bearphoto

If you are talking a night or two no problem cracking. But in temps usually below 40 degrees you will experience a loss of traction so drive accordingly.

RonC7

Here's the GM service bulletin. Draw your own conclusions.

Ron

http://www.corvetteactioncenter.com/...king-1296.html

owc6

That bulletin only references the Z06 tires cracking.

Not something new or alarming for the rest of the C7 crowd.

RonC7

From the service bulletin:

2014-2017 Corvette, Corvette Z06

The 2014−2017 Corvette is equipped with Michelin Pilot Super Sport ZP Runflat tires or Michelin Pilot Sport Cup 2 ZP tires. These tires are ultra high performance, track capable summer tires.

This tire has reduced capability below 5°C (40°F) and it is recommended that suitable winter tires be fitted below this temperature.

Avoid driving, moving, or test-driving Corvettes equipped with Michelin Pilot Super Sport ZP tires below -7°C (20°F) as operating at these temperatures can cause damage to the tires.

Refer to the latest version of Corporate Bulletin Number 04-03-10-013: Driving Characteristics of Rear Wheel Drive Vehicles and Available Winter Tires for further information on available replacement winter tires for cold climate operation.

Foosh

Well, the bulletin just says equipped w/ Michelin Pilot Super Sport ZP tires or Michelin Sport Cup tires. Obviously, the Z06 is not the only one so equipped.

It doesn't say anything about tire size, and doesn't mention the Grand Sport, which has the same size PSS as the Z06.

Looks to me to be just a poorly constructed bulletin.

Stangslayer

Really?
2014-2017 Corvette, Corvette Z06

JerryU

Yep, as it states traction is reduced below 40F (actually I find it's reduced below ~45/50F.) The tires do however warm up when driving and traction improves.

It does say for the "summer only" tires listed (as is warned for all summer only tires) driving and storing below 20F MAY cause cracking. Suggest the MAY is no doubt a attorney required statement! Many have driven their cars below and not reported the tread cracking shown. However traction is certainly poor and doubt, at those temps, the tires will come close to warming enough to regain reasonable traction.

Last year leaving a night meeting it was ~30F so as I do when it's below 40, I put my Z51 in Weather mode. After ~5 miles I tried switching modes and found the traction was still poor! When back to Weather mode and took turns carefully! Fortunately in Eastern SC I seldom have to drive the Vette in weather below about 40F!

patentcad

Just Googled up this thread, thinking of taking my C7 on an 80 mile round trip. Outside temp when I leave will be 36º F or so. Car is in a 45ºF+ garage (after reading this I'll to out there and put the space heater on for an hour to get it warmer). I have driven the car in temps as cold as 28ºF or so with no issues, but the car does lose significant traction @ temps below 45º-50ºF, the colder it gets the less grippy they will be. On the other hand I would guess that my C7 in 35ºF weather still stops shorter and holds corners better than my Prius with snow tires (on dry roads). So I will take it out today (it should be 40ºF or higher on return leg of this errand), I just take it easy when cornering and try not to drop any torque bombs on the rear axle : ).

JerryU

With the recent cold shape had to take my Grand Sport (same tires as standard Z06 and same Michelin type as on all C7’s, just different size) out when it was 24F. Purposely tested some of the performance issues addressed in this Thread from folks reading bulletins!

As I always do when below 40F put it in Weather Mode to have the nannies engage sooner. Car temp read 24 F, tires read cold on the display and tire pressure 28 psi (pressure is a better indicator of tire heating than the Hot, Cold, Frozen screen.) At the end of my street I merge into a 4 lane divided highway. Little traffic so pulled out with moderate acceleleration and all was fine. Stayed on the main roads and in ~5 miles came to a stop light and with no cars in front or back, applied the brakes aggressively. Car stopped fine and the antilock system did not engage. When I arrived at my destination tire pressure had raised to 31 psi and still read Cold.

After my appointment 2 hours later it had warmed to 35 F. In Eastern SC warms quickly when the sun is shinning and no clouds! Display still read Cold Tires. Turned left from a stop light to a 4 lane road with no traffic, so accelerated as I would when warm. Rear stepped out a bit but nannies quickly made it very stable. Again applied the brakes aggressively when coming to a red stop light with no traffic. Stopped as it would when warm. No antilock activation.

Relative to cracking, a year after I got my September 2013 Z51 is when the issue became very active on the forum. As I recall the one pic from Canada was repeated many times. That car was subjected to possibly -40F (C=F.). There have been a few other reports when it was close to zero F.

DON’T TAKE MY COMMENTS AS A RECOMENDATION OF WHAT YOU SHOULD DO!. Your Car, Do as You Feel Comfortable! If you live in an area where you have to drive often when below 40 F should probably buy Winter or all-season tires. I would, as I did the many years I lived “up North!”

PS: A poster recently quantified cracking with this info, accept only what you wish!

“The tires that were cracked were primarily (maybe 90%) in two circumstances. First a very small percentage of the several hundreds C7’s which sat at Toledo CSX railyard for a week when the night time temperatures were in the single digits, experience tire cracking. Best estimates were that about 30 C7’s had a tire or two which developed cracks. Second, and the picture of this probably got 10,000+ views on the internet, was a person who went out at night in Canada in his C7, drove home several miles, got his tires warm in that process, then parked his tires on several inches of snow. His car literally heat-melted into the snow, creating tires-encased-within-ice. What was the temperature that night in Canada? -20 degrees. All four of his tires had cracks and were replaced under warranty. And third, some very, very isolated other cases where digits were around 0 degrees.”

Richard Ames

Drove in the low 40's in FL last week and ended up in the Weather drive mode it was so much like driving on a wet surface. Remember the tires will be a few degrees warmer than the lowest air temperature unless it stays low for hours.

blackvette86

Never had any problems with any such thing as tire cracking when I started driving a car unless it was 20 years old and had a reason to be cracked. Tires cracking nowadays is most likely because they are now 90% PLASTIC in them and very little real rubber in them. Cheaper to manufacture or what I don't know. A guy told me this more than 20 years ago that worked at a major tire company. I never knew that until he told me. Nothing made today is better quality than it was years ago and I have been driving for 45 years.. It's all about the money.

Jaykoh-Z51

(Z51) I do the weather mode as well when its wicked cold out here in ATL. Even still...the back will slip out pretty easily until they've warmed up a little.

BIG Dave

I disagree with this. The OP asked about one night at 20*. I wouldn’t change my tires for just one night.

DALE#3

You just paid 60-125k for a car to STICK to the road.What fun is worrying if my car will slide out around the next corner.Gee,I Better slow down before i turn.
I didn't buy it to poke around...Look at me it's 30 degrees and i made back with all the fenders.
If you ain't switching tires..PARK IT

dial666

I bought my c7 3 weeks ago in ST Louis, its was 8 degrees when i left for my 250 mile drive home, never had a problem. it has been sitting since tho

Patman

I'm still a little confused as to why today's summer tires don't perform well in cold weather, but back in the late 80s and early 90s I drove a few cars through entire winters on summer tires with no problems at all. The first was a brand new 1988 Dodge Shadow Turbo. It came from the factory with Goodyear Eagle Gatorbacks on it and I drove that thing daily and never had any traction problems and no problems with tires cracking. After that, I had two different 87 Mustang GTs, and in both cases I ran the same Gatorback tires through the winter. I also went through one winter with the OEM Goodyear runflats on the rear of my 98 Corvette.

So why did the summer tires designed back in the 80 & 90s work better in extreme cold than summer tires of today?

JerryU

Because the tire construction and tread compound did not provide lateral force capability over 1 “g.” The Michelin’s are more like a race car tire. Typically race car tires need to be warm to hot to get maximum traction.

Your ‘98 Vette would not come close to achieving 1 to 1.1 “g” lateral acceleration!

PS: Just checked. Lateral acceleration for ‘98 Vette was 0.93 “g.”

JerryU

There are drawbacks to that superior traction when warm in addition to poor traction when cold.

GM callers it “Chatter or Hopping.” It is dramatically worse than my C6 Z51 with the same width tires as my C7 Z51 at the same colder temps.

This is worth reading to understand why: http://netwelding.com/Wheel_Chatter.pdf

Patman

That chatter is driving me a little crazy actually, I will definitely be replacing the OEM tires with all seasons when they wear out, and will stick with them for the life of the car.

BELVIN20

Doesn't it make you wonder that when the Vette is built in Bowling Green in the winter, it gets in the 20 degree & lower temps there. The cars sit outside until they are shipped, so it seems GM has no worries with tire cracking issues, and you know for sure they cars are shipped & delivered in temps below 20 degrees. Just thinking about what they re telling us. Yes for sure traction is diminished when tires are cold, but the cracking issue does not seem to affect GM when built & shipped.