rmorin1249

18/19 combo should ride a bit softer but suspension is a much bigger factor.

Larry/car

I would think the lateral G capability would be slightly better with the bigger wheels (less tire sidewall flex). Acceleration should be about the same? Probably no real performance difference between the tire sizes. The larger balloon tires will ride better and the wheels are better protected traveling over poorly maintained roads.

Gearhead Jim

When the C7 first came out GM/Michelin did some bragging about how the Z51 tires had a different tread compound from the base tires, and IIRC there were also some differences in the carcass itself. The base tires were overall said to be more biased toward comfort and long life than the Z51 version.

We put the Super Sports on our C6 Z51, which are the same size as the base C7. I felt that they had no better grip than our previous two sets of PS2's, and maybe a little less. Now we have the Super Sports in C7 Z51 size on our 2017, they feel noticeably stickier and throw a lot more small stones.

Different tools for different jobs, I suppose.

JerryU

They are essentially the same diameter! They have different aspect ratio's that compensate.

i.e. 40/35 for the 18/19 (diameters 25.7" front; 26.7 rear.)

and 35/30 for the 19/20 (diameters 25.8" front; 26.5: rear)

Yep lower aspect ratios ride harder. Always wonder how the 26 diameter wheels I see the kids riding around with that have essentially rubber bands for tires, ride! But agree the suspension is key.

My GS has stiff springs, a very large diameter front sway bar and a large one added to the rear the base car does not have. Sure I have mag shocks but at the softest setting not as soft a ride as the base car. Shocks can't make up for those stiff springs and large sway bars. However they can make it ride stiffer. It fact set at track it rattles your teeth!

B Chas

I love this place, you guys have insights and make things easy to understand. So as I read it, the front 2017-18s and the 2018-19s end up with the same tire diameter, so.....the smaller wheels get taller tires. Same for the back wheels/tires. The taller tire gives a slightly softer ride and slightly lesser cornering. Did I understand correctly?

Think they did it for the sportier look of a lower profile tire?

I've been using super sports on my C-5 and CLK-550 for years. Great tires, good combination of stickiness, ride and road noise. Only problem is I don't get the mileage.

mmarum

I purchased a 2018 Grand Sport on 7-20-17. All four wheels and tires were ruined in WA. St. road work on a bridge deck paving project last Tuesday, 8-15-17. The run flats had no give to the horrible elevation differences in the road and the state kept the speed at 60mph!! which was insane for the conditions. I will be pursuing a claim with them & am hoping to find a source for non-run flats to replace front 285/30ZR 19 and rear 335/25ZR 20 tires.

mmarum

I purchase a 2018 Grand Sport on 7-20-17. Great Ride! Only problem is all four wheels and tires got ruined last Tuesday, 8-15 when driving through a WA. St. Bridge repaving site on I5. The speed limit was reduced to 60 mph which was crazy too fast! Even though I was going 50 and slowing it felt like I ran into a curb. No doubt the stiff sidewalls on the run-flat low profile tires did not help. Anybody know who makes non-run
flat tires for 285/30 19 & 335/25 20 tires? Michelin says they only make one for the front at this time.

JoesC5

Incorrect info. The Super Sport 18/19 tires used on the base Stingray(2014-2017) have a different compound than the Super Sport 19/20 tires used on the Z51.

The 18/19 tires used on the base Stingray(2014-2017) are not as sticky as the Z51 tires.

JoesC5

Because the OD of the tires are the same and the Z51 wheel is an inch larger in diameter, the Z51 tires have 1/2 inch less sidewall height, making them have less sidewall deflection, thus a little stiffer ride.

JoesC5

Since they both have the same OD, there is no acceleration advantage, except for the Z51 tire being a different compound, which has more grip. Also the Z51 does have lower gearing that gives it an acceleration advantage over the base Stingray.

The base tire has a slightly softer ride as it has a 1/2 inch more sidewall height, allowing the sidewall to flex easier to absorb bumps.

MikeyTX

This !

JoesC5

I've been known to drive my C6 Z06 pretty hard, yet I have ~38,000 miles on my Bridgestone RE050A run flats.

Tire design and the car's alignment has a lot to do with tire longevity.

JerryU

Thought I said that? Quoting:

"Yep lower aspect ratios ride harder. Always wonder how the 26 diameter wheels I see the kids riding around with that have essentially rubber bands for tires, ride!"

JerryU

Yep, you got it right.

However the larger rims also allow them to "stuff" in larger front brakes, like my Grand Sport. Also from a cornering response standpoint the lower sidewall responds somewhat quicker. The mix, 19/20 is for looks. Those wider lower profile rear tires on the Grand Sport/Z06 are a PIA to mount!

tony abbski

I have the 19" and 20" wheels on my '16 stingray, and replaced the stock tires with Michelin Pilot Sport A/S 3+ and much prefer them over stock. They aren't as sticky, but I don't track the car so they are fine for me - plus, better wet weather traction, I can run them in cooler temperatures, they are much quieter, and I expect much better mileage out of them ( 4000 miles on so far). (You may have to view pic with a tablet to zoom in and see the tire size)

Foosh

Interesting Jim. I don't recall seeing or hearing that and wasn't around when the C7 first came out, so I stand corrected. I took a Corvette vacation between 08-16.

Thanks.

Tony, I also have a set of AS3+ on a 2nd set of wheels and also agree they are extraordinarily good tires. I know they are not quite as grippy in summer, but they are extraordinarily more so w/ pavement temps below 70º. I run the AS3+ from Nov-April, and PSS, May-Oct.

JoesC5

The aspect ratio is just one part of the equation.

The base C7 StingRay's rear tires are 285/35R19. The tire's ID is 19" and the OD is 26.7 ". That means the sidewall height is 3.85".

My C6 Z06 has the same 19" ID and the same 26.7" OD and the same 3.85" sidewall height.

But my Z06 has an aspect ratio of 30, not 35 as does the C7 Stingray.

Even though my 30 aspect ratio is less, my sidewall height is the same(3.85") a the StingRay's 35 aspect ratio. That is because the aspect ratio is the percentage of the tires width, and my Z06's width is 325mm instead of the StringRay's 285mm width.

So, you can't make a blanket statement that the lower the aspect ratio is, the harder the tire ride is. I have the same ID, the same OD and the same sidewall height as the C7 StingRay, yet I have a lower aspect ratio. That's why I say that it's part of the equation.

I believe you are only considering +1, +2, +3, etc increases in wheel diameter reducing the aspect ratio for a given tire OD, but as I have pointed out, that is not always the case.

JerryU

^^^^
Good points!

Recall going +1 when it wasn't a word being used! Couldn't get quality tires for my modified '67 Corvair, my first new car. Got custom aluminum 14 inch wheels and Continental 714s and they were not called low profile at the time, but were. Fit fine and were great handling in the Corvair!

Gearhead Jim

Glad you're back!

It's interesting that after the initial hoopla about the differences in the Z51 tires, they've been rather quiet about it.
Perhaps the issues/complaints with cold temperatures have stirred the pot enough that GM and Michelin don't like to talk about Corvette tires very much.

MikeyTX

Sorry, trying to equate a C6 Z06 to a C7 Z06 just doesn't cut it.