Wheel offset
Le Mans Master
Joined: Jun 2009
Posts: 6,528
Likes: 752
From: South Dakota
Here is a post from another thread that pretty much sums it up. (although in that thread it was for a Z06)
Good luck.
Good luck.
Here are the specs for both C5 and C6 OEM wheels:
Backspace/offset dimensions are as follows:
C5 (coupe/vert):
Front 17x8.5", 58mm offset = 7.03" backspace
Rear 18x9.5" 65mm offset = 7.81" backspace
C5 Z06:
Front 17x9.5", 54mm offset = 7.38" backspace
Rear 18x10.5", 58mm offset = 8.03" backspace
C6 (coupe/vert):
Front 18x8.5", 56mm offset = 6.95" backspace
Rear 19x10", 79mm offset = 8.61" backspace
C6 Z06 and C6 GrandSport:
Front 18x9.5", 40mm offset = 6.82" backspace
Rear 19x12", 59mm offset = 8.82" backspace
C5 and C6 wheel circle:
5 on 4.75" (120.65MM)
Wheel width and offset together will determine whether any given wheel will fit on the C5.
Here is a link to an explanation of wheel offset:
http://www.discounttire.com/dtcs/infoWheelOffsets.dos
You can change the wheel width and offset to something other than stock but in doing so you want to avoid having the wheel protrude beyond the fender and you also don't the wheel to interfere with inner fender wells or suspension.
Here is a link to a wheel offset calculator that you can use to see what happens with a proposed wheel with respect to the current wheel. The calculator tells you how much the inner and outer wheel edges will move and in which direction if you use a specific new wheel.
http://www.1010tires.com/wheeloffsetcalculator.asp
To use it I would use the C5 Z06 wheel specs for the current wheel. That's because the C5Z06 wheels have the outer edge just about flush to the fender (the look most people want to achieve) and also has adequate inner fender and suspension clearance.
Backspace/offset dimensions are as follows:
C5 (coupe/vert):
Front 17x8.5", 58mm offset = 7.03" backspace
Rear 18x9.5" 65mm offset = 7.81" backspace
C5 Z06:
Front 17x9.5", 54mm offset = 7.38" backspace
Rear 18x10.5", 58mm offset = 8.03" backspace
C6 (coupe/vert):
Front 18x8.5", 56mm offset = 6.95" backspace
Rear 19x10", 79mm offset = 8.61" backspace
C6 Z06 and C6 GrandSport:
Front 18x9.5", 40mm offset = 6.82" backspace
Rear 19x12", 59mm offset = 8.82" backspace
C5 and C6 wheel circle:
5 on 4.75" (120.65MM)
Wheel width and offset together will determine whether any given wheel will fit on the C5.
Here is a link to an explanation of wheel offset:
http://www.discounttire.com/dtcs/infoWheelOffsets.dos
You can change the wheel width and offset to something other than stock but in doing so you want to avoid having the wheel protrude beyond the fender and you also don't the wheel to interfere with inner fender wells or suspension.
Here is a link to a wheel offset calculator that you can use to see what happens with a proposed wheel with respect to the current wheel. The calculator tells you how much the inner and outer wheel edges will move and in which direction if you use a specific new wheel.
http://www.1010tires.com/wheeloffsetcalculator.asp
To use it I would use the C5 Z06 wheel specs for the current wheel. That's because the C5Z06 wheels have the outer edge just about flush to the fender (the look most people want to achieve) and also has adequate inner fender and suspension clearance.
Last edited by QCVette; Mar 28, 2013 at 07:34 AM. Reason: Corrected quoted numbers per the posts below.
Race Director
Joined: Apr 2007
Posts: 11,150
Likes: 890
From: South Western Ontario
Don't believe everything you read. I get these numbers:
C5 (coupe/vert):
Front 17x8.5", 58mm offset = 7.03" backspace
Rear 18x9.5" 65mm offset = 7.81" backspace
C5 Z06:
Front 17x9.5", 54mm offset = 7.38" backspace
Rear 18x10.5", 58mm offset = 8.03" backspace
C6 (coupe/vert):
Front 18x8.5", 56mm offset = 6.95" backspace
Rear 19x10", 79mm offset = 8.61" backspace
C6 Z06 and C6 GrandSport:
Front 18x9.5", 40mm offset = 6.82" backspace
Rear 19x12", 59mm offset = 8.82" backspace
C5 (coupe/vert):
Front 17x8.5", 58mm offset = 7.03" backspace
Rear 18x9.5" 65mm offset = 7.81" backspace
C5 Z06:
Front 17x9.5", 54mm offset = 7.38" backspace
Rear 18x10.5", 58mm offset = 8.03" backspace
C6 (coupe/vert):
Front 18x8.5", 56mm offset = 6.95" backspace
Rear 19x10", 79mm offset = 8.61" backspace
C6 Z06 and C6 GrandSport:
Front 18x9.5", 40mm offset = 6.82" backspace
Rear 19x12", 59mm offset = 8.82" backspace
