Sorento's front wheels

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i'm not advertising or making any claims for any specific product...just did a yahoo keyword search for "aluminium wheel pitting auto".

Many cast aluminum wheels like those on the Sorento are coated with a clear acrylic coating in order to prevent pitting. There is a possibility that what you could be experiencing is from either the clearcoat on the wheels not being applied, not applied properly, or something happened to make it fail. I'm sure that there are any number of products or processes that will either remove the pitting or remove the brake dust build-up in the pitting, but to prevent it from continuing I think you will most likely have to have the wheels shot with another coat of sealant, otherwise it's just going to start all over again. You don't mention where you live or what climate, but I've heard that a winter's worth of road salt can cause this type of problem, or perhaps someone buffed the wheels in order to make them shiny but regrettably removed the clear coating on them. In order to help prevent a reoccurance of this in the future, I suggest a set of dust shields for the inside of your rims to help keep the brake dust off of your wheels.

Cheers - Jonathan

Looks like brake dust damage. More frequent cleaning will hopefully keep this to a minimum.