GingerGranny

Looking to potentially go a little wider out back. What tire sizes have people put out back on their Grand Sports with the stock 19" wheels?
Currently have 325/30/19's on the rear.
Pictures would help as well if someone has gone to 335 or 345 on the 19" rears.
Also, did it throw off your speedo or any other issues?

FAUEE

I had 345s on my 2010. If you get the correct size fronts ro match, it's not an issue. That said, they're expensive, and didnt really add any extra grip compared to a 325, you get a better grip increase from tire compound than tire width.

Shaolin Crane

I have 345 30 20s on my GS. Fit is perfect. Rubs a little with a passenger but nothing terrible.

mcandrew67

I have 345/30-19 fine, no issues

rjken1969

I have been looking into this for a while anticipating my next tire purchase. Based on what I have found on this forum it's hit or miss whether or not there are issues with the traction control system utilizing the stock front tire size.. Going to a slightly larger tire size in the front will fix any issue, its the ratio between the front and rear tire, something around 1.1:1 is optimum. There is a lot of info in this subject on the forum.

The issue I have found is finding a matching set utilizing 285/18 on the front and 345/19 on the rear. It seems that these are not popular sizes Michelin and Nitto seem to be the only ones I can find, and they are not cheap. It adds an extra $500-$1000 to the set depending on the mfg. Post up if you find another option.

If you go to a 19/20 wheel size there seem to be more tire options. I personally don't like the look of a 20 wheel on the rear of a C6, I think the 19 with a fatter tire wall fills the wheel well much nicer.

jbc1995fb

I have 345's on the back. I've seen threads where people ran 355's. Tire Rack had a closeout sale one time on the 355's and people used them. Here's some links.

https://www.corvetteforum.com/forums...5-30-19-a.html

https://www.corvetteforum.com/forums...-zo6-rims.html

https://www.corvetteforum.com/forums...r-z-or-gs.html

jbc1995fb

Did you mean 345 on the rear? you said 245.

I'm running 345's on the back and stock size on the front. I'm even mixing run flats on the front and non-run flats on the rear. I haven't had any issues.

Spaceme1117

The rear tires on my 2011 Grand Sport are the stock size and everytime I look at them from the rear, I cannot get over how freaking wide they are. I don't think going any wider would make any difference in grip.

LeifAshley27

and here I am thinking I'm limited on tires with a 20" rear.

mcandrew67

forgot to mention I am 275/30-19 on the front so I am 19's all round.

rjken1969

Yes, 345 was what I meant.

Sox-Fan

I'm one of those. 285 pirellis on the front and 355 on the back. Got the backs for about $125 each. They rode nice, were pretty grippy, lasted a lot of miles, and looked great too. Boy oh boy would I love that deal again!!

Anyhow, 355's will fit.

Shaolin Crane

I got a similar deal for PSS in a 345/30/20 for $380 shipped a pair. Not quite as cheap but definitely cheap for a PSS

GingerGranny

In speaking of the optimum ratio mentioned above, are there issues when you throw a drag pack (smaller diameter wheel) on the back? Or do you turn traction control and all of those goodies off and say "to hell with it, I like to party!"?

CamarosRus

I have purchased Michelin Super Sport 345/30-19 & 295/30-19 from DiscountTireDirect.com (20% rebates during BlackFridayWeekend) (Free Shipping NO Sales Tax)
I have also ordered SIGNATURE SV501's in 19x12.5 et57 & 19x10.5 et37 Brushed Finish with CLEAR Powder Coat Finish
I also purchased these at Black Friday pricing (contact Khoa@SignatureWheels.com)

I will post pictures when I have received wheels, mounted, balanced and installed

Verrückt ZR1

In for pics.

jost6453

TorchRedFred

Me too, looking forward to pics. Wheels sound real nice. I like that you stayed with 19's in the rear instead of 20's. I definitely prefer the looks of the 19 rears on a C6.

Shaolin Crane

I prefer 20s personally. I ran a higher sidewall than what's popular and it completely filled out the wheel well without needing to lower the car at all. I like some meat on my sidewall and 19s just didn't fill out the rear well enough for me. This is 285 30 19 fronts and 345 30 20 rears.

TorchRedFred

Nice car! There are some exceptions to my 20" wheel rule. For the most part, I feel like 20" wheels with small sidewalls take away from the look of the C6 and constantly draw your eye to the wheels making it look like the 20's are out of place on a C6. There are a few examples that I would be willing to live with though.