The GS +40/+59 offsets would look bad on a C5 IMHO.........
You are correct, I wasn't clear on the +79mm offset issue
It would be to deep for my C5 any way as a +74mm is what I run to be near flush depending on tire manf & size. I would need to run a 5mm spacer.....
I understand offset VERY well as this is what I have played with to date:
My consolidated list of personal stock
Wheel size,type, & weight in lbs ea
OEM MAG 17 x 8.5, 17.5
OEM MAG 18 x 9.5, 19.5
OEM MAG 18 x 9.5 w/ new Yoko 295/35-18 AVS sport non-runflats, 50
OEM MAG 18 x 8.5 w/ new Yoko 275/35-18 AVS sport non-runflats, 46
PWO 5 spoke Y2K repos 17 x 8.5 +58mm, 20
PWO 5 spoke Y2K repos 18 x 9.5 +65mm, 23
HRE 18 x 9.5 545 w/ clear center +58mm, 22
HRE 18 x 12 545 w/ clear center +74mm, 27
PWO 17 x 8.5 +58mm w/ oem runflat 245/45/17 (8/32 tread), 50
PWO 17 X 8.5 +58mm w/ new MT ET Street 26 x 11.50 x 17 with TPS & lots of weights, 45
OEM MAG 17 x 8.5 w/ NITTO 555 275/40/17 (1/2 tread), 45
OEM MAG 18 x 9.5 w/ stock OEM 275/40/18 runflats, 53
OEM MAG 17 x 8.5 w/ stock OEM 245/45/17 runflats, 47
OEM MAG 17 x 8.5 w/ new MT ET Street Radial 275/40/17, 47
OEM MAG 18 x 9.5 w/ new Hoosier R3S05 275/35/18 road race radial 4.5 32nds tread with std valve stems 42
CCW drag pack rear 16 x 10 classic full polished with well worn MT ET Street 26 x 11.50 x 16 (1/32 tread) with center cap, 34
CCW drag pack rear 16 x 10 classic full polished with 1/2 worn MT ET Street 26 x 11.50 x 16 (3/32” tread) with center caps, 38
CCW drag pack front 16 x 5 classic full polished with like new Firestone deluxe champion 5.00/5.25-16 (10/32 tread) with center cap, 33
OEM runflat 275/40/18 worn to wear bars, 29
Bridegstone expedia S-01 345/35/18 (9/32 tread), 37
New MT ET Street Radial 275/40/17 (6/32 tread), 30
New MT ET Street Radial #3784R P315/30R18 26X12.50R18 (6/32 tread), 28
New MT ET Street 26 x 11.50 x 17 tires (6/32 tread), 25
MT ET Street 26 x 11.50 x 16 tires worn out (1/32” tread) 15.75
MT ET Street 26 x 11.50 x 16 tires (3/32” tread) 18
OEM runflat 245/45/17 (8/32 tread), 29
BFG G-force drag radial 345/30/18 new, 30
BFG G-force drag radial 345/30/18 1/32nd, 29.5
BFG KDW2 295/35/19 new, 32
Yoko 295/35-19 AVS sport non-runflats (2/32 tread), 29
Toyo Proxes RA1 335/30ZR18, new, (8/32 tread in the middle & 6/32 outside edges), 33.2
Topline 5 spoke Y2K chrome repos 18 x 10.5 +58mm offset rims w/ new MT ET Street Radial #3784R P315/30R18 26X12.50R18 , 58
Topline 5 spoke Y2K chrome repos 18 x 10.5 +58mm offset rims w/ new 275/35/18 BFG G-force TA drag radial, 53
Bob' House of Wheels 18 x 10.5 Chrome Y2K repos widened to 18 x 12. Work was done by Weldcraft Wheels.+56mm (with the 1.5" strip inserted, they should be right at 9.375" backspace, 31
HRE 18 x 12 545 w/ 345/30/18 BFG DRS, 57
HRE 18 x 9.5 545 w/ clear center +58mm w/ new 275/35/18 BFG KDWs, 52
HRE 18 X 9.5" 545 full polished w/ Yoko 265/35-18 AVS sport non-runflats (8/32 tread), 50
HRE 18 x 12 545 w/ 345/35/18 EXPEDIA S-O1 (9/32 tread), 64
HRE 19 X 10" 545 w/ Yoko 295/35-19 AVS sport non-runflats (5/32 tread), 58
HRE 19 X 10" 545 w/ new BFG KDW2 295/35-19 (10/32 tread), 61
HRE 18 x 12 545 w/new Toyo Proxes RA1 335/30ZR18 & TPS, 58.4 lbs
My best 60' times on my 97':
New MT ET Street Radial 275/40/17 on C5 OEM 17 x 8.5 Magnesium wheels = 1.47 60'
Worn out 26 x 11.50 x 16" Mt ET Street on a 16 x 10 CCW drag pack = 1.51 60'
New 26 x 11.50 x 17" Mt ET Street on an PWO Y2K 5 spoke 17 x 8.5 = 1.53 60'
1/2 worn (3/32” tread) 26 x 11.50 x 16" Mt ET Street on a 16 x 10 CCW drag pack = 1.53 60'
1/2 worn 345/30/18 bfg dr on HRE 545 18 x 12 wheel = 1.49 60'
HRE 18 x 12 545 w/ 345/35/18 EXPEDIA S-O1 (9/32 tread) street tires = 1.75 60'
I have over 450 passes on these set-ups together and at different tracks....
My best 60' times on my 00' vert:
Topline 5 spoke Y2K chrome repos 18 x 10.5 +58mm offset rims w/ new MT ET Street Radial #3784R P315/30R18 26X12.50R18 = 1.69 60'
Topline 5 spoke Y2K chrome repos 18 x 10.5 +58mm offset rims w/ new 275/35/18 BFG G-force TA drag radial = 1.69 60'
I have over 150 passes on these set-ups together and at different tracks....
Interesting fact.........I love my MAG wheels for this reason:
* The Exports have a different offset measurement at the mounting point so as to bring the wheel and tire in-board under the fenderwell approximately 1/2 inch. These wheels can be identified by a Black Line drawn around the circumference of the wheel between the beads. This Black Line will be seen only when the Tire is removed from the Wheel
Domestic / Export Magnesium 5-Spoke RPO N73 **
Front - 17" x 8.5" - #9592638
Rear - 18" x 9.5" - #9592640
** These wheels have always had the offset to meet Export requirements
C6 non Z06/GS
Front 18 x 8.5, +56 mm offset
Rear 19 x 10, +79 mm offset
C6 Z06 & GS (SPEEDLINE is the manufacturer for the GSs)
front: 18 inch x 9.5 inch, +40 offset
rear: 19 inch x 12 inch, +59 offset
FWIW, here are a few photos I've seen from posts on the forum of OEM Z06 wheels and tires mounted on a non Z06 C6. I may slap some GS wheels on one of my C5s for some pics just to see..........
Here's a pic just to give you an idea of the GS wheels on a C5 look..........there was a set for a good price and I was looking.......but they will not fit right and look poor on a C5 IMHO
PM me if ya need anything else Lut