitted to they try to make them as generally applicable as possible, but there are always designs of wheel that won't take after-market trims.