B Stead

There are various sources that suggest that 265 front and 305 rear tires will work on the C7 at near stock wheel offset.

I'm thinking that stock wheel offset is 56mm front and 79mm rear.

Then I see one aftermarket wheel set at 57mm front offset and 72mm rear offset.

But let's read the tire charts:

245/40-18, 25.7" diameter, 8.5" wheel width, base model, additional note: run-flat diameter is 25.7"
285/35-19, 26.9" diameter, 10" wheel width, base model, additional note: run-flat diameter is 26.7"

265/35-18, 25.3" diameter, 9.5" wheel width
305/30-19, 26.3" diameter, 11" wheel width

-----------------------------------------------

245/35-19, 25.8" diameter, 8.5" wheel width, Z51 model, additional note: run-flat diameter is 25.8"
285/30-20, 26.8" diameter, 10" wheel width, Z51 model, additional note: run-flat diameter is 26.5"

265/35-19, 26.3" diameter, 9.5" wheel width
305/30-20, 27.2" diameter, 11" wheel width

265/30-19, 25.3" diameter, 9.5" wheel width
305/25-20, 26.0" diameter, 11" wheel width

275/30-19, 25.6" diameter, 9.5" wheel width
305/30-19, 26.3" diameter, 11" wheel width, additional note: This size pair finds Extreme Performance tires and clears the Z51 brakes with wheel diameter

-----------------------------------------------

One note, I didn't see any of these 305 tire sizes in an all-season tire
.

Glen e

I run a 10.5 in the rear and easily could run a 305.....

Glen e

The same exact specs for tire as stock z51- NITTO INVO

Wheel:
TSW NURBURGRING 20x10.5 5/120.65 ET65 GUNMETAL W/MIRROR CUT FACE
Item Number: 2005NUR655121S70

Once we put it on, my tire guy said we could have gone 305- but VERY happy with 65 offset.....wheel is right at fender lip

adamsocb

I am thinking of this combo on 19x9 & 19x10.5 for the track. Diameters are within 1% of stock Z51.

http://www.tirerack.com/tires/tires....omCompare1=yes

B Stead

275/30-19 and 305/30-19 ?

That's interesting but the rear tire shortens more than the front tire. Of course, it might be a good setup.

Also, the 265/35-18 and 305/30-19 pair is available in that RE-11 tire
.

VThokies

Glen,

Your car looks great! What are your front specs? And where did purchase these?

Thanks.

Glen e

Bought locally but look for speed depot vendor here total cost of tires and wheels was about 2400....

adamsocb

I am comparing the RE-11 diameters to the OEM Z51 19/20 Michelins and the 275/30-19 and 305/30-19 RE-11 Bridgestones are very close. In-fact both the front and rear RE-11s are just 0.2" smaller than the 245/35-19 and 285/30-20 OEM Michelins.

http://www.tirerack.com/tires/tires....ar=Z51 Package

I would do 18/19, but I understand normal 18" wheels will not fit over the Z51 brakes.

B Stead

Oh, your specs are the run-flat Michelins.

One thing to note about the Bridgestone RE-11, there is now a new compound the RE-11A. Hopefully, all the sizes will switch over to the new compound if the old compound is being closed-out.

There's a new compound in the Yokohama AD08 and it's the AD08 R. It has the 265/35-18, the 275/30-19, and the 305/30-19 tire sizes. This tire is often sized shorter and wider and thus like an R-comp. The sidewall is extremely stiff and it is very much a track tire. I've used the AD08 compound and I have to say that either it is slow to warm-up (in autocross) or doesn't stay sharp for very long. However, on the street it feels great so I suspect that it is just slow to warm-up.


Need 19" wheels front and rear ?

Under the C6, TR has the Oz Superleggera III at 19 x 9.5 59mm and 19 x 11 75mm. (Wheel spacers at 3mm to 5mm would allow some fine tuning.) Then their C7 wheel offsets, using narrower wheels, are 51mm and 76mm
.

dencos

I want to buy a set of these TSW's in 18/19 for auto cross, do you think
a 305/265 set would clear the fender and not rub on these wheels?