I have the stock 18" and 19" wheels and tires on my C7. I want to upgrade to the Z51 wheels.

Can I use the 19" tires which are currently on the car in the rear as the 19" tires for the front if I upgrade to the Z51 wheels.

The reason I ask is that the current 19" tire is a P285/35ZR19 and the one specificed for the Z51 wheel is a P245/35ZR19

Does anyone know the differnence in these two tire numbers and will using my current rear tire on the front if I switch wheels work?

Thanks for your help.

 

That's a good question that I do not have the answer for. the P285 is taller and the tire compounds is different between the standard and Z51 so you will have to match compounds if you keep those tires.

 

The number after the P is width of the tire (more info on http://en.wikipedia.org/wiki/Tire_code). Personally I probably wouldn't try it, that said, I'm not so great with cars, so I don't know how much of a problem 40mm width difference would make...though they'd probably look weird sticking out if nothing else

 

The 19" Michelin Pilot SS that are on the rear of your Stingray have a 26.9" diameter and are rated for a 9.5 to 11" rim width. The 19" stock Michelin Pilot SS Z51 front tires have a 25.8" diameter and are rated for a 8 to 9.5" rim. The Z51 19" front rim is 8.5" wide, so a little narrow for the Stingray rear tire. Talk to a tire expert, it may work, but it may also affect the handling of your car.

 

Rear tire won't fit an 8.5" rim
Z51 tires differ in construction & compound from base tires
Case closed

 

I know mostly nothing about the C7, but pretty sure the wheel offset is different on the front vs rear on the C6.

 

True but OP will use Z51 wheels.

 

Thanks everyone. Basically what I gather from the thread is that the 19" tires that are on the back can't be used for front tires with a Z51 rim.

 

Got a fancy car, I'd wouldn't want to destroy my handling trying to save a few bucks putting tires specifically designed for the back of a base car on the front. When you mount the tires on wider wheels, they will fit. But the sidewall now stands up straighter and the ride is affected with the different sidewall profile. Also the offsets are different. The fronts are 56mm the rears are 79mm.

If you want to compare wheel and tire sizes and the difference they make in circumference and diameter go here:

http://tire-size-conversion.com/tire-size-comparison/

We are putting HRE P40SC's 19/20 on our base car. To compensate for the bigger wheels, we are doing 35's on the front and 30's on the back. The delta to circumference and diameter is insignificant. The mph will be off one tenth of a mile per hour every 10 starting at 20 mph. At 60, the factory speedo will be registering slow by a 5 tenths. Again, not statistically relevant.

 

You are absolutely correct. The offset front and rear is different. The fronts are 56mm the rears are 79mm. Identical offsets for the base car and Z51.

 

Sidebar question --- actual tire width Z51 vs base any difference at all on the actual 285's?

 

Im interested in knowing what size tires the 30 and 35 are that your putting on?

Im putting on 265/35/19 and 305/30/20 I dont have them on yet.

 

Our base convertible is my wife's daily driver. At 78, she is old and fast. So safety is job one which required run flats. #2 is ride quality. No fuel dragster size on the rear.

If you are planning aftermarket wheels, be aware that many will not fit a base suspension car in 18/19 sizing. I.e. our first thought was HRE 550R's. But their 18/19 barrels don't fit the car. When we went up to HRE 19/20, we switched to P40SC. Going all in $$$.

We have HRE P40SC's 19x8.5 and 20x10. We mounted Michelin Pilot Super Sports 245/35ZR/19 ZP and 285/30ZR/20 ZP. This combination is virtual identical to the stock D and circumference. Still run flat road safety and a factory ride.

 

These will - $1050 shipped

 

There's no problem with 19" wheels front and rear. OEM front wheel setup would be 19 x 8.5 with 245/35-19. OEM rear wheel setup would be 19 x 10 with 285/35-19 .

In fact a Z51 track or autocross car might go to 19" wheels front and rear and that for the wider selection of Extreme-Performance and R-comp tires.

Oh, you were wanting 19 x 8.5 with 285/35-19 on the front and then 20 x 10 with 285/30-20 on the rear ? The problem is substandard tire support at the front. The 255/35-19 would reach the specs of the 19 x 8.5 wheel and also maintain some front/rear stagger. The 245/35-19 would be ideal spec on the 19 x 8.5 wheel.

You really should be looking for 9.5" wide front wheels and 11" wide rear wheels and then tire sizes of 265/305. And then any wheel offset between stock and 5mm more outward than stock will work with those tire sizes. That's 265/35-18 front / 305/30-19 rear or 265/30-19 front / 305/30-19 rear or 265/30-19 front / 305/25-20 rear. Want to cut down on the front/rear stagger ? Certainly go to the 275 front tire on the 9.5" wide front wheel.

Here are some wheels:

BBS RS-GT
18 x 9, 54mm, 21 pounds weight, front, $900 each
19 x 10.5, 75mm, 23.5 pounds weight, rear, $1320 each
Listed at TR under the C6
These wheels are spec width for the 255/40-18 front and 295/35-19 rear tire sizes

OZ Superleggera III
19 x 9.5, 59mm, and likely use a 5mm spacer, front, $859 each
19 x 11, 75mm, rear, $885 each
20x 11, 75mm, rear, $975 each
Listed at TR under the C6
And these wheels are spec width for the 265/30-19 front and 305/30-19 rear tire size pair and also the 265/35-19 front and 305/30-20 rear tire size pair. The 19"/19" tire size pair has a better selection of track and autocross tires
.

 

Also, Forgestars will work...see the website.

 

Yeah, here are the wheel sizes that I'm looking for:

18 x 9.5, 56mm to 51mm offset
19 x 9.5, 56mm to 51mm offset
19 x 11, 79mm to 74mm offset
20 x 11, 79mm to 74mm offset

And for example if the 18 x 9.5 is 53mm offset then I want the 19 x 11 to be 76mm.

I'm going easy on the outward wheel offset because the tires are going up two sizes
.