2007 GT500 stock wheels have "worm-like" etching under the clearcoat

[shelbygirl]

Yes, the car has 104000 miles, but I would like to know how this "worm-like" etching happens and is it time to get some new wheels?

The manual says 18" x 9.5" and 5 hole @ 114.3mm with +45mm offset.
What I don't know, is the stock backspacing and should I care?

It is more difficult to find rims with +45mm... but find many with +40mm.

Does that 5mm really matter?

 

[Dino Dino Bambino]

That worm like etching is caused by delamination of the clear coat from the underlying aluminum. The easiest cheapest solution is to have the wheels refurbished to look like new again.

 

[Mustang Mark]

That is the start of clear coat failure. The +40 offset will push the wheels out closer to the 1/4 panel. Generally speaking a 10” wide wheel with +40 offset and a 305mm tire Will be pretty close to flush with the wheel lip if you decide to go with new wheels.

 

[06 T-RED S/C GT]

Yes, the car has 104000 miles, but I would like to know how this "worm-like" etching happens and is it time to get some new wheels?

The manual says 18" x 9.5" and 5 hole @ 114.3mm with +45mm offset.
What I don't know, is the stock backspacing and should I care?

It is more difficult to find rims with +45mm... but find many with +40mm.

Does that 5mm really matter?

View attachment 73226

The back spacing for the 2007-09 GT500 18x9.5" wheels are 7.125 inches. To my knowledge +45mm offset rims are pretty common. I also have a set of Steeda Spyder wheels in 20x9.5" which also have +45mm offset. Unfortunately, I have no idea what that worm-like etching is from

 

[MasterofDisaster]

Can you sand blast them and clear coat them? One of my wheels has some crap under the clear coat. Dremel is doing absolutely nothing to clean it up.

 

[ShelbySteve]

I’m curious if anyone has had theirs refinished. I have the same wheels and mine are doing the same thing. Wonder if I should buy new ones compared to having mine refinished.

 

[Dino Dino Bambino]

It would cost a lot less to have them refurbished.

 

[Iceman62]

If you're happy w/ the rims, then get them refurb'd...if not, time to safe for some $pendy replacements.

 

[Gabe]

That is the start of clear coat failure. The +40 offset will push the wheels out closer to the 1/4 panel. Generally speaking a 10” wide wheel with +40 offset and a 305mm tire Will be pretty close to flush with the wheel lip if you decide to go with new wheels.

A 305 tire on a 10"-wide wheel will have quite a bit of sidewall bulge, especially if a 30- or 35-series profile/sidewall (a 305/40/18 allows more height for the sidewall, so the bulge is not at pronounced).

Also, a 10"-wide wheel with a 40mm offset will cause tire/fender contact over bumps in the back if the car is lowered.
Unless the max tire width installed is a 285 or a narrow 295.
Been there, done that.

If going with a 10"-wide rear wheel on an S197, I'd recommend 45-48mm offset to have the wheel tuck inside the fender.
10.5" width, 48-53mm offset, 295-305 tire.
11" width, 55-62mm offset, 305-315 tire.