Ok here goes - rear wheel fitment on '13 GS
12-10-2019, 06:07 PM
#21
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2021 C6 of the Year Finalist - Modified
Gordonm ......
You never said the width of the 20" diameter wheels you have on the rear, so I assumed it is a 12" wide wheel, since you are using 345 / 25 -20" tires with it.
Going from a stock 325 / 30 -19" tire mounted on a stock 19" x 12" wheel with an offset of +59mm ... and installing a 345 / 25 -20" tire on a 20" x 12" wheel with an offset of +41mm, the calculator says this:
"Compared to the OEM 19” rear wheel, this new 20” rear wheel will have an inner rim which is 18mm further away from the suspension strut ...The outer rim will poke out 18mm more than the OEM wheels"
https://www.willtheyfit.com/index.ph...2-0&offset2=41
You never said the width of the 20" diameter wheels you have on the rear, so I assumed it is a 12" wide wheel, since you are using 345 / 25 -20" tires with it.
Going from a stock 325 / 30 -19" tire mounted on a stock 19" x 12" wheel with an offset of +59mm ... and installing a 345 / 25 -20" tire on a 20" x 12" wheel with an offset of +41mm, the calculator says this:
"Compared to the OEM 19” rear wheel, this new 20” rear wheel will have an inner rim which is 18mm further away from the suspension strut ...The outer rim will poke out 18mm more than the OEM wheels"
https://www.willtheyfit.com/index.ph...2-0&offset2=41
12-10-2019, 06:28 PM
#22
Race Director
Gordonm ......
You never said the width of the 20" diameter wheels you have on the rear, so I assumed it is a 12" wide wheel, since you are using 345 / 25 -20" tires with it.
Going from a stock 325 / 30 -19" tire mounted on a stock 19" x 12" wheel with an offset of +59mm ... and installing a 345 / 25 -20" tire on a 20" x 12" wheel with an offset of +41mm, the calculator says this:
"Compared to the OEM 19” rear wheel, this new 20” rear wheel will have an inner rim which is 18mm further away from the suspension strut ...The outer rim will poke out 18mm more than the OEM wheels"
https://www.willtheyfit.com/index.ph...2-0&offset2=41
You never said the width of the 20" diameter wheels you have on the rear, so I assumed it is a 12" wide wheel, since you are using 345 / 25 -20" tires with it.
Going from a stock 325 / 30 -19" tire mounted on a stock 19" x 12" wheel with an offset of +59mm ... and installing a 345 / 25 -20" tire on a 20" x 12" wheel with an offset of +41mm, the calculator says this:
"Compared to the OEM 19” rear wheel, this new 20” rear wheel will have an inner rim which is 18mm further away from the suspension strut ...The outer rim will poke out 18mm more than the OEM wheels"
https://www.willtheyfit.com/index.ph...2-0&offset2=41
12-11-2019, 12:10 AM
#24
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OEM Stock GS / Z06 Wheels and Tires:
__________________________
Front Wheel:
18 x 9.5
+40 mm Offset
Front Tire:
275/35 -18” (25.6” Diameter)
Rear Wheel:
19 × 12
+59 mm Offset
Rear Tire:
325/30 -19” (26.7” Diameter)
__________________________
Front Wheel:
18 x 9.5
+40 mm Offset
Front Tire:
275/35 -18” (25.6” Diameter)
Rear Wheel:
19 × 12
+59 mm Offset
Rear Tire:
325/30 -19” (26.7” Diameter)
12-17-2019, 03:47 PM
#25
Intermediate
It's interesting to me that Gardonm is having a rubbing issue when in another recent thread on spacers several place 20 mm spacers with no issues. I guess it is just the variation between cars and 18-20 mm of additional poke beyond stock is getting into the danger zone. Possibly ride height is playing a factor?
12-17-2019, 05:36 PM
#26
It's interesting to me that Gardonm is having a rubbing issue when in another recent thread on spacers several place 20 mm spacers with no issues. I guess it is just the variation between cars and 18-20 mm of additional poke beyond stock is getting into the danger zone. Possibly ride height is playing a factor?
Last edited by weezon; 12-17-2019 at 05:37 PM.
12-17-2019, 06:28 PM
#27
Race Director
I am 18mm poke on the rim and 10mm tire poke vs stock so I am at 28mm more than the stock size.
Last edited by Gordonm; 12-17-2019 at 06:30 PM.
12-17-2019, 09:12 PM
#28
Intermediate
Ok, that makes sense. I knew there was only an eighth inch (3mm) difference in diameter between the stock and your tire, so I did not think that would be an issue. It's the 18mm poke to the outside from the wheel plus half the difference in width between the stock and your tire. Thanks for the info, Steve
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