What offset for aftermarket wheels?
Thread Starter
Safety Car
Joined: Apr 2008
Posts: 4,833
Likes: 1,850
From: NJ
2025 C8 of the Year Finalist - Modified
2023 C8 of the Year Finalist - Unmodified
2022 C7 of the Year Finalist - Modified
2021 C7 of the Year Finalist - Unmodified
What offset for aftermarket wheels?
We are suppose to have 57mm offset, correct? Does 56mm offset work also? (The wheels are (4) 18x9.5's). 
Drifting
Joined: Jul 1999
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From: Baton Rouge LA
Here are the offsets for the base and ZO6, provided by another member:
C5: STANDARD THIN SPOKE
Front 17x8.5 - 58mm
Rear 18x9.5 - 65mm
C5: Z06
Front 17x9.5 - 54mm
Rear 18x10.5 - 58mm
I can't imagine that a difference of a mm would matter, but definately, if one were changing wheel width, the offset should remain the same, meaning the center line was the same (a 1 inch wider tire would be 1/2 wider on the outside, and 1/2 on the inside).
C5: STANDARD THIN SPOKE
Front 17x8.5 - 58mm
Rear 18x9.5 - 65mm
C5: Z06
Front 17x9.5 - 54mm
Rear 18x10.5 - 58mm
I can't imagine that a difference of a mm would matter, but definately, if one were changing wheel width, the offset should remain the same, meaning the center line was the same (a 1 inch wider tire would be 1/2 wider on the outside, and 1/2 on the inside).
Thread Starter
Safety Car
Joined: Apr 2008
Posts: 4,833
Likes: 1,850
From: NJ
2025 C8 of the Year Finalist - Modified
2023 C8 of the Year Finalist - Unmodified
2022 C7 of the Year Finalist - Modified
2021 C7 of the Year Finalist - Unmodified
Here are the offsets for the base and ZO6, provided by another member:
C5: STANDARD THIN SPOKE
Front 17x8.5 - 58mm
Rear 18x9.5 - 65mm
C5: Z06
Front 17x9.5 - 54mm
Rear 18x10.5 - 58mm
I can't imagine that a difference of a mm would matter, but definately, if one were changing wheel width, the offset should remain the same, meaning the center line was the same (a 1 inch wider tire would be 1/2 wider on the outside, and 1/2 on the inside).
C5: STANDARD THIN SPOKE
Front 17x8.5 - 58mm
Rear 18x9.5 - 65mm
C5: Z06
Front 17x9.5 - 54mm
Rear 18x10.5 - 58mm
I can't imagine that a difference of a mm would matter, but definately, if one were changing wheel width, the offset should remain the same, meaning the center line was the same (a 1 inch wider tire would be 1/2 wider on the outside, and 1/2 on the inside).
Thread Starter
Safety Car
Joined: Apr 2008
Posts: 4,833
Likes: 1,850
From: NJ
2025 C8 of the Year Finalist - Modified
2023 C8 of the Year Finalist - Unmodified
2022 C7 of the Year Finalist - Modified
2021 C7 of the Year Finalist - Unmodified
No, these are the ones I just sent back. But if you have any suggestions, I'm all 
