Biggest upgrade i could've made...

[Iroc2Vette]

Or, at least it feels that way....

After 17 months, the OEM GY EMTs finally needed replacement. I got a set of Michelin Super Sport (non EMT) tires installed. OMG!!! The difference is like night and day!!
1) No more hop and chatter from the front tires when doing a tight turn.
2) No more deafening howling
3) No more tramming (unless the roads are really badly rutted)
4) No more pancaking or crab walking on badly chopped up roads--I live in New England, and the plows really chop up the roads here. Not to mention all the frost heaves.
5) No more having the rear end roll over a cold paint line on the road doing a 90° and have the rear end just fly out to the side
6) No more nailing the gas at 3500 rpm and having the car want to do a pirouette to the left lane on the highway
7) Hello smooth and supple ride (It now rides smoother than my Mazda 3iT!!)
8) No more riding on chopped up pavement and having the steering wheel try to twist out of my hands
9) The car feels smaller and not as wide on the road
10) Most I was able to pull, G wise, from the GYs was a bit over 9g. Not bad, but, the Michelins did 1.14 around the same turn.

The only thing I can say about the GY EMT OEMs is they kept the rims off the pavement. If I had to rate them from a 0 (worst) to 10, I'd give the GYs a ZERO with a foot note *not worth the powder to blow them up with. They OEM GYs absolutely RUINED the Z06's handling.

With these tires, it feels like I upgraded everything. These tires feel like they were made for my car.

Originally, I almost decided against getting a Z06 after driving a 2012 with 1300 miles on it. I took it out on the highway and it trammed like crazy. I decided that the fundamental design of the car's suspension was sound. And that it must be the tires causing the uncomfortable instability. So I took that gamble. Thankfully, my past experiences with HiPo tires allowed me to make the right decision. It WAS THE TIRES!!

Note: I've also heard that Bridgestones and Nittos work very well, too. I choose the Michelins because that's what the new C7s are using, and the handling of these cars have been winning accolades, even in Europe, where they largely hate Corvettes. Amazing the difference a good set of tires make!

 

[Hib Halverson]

Do you feel that going from a worn out set of Goodyear run flats to a new set of Michelin non-run flats might skew your "results" a bit?
otfl

 

[Iroc2Vette]

First, a bit of background:

Interestingly, I almost decided against buying the Z06. I'd test driven a 2012 Z06 that only had 1300 miles on it. It was traded in because the original owner decided the 911 series Porsche drove better. This car had the exact same GY EMT tires with the asymmetrical tread....each tire was labeled for each corner of the car. When I drove the car on I-95 in the East Haven area, the car was tramming badly. And I had to really sleep on whether it was the tires or the car or both. I didn't like the feeling of it at all. And, the front tires also hopped and chattered when doing a tight turn. In fact, there is a slip of paper included with my owner manual stating the 'tram' and hopping on tight turns is normal. Hmmmmm.....

I decided the issue must be with the tires, as, imo, the suspension design of the car is fundamentally sound. Double wishbones front and multi link in the rear with CVs. The only difference are the composite springs, when compared to a conventional suspension. And, I've had a lot of experience with different kinds of tires in the past with my IROC. I took the gamble and ordered the Z, determining the tires were the culprits. And I can't begin to tell you how pleased I am that I was right.

I also have heard from other Z owners that even when they went to other brands, like Bridgestone and Nitto, the difference was day and night.

But, to more directly answer your question, the tires were just as bad new as they worn. Wear made zero difference.

All I can say now, is my Z rides almost like a Lexus or MB. It's as sedate and serene around town as one pleases, or can feel like a keg of dynamite going off behind one's back if one is in the right gear.

The other thing is I think my Z is even faster, as I'm not burning any rubber at all now. I did notice a difference in Road and Track between a Z with GY tires and one with the Z07 option, which has the Michelin SP2s, I believe. The 0-60 difference was, if memory serves me right, 3.7s /w the GYs and 3.4s /w the Michelins. That's a HELLUVA big difference, imo,

 

[Hib Halverson]

I appreciate your reply.

I have Michelins on my Z06 as well, but they are run-flats.

Let me ask you this, do you feel a comparison of a Goodyear run-flat to a Michelin non-run flat is a fair one?

What can you tell us about run-flat tire construction vs. non-run flat tire construction as to ride, handing, "tramming" and hoping.

And yes, with C6 Zs, the front tires "hopping" is normal. It occurs because the tire is so wide, in tight turns, the inside of the tread and the outside of the tread travel different enough distances that some of the tread actually has to "hop" along the road.

Z06es with Z07 had PS2s the first year and PS Cups the last two.

 

[Tuna]

My 427 Vert has the even wider ZR1 width tires and wheels and came with the Michelin PS2 run-flat tires. They follow the ruts and ridges in the road. Their aspect ratios are 30 front and 25 rear.

My CTS V has Pilot Super Sports, non run flats, in narrower sizes with aspect ratios of 40 and 35 and they follow the ruts and ridges some also but not nearly as bad as the 427 Vert.

My Volt is non run flat tires with 55 aspect ratios and it doesn't seem to know if the road has ruts or ridges.

I think the stiffer side wall of the run flat has a lot to do with that along with the aspect ratio.

Non run flats will always feel "better" due to the softer side walls. Given the my Vette goes on regular road trips and I prefer not to sit on the side of the road waiting for a tow truck, I'll keep the run flats on it.

 

[Iroc2Vette]

I appreciate your reply.

I have Michelins on my Z06 as well, but they are run-flats.

Let me ask you this, do you feel a comparison of a Goodyear run-flat to a Michelin non-run flat is a fair one?

What can you tell us about run-flat tire construction vs. non-run flat tire construction as to ride, handing, "tramming" and hoping.

And yes, with C6 Zs, the front tires "hopping" is normal. It occurs because the tire is so wide, in tight turns, the inside of the tread and the outside of the tread travel different enough distances that some of the tread actually has to "hop" along the road.

Z06es with Z07 had PS2s the first year and PS Cups the last two.

It may not be a really 'fair' comparison as the construction of both types of tires are different. I think a lot of the criticisms foisted by the European auto journalists on pre 2009 C6Zs are due to the GY EMTs.

I'm not all that knowledgeable about the construction of run flats vs non run flats except for the following:
The side walls are reinforced and stiffer on the EMT tires. There's a inner solid core to support the weight of the car in the event of a zero pressure situation. EMT tires generally require a technician with, I think, TPC? certification to properly work on them. They're more expensive to mount due to the extra labor involved.

I believe EMTs originally came from the aero space industry, and tires developed for Presidential limousines for the purposes of allowing escape in case the tires are shot out.

The front end of my C6Z stopped hopping with the Michelins. I even have a slip of paper that came with my car describing the issues of tramming and sharp turn hopping. So, with the GY EMTs, all that is normal, unfortunately.

I can't say if the Michelin EMTs are any better than the GYs as I can't make a direct comparison. The extra cost of the Michelin SP2 EMTs are over $2K vs about $1400 for the non EMT versions. That's a HUGE difference. The GYs are about $1660. In fact, I don't think the exact GY EMTs are available anymore and now GY sells a different EMT that does not require the tires to be assigned to a specific corner of the car.

You are lucky to have the Michelins on your car, due to the Z07 package. I could've ordered that RPO as well for mine. But, I couldn't justify the extra cost of some $9300 or so when I'll probably never track the car. So you've never had to experience the foibles of the GY asymmetric EMTs. If I would've know what I know now, and if GM would've offered just the Michelins as a separate option, I would've paid the extra $ to get them.

In conclusion, now every time I take the C6Z out, I now marvel at how nice the car rides and handles. It's MUCH more relaxed where I can guide the car down very rough roads with just holding the steering wheel lightly at the bottom of the rim. Where before, I have to use both hands to keep the car going straight and keep the steering wheel from literally twisting out of my hands.