So its getting time to buy new tires on the GTA, and I'm seriously considering a rim change as well. The car currently has 18x8" rims up front with 18x9.5" rims out back, 235/40/18" front tires and 275/40/18" rear. I'm running Hotchkis lowering springs and Koni Struts/Shocks.

I've been looking real hard at the 17x9" cast snowflake rims from Year One. I think I'd like to swap out what I have now for a set of those with 275/40/17 tires up front and 275/45/17 tires in the rear.

I see a few possible advantages.
1. Tires are slightly less expensive
2. I wouldn't need to run the 10mm slip on spacers in the rear anymore
3. They would be hubcentric and bolt pattern correct
4. I'd be running a significantly wider tire up front
5. I'd have more sidewall all the way around
6. Less weight?

The main disadvantage being, less tire options available in the 17" sizes. I love the way my rims look now also, but the ride is slightly on the harsh side. If I could mellow it out just a bit more, I think it would be perfect. It's also way too easy to lock up the fronts with those vette brakes. I feel like a wider tire up there would help a lot.

Thoughts?

Here's what it looks like now:





And here's another GTA with the 17x9" snowflakes:

 

Another option I'm thinking about is to get two more of the 18x9.5" wheels for the front, and then run a 275/35/18 up there, with a 285/40/18 or 295/35/18 in the rear. That should solve the small front tire problem, but isn't really going to help with the ride quality very much.

When I build my 8.8" rear, I can do axle tubes that are 1/2" longer on either side to get rid of the spacers back there. I could do the bolt pattern correction on the wheels at that point too. I wonder if there's enough meat to have them machined to take a 3rd Gen WS6 style centercap...

 

the snowflakes look killer!!!

 

Having a 275 tire in all 4 corners is going to help your handling and braking - no matter if it is a 275-40-17 or 275-35-18.

17" is a sweet spot when it comes to ride and handling - it will ride better than an 18" equivalent and it will probably be faster on the track (road race or autocross). 18" is really good for perfect roads that some parts of the country have.