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Discussion Starter #1
Little confused on the factory wheels on my 09 coupe.
I thought fronts were 18"x 9" and rears were 18" x 10"
However some sites show 18" x 9.5" on all four corners
I want to go with the Chrome FR500 wheels from American Muscle
and they come in 9" and 10"- Want to avoid any problems related to offset & backspacing.
By chance is anyone running these FR 500 wheels? If so did the alignment have to be re-worked?
I want to stay with 18" wheels as the roads in Michigan are horrible and going to 19" or 20" will only make the ride worse.
Any information is appreciated.
Mike
 

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I'm pretty sure Ford used a 9.5" width on all year models, just using different diameters. Generally alignment doesn't have to be redone, but there are no guarantees if the offset and tire sizes change. I don't know that it would change much, but why take a chance. These tires aren't cheap.

I see FR500 in various sizes, so Ihave no idea what you are looking at. If it were me, I'd go 10" front and back. Why would you want to go with a smaller width than stock? Offset would need to be 45mm, 24mm is too shallow. These are the offsets I'm seeing on FR500s. If you're looking at something, please provide a link. You would need to find out if the 10" wheel will clear the front calipers. I run 285/35-20s on the front of my lowered Shelby, so there's more room than you think.
 

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#1 Mike!
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MOFT500: Listen to Catmonkey. He is the forum's resident expert on wheel sizes, off sets, and anything round that fits around the brakes of a GT500! He will give you sound advise as he has done for many of our forum members.
 

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Discussion Starter #5
I understand and appreciate all help. I sent him the link on where I got the offset data. I fully agree that 24mm will not work but Catmonkey seems to see a 45mm offset for the FR500 and I'm not sure where that came from.
Factory wheel is 45mm so I need to maintain that dimension.
 

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You're going to have to run rather narrow tires with a 24mm offset. Looks like the ones I saw were 20s.
The part that spooks me is they label as rear only. Is there a fitment issues with the front calipers? I just think a 9" width limits front tire sizes. Maybe you like the big and little look, so that might work for you.
 

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Discussion Starter #8
Catmonkey,
Are the factory Brembo calipers 4 piston or 6? According to American Muscle wheel specialist the 10" will fit the front if I don't have 6 piston Brembo's. I just looked on Tire Rack and they offer nothing that fits a GT 500 in Chrome.
I think going 10" all around would be best if they fit.
 

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The 07-12 cars have 4 piston Brembos. !3-14 got the 6 piston. They can be installed on the later cars, but if your brakes are stock, they're 4 piston.

I just did a search on Summit using the following criteria.
  • chrome
  • 5 x 4.5" bolt pattern
  • 9.5", 10', 10.5" wheel width
  • 18", 19" and 20" diameters
  • 45", 48" and 52" offsets
You should be able to use this link to find the results.

Personally of the results I like the American Racing Torque Thrust M in 18x10.

Steeda has wheels with decent offsets too. You might check those out and see if they have anything you like.
 

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Moderator Dude!
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Good info above. I’ll add that one reason to go with a 9” vs. 10” wheel up front is it will reduce wheel weight a bit. You will still be able to run your original front tire size on a 9” wheel. I have 8.5” front/9.5” rear wheels on my 2011 GT500.
 
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