CT5-V 5BW new tire time - discussion

[TruckeeTaurus]

Please don't take this as me being a jerk, but Invos weren't true grippy high performance tires when they came out, what, 15+ years ago? And the 555 G2s are not particularly well respected as anything but an inexpenisve tire. The drag style 555Rs and such are supposed to be incredible in hooking up in a straight line but they have soft sidewalls (i.e. no good for handling).

I am largely content with the OE TPC-spec tires but I know the PS4S is getting long in the tooth and there are newer tires out there that might be pretty incredible, too. As I mentioned, the Potenza Sport is something I have tried in the past and was super impressed with the lateral grip, precise steering, and stiff sidewall (almost like the super 200TW style tires). But I have a feeling they wouldn't last long on a 5BW. The Yokohama AD09 is really the tire I wished they made in our sizes.

Why would I see you relating your personal experience as you being a jerk my brother? Yer good.

Maybe they’ve changed something up as almost all of the reviews I read about the Invo said they were great… though I doubt many of those folks are ripping 659 torque.

What really sucks is that there are not many all season or winter specific tires with specs for the rear tires. I’ve read the Alpin 4 is good, but can’t find them ANYWHERE. So I gotta take what I can get if I want to drive the BW in early spring or fall.

If you know of some good A/S or winter tires and where to get em, hook a brother up!

 

[Champale]

There is a big thread about that very problem somewhere on this forum if I recall.

If I needed an AS tire, I would look at the Michelin AS4 and run the factory size 275/35/19 up front and a 285/35/19 in the back. Slightly taller but slightly narrower tread in theory. However, when that 285 is mounted on the BWs 11" rear wheel, I bet it will look almost as wide as the OE 305s because, in my experience, the wheel width is about 90% of how the tire looks because the sidewall has to be attached right at the wheel lip anyway. On another car I have mounted 2 different PS4S tires that were supposed to be 1.4" different in terms of tread width but when actually mounted on the same 10.5" wheels, the naked eye could not tell any difference when I laid the wheels on the ground next to each other. They were the exact same width when mounted on the wheels.

Sorry, that's a long winded way of saying an AS4 in 285/35/19 would be my choice on the back.

 

[TruckeeTaurus]

There is a big thread about that very problem somewhere on this forum if I recall.

If I needed an AS tire, I would look at the Michelin AS4 and run the factory size 275/35/19 up front and a 285/35/19 in the back. Slightly taller but slightly narrower tread in theory. However, when that 285 is mounted on the BWs 11" rear wheel, I bet it will look almost as wide as the OE 305s because, in my experience, the wheel width is about 90% of how the tire looks because the sidewall has to be attached right at the wheel lip anyway. On another car I have mounted 2 different PS4S tires that were supposed to be 1.4" different in terms of tread width but when actually mounted on the same 10.5" wheels, the naked eye could not tell any difference when I laid the wheels on the ground next to each other. They were the exact same width when mounted on the wheels.

Sorry, that's a long winded way of saying an AS4 in 285/35/19 would be my choice on the back.

Changing up the tire specs doesn’t throw shit off on the car’s computers? I don’t want to mess with anything that could give Caddy a reason to void the warranty.

 

[Champale]

I am personally unaware of any such issues but I haven't researched it. It wouldn't be a bad idea to speak to your service advisor and see what tires they recommend for their 668hp, 205mph supersaloon. If you buy what they tell you, it would be hard for them to argue with warranty issues.

 

[Champale]

Come to think about, there are plenty of guys running non-standard tire sizes like 325s that are taller and I haven't heard of any ABS or stability control freakouts. But do your due diligence.

 

[TruckeeTaurus]

I am personally unaware of any such issues but I haven't researched it. It wouldn't be a bad idea to speak to your service advisor and see what tires they recommend for their 668hp, 205mph supersaloon. If you buy what they tell you, it would be hard for them to argue with warranty issues.

Good call. Bro, my dealership’s salesmen honestly aren’t well versed in the Blackwing. I knew more about it than them. I mean it’s not like I’ve been obsessed with the BW since 2021, checked every day for the last year to see if a car with my specific options was available, and read/watched anything I could find about the car…

 

[TruckeeTaurus]

Case in point: it was 38F driving over the Donner Summit just now. Gotta have tires that are safe at these temperatures.

 

[Champale]

I have driven on the OE tires in the 30s and wet and didn't die . . . but you do have to be a little careful.

 

[Finally-a-V]

Were those the Invos by chance? Figure I’ll only be able to run Summer tires for a few months out of the year which is why I wanted a tire that’s safe under 40F. September through April (some years through May too) I’ll need tires safe at cold temps.

Honestly, it's been so long I don't remember. They were 4 season performance tires.

 

[TruckeeTaurus]

I have driven on the OE tires in the 30s and wet and didn't die . . . but you do have to be a little careful.

I’ve heard both sides. Some have had their tires crack or blow the sidewall… others have had zero issues, so I just figured it’s better to be safe than sorry. I’ll change my wheels twice a year. Only positive thing of the car not coming with the wheel package I wanted.

 

[Brad_TX2V]

Extreme performance summer tires typically don’t fare well in freezing temperatures, they get brittle and can crack. I’ve seen it firsthand with racing slicks that came from the Chicago warehouse versus Georgia when I started out the race season in Florida in January - without even being on the car my Pirellis had MASSIVE cracks in them!! The tire guys made it right but it was an eye opener. Some tires fare well versus others but it’s something to be mindful of. I turn the heat on in the garage Mahal here in Texas to keep bad things from happening to my street tires in our winters (for the typically short Texas teen weather which we occasionally get!).

 

[TruckeeTaurus]

Damn bruh… what kind of heat are you talking about in the garage. I’ve never had to do that or even consider it because I’ve never driven on high performance tires in any of my vehicles.

I’ve got a propane heater kind like the ones used in outdoor seating for restaurants. I can’t imagine having to run that thing often though.

I figure in the winter it’ll be living in my Vallejo garage, and be brought out to play around the Bay Area. But spring summer and early fall I want to be cruising those winding mountain roads.

 

[Brad_TX2V]

Insulated garage with an AC window unit with heat. I’ll just set it to keep it 45 and above if needed. If I’m out there working I’ll keep it above 60. I’ve got a few small space heaters if needed. Not a fan of using those unless I’m in the garage though. I’ve got a remote temp gage that displays on the bedroom clock so I can monitor temps. The AC is NICE when it’s 100 plus outside! I used to think that tire cracking was a myth until I saw my own tires crack! These were going to be used at Homestead Miami on the Roval layout. That would’ve been catastrophic at 165 on the front straight! The side load on the progressive banking on NASCAR 4 is quite heavy!

Pic of window unit (top middle) with obligatory race car shot. And race tires. Since tires is what this is about! I’ve used the Pirelli wets in 32/33 degrees freezing rain at COTA with excellent results. Fortunately, no cracking. And that’s an even softer compound than a slick!! You have to run them in the wet or else they just melt/chunk off. That’s why you’ll see many racers going wet spot to wet spot on a drying race track.

 

[TruckeeTaurus]

Insulated garage with an AC window unit with heat. I’ll just set it to keep it 45 and above if needed. If I’m out there working I’ll keep it above 60. I’ve got a few small space heaters if needed. Not a fan of using those unless I’m in the garage though. I’ve got a remote temp gage that displays on the bedroom clock so I can monitor temps. The AC is NICE when it’s 100 plus outside! I used to think that tire cracking was a myth until I saw my own tires crack! These were going to be used at Homestead Miami on the Roval layout. That would’ve been catastrophic at 165 on the front straight! The side load on the progressive banking on NASCAR 4 is quite heavy!

Pic of window unit (top middle) with obligatory race car shot. And race tires. Since tires is what this is about! I’ve used the Pirelli wets in 32/33 degrees freezing rain at COTA with excellent results. Fortunately, no cracking. And that’s an even softer compound than a slick!! You have to run them in the wet or else they just melt/chunk off. That’s why you’ll see many racers going wet spot to wet spot on a drying race track.

View attachment 30047

Wow man! Thanks for sharing. That garage looks like a bedroom with cars in it… I mean I’ve seen apartments less nice than that!

I can appreciate any advice from someone so obviously experienced. It makes me more confident in my decision to get another set of wheels and tires.

Good looking out.

 

[jwolf99]

There is a big thread about that very problem somewhere on this forum if I recall.

If I needed an AS tire, I would look at the Michelin AS4 and run the factory size 275/35/19 up front and a 285/35/19 in the back. Slightly taller but slightly narrower tread in theory. However, when that 285 is mounted on the BWs 11" rear wheel, I bet it will look almost as wide as the OE 305s because, in my experience, the wheel width is about 90% of how the tire looks because the sidewall has to be attached right at the wheel lip anyway. On another car I have mounted 2 different PS4S tires that were supposed to be 1.4" different in terms of tread width but when actually mounted on the same 10.5" wheels, the naked eye could not tell any difference when I laid the wheels on the ground next to each other. They were the exact same width when mounted on the wheels.

Sorry, that's a long winded way of saying an AS4 in 285/35/19 would be my choice on the back.

So I picked up a matching set of the black satin wheels which I mounted AS4s onto for the winter. Here are the front and rears of the AS4s up against the PS4s. As other have mentioned the AS4 are 275/35/19 up front and a 285/35/19 in the back. The widths of the fronts are comparative, obviously since there's the same size. The AS4 rear is just a bit less wide than the PS4 at at the sidewall, but you can clearly see the narrower contact patch. I also threw in a photo to show the spread where the AS4 rear meets the wheel so you can get a sense of just how much it pulls away from the 11" wheel pulls.

Though the contact patch is smaller, they handle perfectly fine on the twisties even when pushing the car for extended periods of time. Granted, we're not talking track driving but they are more quite adequate for my winter driving. Also potholes are not a problem with the stretch on the 285s. I am in NY and have hit a few deep potholes in the mid of winter with the AS4s and no damage to the wheels at all.

 

[Brad_TX2V]

Got this email from Motor1.com today, an interesting read....

The Mind-Blowing Tech of the Corvette’s Michelin All-Season Tires

As an enthusiast, you might think that all-season tires aren’t worth a lick. Michelin proves otherwise.

— Chris Perkins, Senior Editor

Enthusiasts often think in simple binaries. Manual transmission good, automatic transmission bad; hydraulic power steering good, electric power steering bad. All-season tires fall into the same boat, compared with their more specialized summer or winter brethren. But reality isn’t quite so simple. Not all all-season tires are bad, just as not all manual transmissions or hydraulic power steering systems are good. There’s certainly merit in having the right tool for the job, but flattening the discussion around an entire category also means some really interesting engineering can get overlooked, like the C8 Corvette’s standard Michelin Pilot Sport All Season 4 tires. These are the first all-seasons fitted to a Corvette from the factory.

“I think there was a lot of discussion and maybe tension within Corvette whether or not they were going to do this,” recalls Steve Calder, ultra-high performance product category manager for Michelin. “Our feedback to them was [based on] listening to their customers for years. A lot of these people would like to drive the car on nice, cold mornings, particularly people living in Canada and the Northern US, but were uncomfortable driving on summer tires in those conditions, and willing to give up a tiny bit of the ultimate performance to get an all-season tire.” The definition of what constitutes an “all-season” tire is nebulous. Calder says that for Michelin, the goal is to provide “mobility in cold, and light, snowy conditions.” In order to do this, there is a quantifiable threshold the tire must meet.

It’s based on results from a standardized test, ATSM F1805, which measures traction of a single driving rear wheel on snow and ice. In order to be deemed an “all-season,” the tire must perform at 50% of the level of the test’s standardized reference tire. For context, a tire like a Pilot Sport 4S summer tire might only manage 10 or 20% on the test, whereas a tire that has the three-peak mountain designation indicating severe snow rating must perform at least 110% of the reference. The Pilot Sport All-Season 4 in its OE replacement spec scores between 65% and 75%, but Michelin company declined to provide the figure for the Corvette-spec tire. The Pilot Sport All Season 4 is not severe-snow rated, so don’t take your C8 Corvette out in a blizzard without true winter tires, unless you’re looking for trouble. But if you get a couple inches of snow, you should be all right.

"I think there was a lot of discussion and maybe tension within Corvette whether or not they were going to do this."

At the project’s outset, Michelin and Corvette came up with another goal for this tire—1g of lateral acceleration on the skidpad. A nice round number that would put these tires on par with dedicated summer performance tires from a generation or two back. And a number that would show the rest of the world that this was a serious effort, not just a half-hearted capitulation to customer demand. Achieving all these disparate aims, says Calder, comes down equally to two factors—compound and tread pattern.

It’s easy to think that tread pattern is the big differentiator between tire types because, well, that’s the thing we can see. If you put this tire side-by-side with the Corvette’s Pilot Sport 4S and a racing slick, you can immediately establish a hierarchy. All the extra cuts and grooves in the Pilot Sport All Season 4 help boost wet weather performance, and enable some snow-ability. But all that hurts overall tire stiffness, which is why you’ll see far fewer tread blocks on the Pilot Sport 4S, and none whatsoever on a slick, which is optimized for ultimate speed. So that’s where the compound comes in. “I used to be a test driver before moving to marketing, and I experienced a snow test with a slick,” Calder recalls. “I thought ‘there’s no way I’m going to get out of the garage,’ and actually, it was mobile. It was all about the compound they had put on there. It really opened my eyes to the effect that compound has on traction, even in snow.”

Compounds are so important, Calder’s not sure what would win in a hypothetical test—a slick with a great snow compound, or a winter tire with a summer compound. Of course, neither would be ideal, but you get the point. This is also where Michelin can make a big difference for the Corvette’s tires. Like a lot of its tires, the Pilot Sport All Season 4 is a tire Michelin sells in many iterations, and typically, all those iterations will have the same basic tread pattern. When developing a tire for factory fit on a specific car, you keep the tread pattern, but change up the compound and the construction. Michelin has a proprietary design and production process called C3M, which “allows the designer to put different rubber compounds just about anywhere they want in the tire,” Calder explains. “So whether they want to do a different compound or multiple compounds across the face of the tire if they want to do different compounds as the tire wears down or some combination of both.” As an example the longitudinal grooves that mostly deal with evacuating water are lined with a winter-tire compound. Traditional winter tires generate snow grip by packing snow into lateral sipes in the treadblocks. The effect is like that of a snowball—snow grips snow. In the Corvette’s all-season, the longitudinal grooves fill up with snow and create that same snow-on-snow contact, generating grip.

[td] Of course, the performance isn’t just down to Michelin either. A program like this represents a collaboration between the automaker and the tire supplier. Both the car and tire are optimized for each other. It’s a virtuous development cycle, each making the other better until the final product is realized. So, a lot of the work was down to Chevrolet optimizing the Corvette to work with what Michelin provided. I got a chance to drive a Corvette Stingray with these tires a few weeks ago. Unfortunately, it didn’t snow, so I wasn’t able to test that out, though a video from the excellent Tyre Reviews YouTube channel demonstrates that these tires have the sort of snow performance you’d expect: Good, but nothing compared to a dedicated winter tire. But, I was able to drive the car in a scenario Calder described exactly—a cold, dry day. The temperature barely exceeded 30 degrees, but the Corvette drove wonderfully. It was right down the middle between a dedicated winter and a dedicated summer tire. You got rubber that didn’t feel all hard and horrible, like a summer tire does in cold temperature, but basically none of the soft, floaty dry handling and slow response you get from a winter tire. Of course, it’s not as sharp as a car on dedicated summer tires in warm weather, but you can’t expect it to be. If I owned a Corvette, I think I’d still have a dedicated set of summers for warm weather, just for the sake of giving the car that more dialed, on-the-nose feel, but I might run these all-seasons instead of dedicated winters in the cold. For most customers, a Corvette is not a car they’re going to drive in heavy snow conditions in the winter—at most, they’ll take it out when it’s dry, and for that, the all-season works phenomenally. Calder says he’s seeing more automakers embrace these sorts of performance all-seasons following the Corvette’s lead. Not necessarily on sports cars, but things like sports sedans and high-po SUVs. These are cars where you get a lot of customers who run one tire year round, and moreseo than a Corvette, these are daily drivers, too. I think what’s possibly more interesting is what comes next. A tire program like this usually starts three or four years before vehicle production begins. When you consider the C8 Corvette went into production in 2019, this tire is, in a way, decade-old technology. So what’s the spread of performance look like in the next ultra-high-performance all-season tire? If this isn’t the tire to convince naysayers, maybe the next one will.​

​

[/td]

 

[TruckeeTaurus]

Got this email from Motor1.com today, an interesting read....

The Mind-Blowing Tech of the Corvette’s Michelin All-Season Tires

As an enthusiast, you might think that all-season tires aren’t worth a lick. Michelin proves otherwise.

— Chris Perkins, Senior Editor

Enthusiasts often think in simple binaries. Manual transmission good, automatic transmission bad; hydraulic power steering good, electric power steering bad. All-season tires fall into the same boat, compared with their more specialized summer or winter brethren. But reality isn’t quite so simple. Not all all-season tires are bad, just as not all manual transmissions or hydraulic power steering systems are good. There’s certainly merit in having the right tool for the job, but flattening the discussion around an entire category also means some really interesting engineering can get overlooked, like the C8 Corvette’s standard Michelin Pilot Sport All Season 4 tires. These are the first all-seasons fitted to a Corvette from the factory.

“I think there was a lot of discussion and maybe tension within Corvette whether or not they were going to do this,” recalls Steve Calder, ultra-high performance product category manager for Michelin. “Our feedback to them was [based on] listening to their customers for years. A lot of these people would like to drive the car on nice, cold mornings, particularly people living in Canada and the Northern US, but were uncomfortable driving on summer tires in those conditions, and willing to give up a tiny bit of the ultimate performance to get an all-season tire.” The definition of what constitutes an “all-season” tire is nebulous. Calder says that for Michelin, the goal is to provide “mobility in cold, and light, snowy conditions.” In order to do this, there is a quantifiable threshold the tire must meet.

It’s based on results from a standardized test, ATSM F1805, which measures traction of a single driving rear wheel on snow and ice. In order to be deemed an “all-season,” the tire must perform at 50% of the level of the test’s standardized reference tire. For context, a tire like a Pilot Sport 4S summer tire might only manage 10 or 20% on the test, whereas a tire that has the three-peak mountain designation indicating severe snow rating must perform at least 110% of the reference. The Pilot Sport All-Season 4 in its OE replacement spec scores between 65% and 75%, but Michelin company declined to provide the figure for the Corvette-spec tire. The Pilot Sport All Season 4 is not severe-snow rated, so don’t take your C8 Corvette out in a blizzard without true winter tires, unless you’re looking for trouble. But if you get a couple inches of snow, you should be all right.

"I think there was a lot of discussion and maybe tension within Corvette whether or not they were going to do this."

At the project’s outset, Michelin and Corvette came up with another goal for this tire—1g of lateral acceleration on the skidpad. A nice round number that would put these tires on par with dedicated summer performance tires from a generation or two back. And a number that would show the rest of the world that this was a serious effort, not just a half-hearted capitulation to customer demand. Achieving all these disparate aims, says Calder, comes down equally to two factors—compound and tread pattern.

It’s easy to think that tread pattern is the big differentiator between tire types because, well, that’s the thing we can see. If you put this tire side-by-side with the Corvette’s Pilot Sport 4S and a racing slick, you can immediately establish a hierarchy. All the extra cuts and grooves in the Pilot Sport All Season 4 help boost wet weather performance, and enable some snow-ability. But all that hurts overall tire stiffness, which is why you’ll see far fewer tread blocks on the Pilot Sport 4S, and none whatsoever on a slick, which is optimized for ultimate speed. So that’s where the compound comes in. “I used to be a test driver before moving to marketing, and I experienced a snow test with a slick,” Calder recalls. “I thought ‘there’s no way I’m going to get out of the garage,’ and actually, it was mobile. It was all about the compound they had put on there. It really opened my eyes to the effect that compound has on traction, even in snow.”

Compounds are so important, Calder’s not sure what would win in a hypothetical test—a slick with a great snow compound, or a winter tire with a summer compound. Of course, neither would be ideal, but you get the point. This is also where Michelin can make a big difference for the Corvette’s tires. Like a lot of its tires, the Pilot Sport All Season 4 is a tire Michelin sells in many iterations, and typically, all those iterations will have the same basic tread pattern. When developing a tire for factory fit on a specific car, you keep the tread pattern, but change up the compound and the construction. Michelin has a proprietary design and production process called C3M, which “allows the designer to put different rubber compounds just about anywhere they want in the tire,” Calder explains. “So whether they want to do a different compound or multiple compounds across the face of the tire if they want to do different compounds as the tire wears down or some combination of both.” As an example the longitudinal grooves that mostly deal with evacuating water are lined with a winter-tire compound. Traditional winter tires generate snow grip by packing snow into lateral sipes in the treadblocks. The effect is like that of a snowball—snow grips snow. In the Corvette’s all-season, the longitudinal grooves fill up with snow and create that same snow-on-snow contact, generating grip.

[td] Of course, the performance isn’t just down to Michelin either. A program like this represents a collaboration between the automaker and the tire supplier. Both the car and tire are optimized for each other. It’s a virtuous development cycle, each making the other better until the final product is realized. So, a lot of the work was down to Chevrolet optimizing the Corvette to work with what Michelin provided. I got a chance to drive a Corvette Stingray with these tires a few weeks ago. Unfortunately, it didn’t snow, so I wasn’t able to test that out, though a video from the excellent Tyre Reviews YouTube channel demonstrates that these tires have the sort of snow performance you’d expect: Good, but nothing compared to a dedicated winter tire. But, I was able to drive the car in a scenario Calder described exactly—a cold, dry day. The temperature barely exceeded 30 degrees, but the Corvette drove wonderfully. It was right down the middle between a dedicated winter and a dedicated summer tire. You got rubber that didn’t feel all hard and horrible, like a summer tire does in cold temperature, but basically none of the soft, floaty dry handling and slow response you get from a winter tire. Of course, it’s not as sharp as a car on dedicated summer tires in warm weather, but you can’t expect it to be. If I owned a Corvette, I think I’d still have a dedicated set of summers for warm weather, just for the sake of giving the car that more dialed, on-the-nose feel, but I might run these all-seasons instead of dedicated winters in the cold. For most customers, a Corvette is not a car they’re going to drive in heavy snow conditions in the winter—at most, they’ll take it out when it’s dry, and for that, the all-season works phenomenally. Calder says he’s seeing more automakers embrace these sorts of performance all-seasons following the Corvette’s lead. Not necessarily on sports cars, but things like sports sedans and high-po SUVs. These are cars where you get a lot of customers who run one tire year round, and moreseo than a Corvette, these are daily drivers, too. I think what’s possibly more interesting is what comes next. A tire program like this usually starts three or four years before vehicle production begins. When you consider the C8 Corvette went into production in 2019, this tire is, in a way, decade-old technology. So what’s the spread of performance look like in the next ultra-high-performance all-season tire? If this isn’t the tire to convince naysayers, maybe the next one will.​

​

[/td]

Word, but are they available in the 305?

The ONLY A/S tire I was able to find that fit the BW rear is the Invo. Which isn’t necessarily bad, the reviews are pretty good on them. I had been hoping for more of a straight up winter tire like the Alpin, but can’t find it anywhere.

 

[Savethemanuals]

Just like most stated, difficult to beat the specific PS4S tire. The latest Pzero PZ5 is supposed to be a phenomenal tire in the same category but I’m unable to find them in CT5 BW OEM sizes just yet.

 

[SS_Shooter]

I rode on my stock 24 CT5BW tires on many winter days with temps in the 20's and 30' without issues. Yes, they are a little slippery at cold temps, but nothing to cause significant worries. That being said, I wouldn't leave the car out overnight and let the tires get down to zero or something like that, as they might crack when you start driving on them the next morning. On other cars, I've had summer tires act really funny when frozen, like popping really loud when backing out of parking spaces.

That being said, the stock tires would be a death sentence if it snow accumulated on the roads even 1/16" based on my prior 2004/2010 CTS-V summer-tire snow-driving experiences (the 2004 wouldn't go, stop or turn in the snow - it fell in the ditch in my neighborhood lol).

I have typically switched to winter wheels/tires for the winter months, but I haven't gotten a set for my 2024 yet... My 2010 CTS-V 6MT was a BEAST with the winter tires on it! It would go through any amount of snow! I'm betting this car would be the same way. Some guy in Alaska actually owns the car now....