Rims question
Thread Starter
Racer
Joined: Oct 2006
Posts: 267
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From: Hattiesburg MS
Rims question
Hey I'm putting a set of C5 rims on my 95 Vette...which they run 17's on front and 18's on back. My question is by putting 18's on the back will it throw my speedometer of?
Race Director
Joined: Oct 2005
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From: Rolla Missouri
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It depends.
If you were to keep the overall tire diameter the same as it was with the 17's, then your speedometer would not be off.
You can do this by going to a lower profile tire when you move up to an 18 inch wheel.
I believe your car came with 285/40 17
285/40 17 = 25.98 inches diameter
285/35 18 = 25.85 inches diameter
The difference is only 0.19 inches. That small of difference, and you won't even notice the speedometer being off.
If you were to keep the overall tire diameter the same as it was with the 17's, then your speedometer would not be off.
You can do this by going to a lower profile tire when you move up to an 18 inch wheel.
I believe your car came with 285/40 17
285/40 17 = 25.98 inches diameter
285/35 18 = 25.85 inches diameter
The difference is only 0.19 inches. That small of difference, and you won't even notice the speedometer being off.
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From: Exit 89 GSP,Lakewood,NJ The Land Of Mojo
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As long as the diameter or circumference of the tire is the same, you won't have to worry about it.
The rim size has nothingto do with it.
The rim size has nothingto do with it.
Burning Brakes
Joined: Sep 2005
Posts: 953
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From: Wesley Chapel FL
I switched from 17 9.5 all the way around to 17 9.5 in the front to 18 9.5 in the back and 80's Rules did the calculations for me and i would have to be going like 160mph to notice a one mile per hour difference on the speedo .......
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Thread Starter
Racer
Joined: Oct 2006
Posts: 267
Likes: 0
From: Hattiesburg MS
Thanks for the Info....but I have 2 sets of C5 rims,...I'm gonna run 17 on front and back...that way I can rotate the tires. I have a set of 4 18's for sale for 300.00 if intersted PM me.