SoAlVette

2000 vert, can I run 295/40/R18 on OEM Silver 5 spokes using a 1/2" spacer, will they fit?

grinder11

I've been running 315/30/18s, without spacers, on my 2000 Vert for 15 years now and have had no trouble. Your 40 series tire is taller, but I'm sure you'll be OK. The wheelwell only sees half the diameter of the tire, and if my math is correct, your 295/40 tire would be only .925 taller on half the diameter. If it's just the width you're concerned with, you should be just fine without spacers. If you have Active Handling, I'm not sure if the discrepancy in diameters from front to rear is enough to throw a code, or not. I've never run a tire that tall, at 27.29 diameter. If I had to guess, I'd say your OK, but I hate to guess.......

SoAlVette

When I bought my car it came with new 245/45/17 (25.7" high) on the front and 255/45/18 (27" high) rear. I did not realize I could go as wide as a 315 on the rear without rubbing. The 315/30/18 is 25.4" high and 12.4" wide.
That seems too wide for a 9.5" wheel. Also, I can't go with a shorter rear than front without giving me traction control issues, from what i've read. I was not planning on replacing the front tires right now, so I would have to go taller in the rear, that is why I was thinking 295/40/18, plus it should not be a problem on the 9.5" wheel. Would a 305 be too wide for a 9.5" wheel?, I could run the 305/35/18 (26.4" high). New wheels are on the wish list for the future but not in the budget right now.

grinder11, are you running stock wheels?

USAZR1

A 295 is probably a little too wide, for an 18x9,5 rear wheel. A 285/40/18 is right at 27" tall and that would work fine. No reason to use spacers as they just aren't needed.

grinder11

No, I am not running stock wheels in back. 315 wide tires are WAY to wide for a 9.5" wide wheel, especially a 30 aspect ratio. Years ago, I bought re-pop chromed thin spokes in a 10.5" width from Bob@House of Wheels. They're still on there. I have about 3/8"-1/2" clearance on each side between the sidewall and inner fenderwell. I don't know if 315s will work on every C5. Accumulated error on the wheel offset, and production variances on the C5 itself could result in rubbing slightly on 1 side, while having plenty of clearance on the other. On my car, 1 side is closer than the other, but neither side has ever rubbed. Hope this helps, and good luck......