Michelin Runflats; PS2 ZP & A/S ZP in Snow
12-29-2012, 11:18 AM
#1
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St. Jude Donor '13
Michelin Runflats; PS2 ZP & A/S ZP in Snow
Each winter I usually put the A/S runflats on our C6 coupe, for the January drive from Chicago to Florida.
But last winter was very mild, and we total 4k-8k miles on the car with only the first day in possible snow, so I left the PS2 runflats on. The first day was cold but the roads were clear, and the tires worked well. Grip was less than on a warm summer day, of course, but normal highway driving was, uh, normal. I was impressed with how those tires performed in cold temps, but they never were driven in any actual snow. In ordinary rain, they are outstanding and probably better than the A/S.
This winter seems not so mild, but I'd really like to have the PS2's for all that warm weather driving down south. So far, I've left them on the car but have not gone outside my driveway since the salt hit the roads.
This morning we woke up with about 1/2-3/4 inch of light fluffy snow on the driveway. Temperature was a few degrees below freezing. I let the car idle in the unheated garage while I exercised all the various switches and controls for about 10 minutes, then backed out and tested the PS2 runflat traction in the snow. Tread depth was about 5/32" on the rear tires.
They were awful. Initially, I got started ok in the driveway and was getting up the inclined part ok also. But when I stopped on the moderate incline and tried to get going again, the wheels just spun. In fact, even with the A6 in drive at idle, the car was slowly sliding backwards down the slight slope. I backed down onto the flat part of the driveway and went to pull back into the garage, could barely do even that. It seems that once the tread blocks got filled with snow, they never released it and my "grip" was snow trying to grip snow.
Summary:
The Michelins PS2 ZP runflats do reasonably well in cold temps with dry pavement, but the A/S are somewhat better.
With any snow, forget the PS2's and get the A/S on your car.
Here's the link to my previous snow test of the Michel A/S:
http://forums.corvetteforum.com/c6-c...n-a-s-etc.html
But last winter was very mild, and we total 4k-8k miles on the car with only the first day in possible snow, so I left the PS2 runflats on. The first day was cold but the roads were clear, and the tires worked well. Grip was less than on a warm summer day, of course, but normal highway driving was, uh, normal. I was impressed with how those tires performed in cold temps, but they never were driven in any actual snow. In ordinary rain, they are outstanding and probably better than the A/S.
This winter seems not so mild, but I'd really like to have the PS2's for all that warm weather driving down south. So far, I've left them on the car but have not gone outside my driveway since the salt hit the roads.
This morning we woke up with about 1/2-3/4 inch of light fluffy snow on the driveway. Temperature was a few degrees below freezing. I let the car idle in the unheated garage while I exercised all the various switches and controls for about 10 minutes, then backed out and tested the PS2 runflat traction in the snow. Tread depth was about 5/32" on the rear tires.
They were awful. Initially, I got started ok in the driveway and was getting up the inclined part ok also. But when I stopped on the moderate incline and tried to get going again, the wheels just spun. In fact, even with the A6 in drive at idle, the car was slowly sliding backwards down the slight slope. I backed down onto the flat part of the driveway and went to pull back into the garage, could barely do even that. It seems that once the tread blocks got filled with snow, they never released it and my "grip" was snow trying to grip snow.
Summary:
The Michelins PS2 ZP runflats do reasonably well in cold temps with dry pavement, but the A/S are somewhat better.
With any snow, forget the PS2's and get the A/S on your car.
Here's the link to my previous snow test of the Michel A/S:
http://forums.corvetteforum.com/c6-c...n-a-s-etc.html
Last edited by Gearhead Jim; 12-29-2012 at 12:10 PM.
12-29-2012, 01:20 PM
#2
Race Director
5/32ds is really not that much tread though as A/S tires can become squirelly around that time also. But your test does make sense though since Michelin doesn't even say they are good below 40 degrees at all.
Chris from Callaway seems to have some winter mileage on his test car in GS sizes.
Chris from Callaway seems to have some winter mileage on his test car in GS sizes.
12-29-2012, 02:38 PM
#3
Team Owner
5/32ds is really not that much tread though as A/S tires can become squirelly around that time also. But your test does make sense though since Michelin doesn't even say they are good below 40 degrees at all.
Chris from Callaway seems to have some winter mileage on his test car in GS sizes.
Chris from Callaway seems to have some winter mileage on his test car in GS sizes.
12-29-2012, 09:19 PM
#4
Race Director
It all depends on your type of driving. Drive in snow (not light snow) and you'll need at least 4 to 5/32ds of tread with a real good winter/A/S tire. Michelins start around 9-10/32ds. My Impala SS has the Sport A/S non ZP version. Tires have around 30k miles on them but around 5/32ds of tread. It has snowed recently here in Utah and while they got me where I needed to go and didn't get stuck they are more "interesting" than in years past. I'll probably have to replace them before next winter.
12-29-2012, 09:59 PM
#5
A summer performance tire does not perform well in the snow....ok...Thanks
12-29-2012, 10:12 PM
#6
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Each winter I usually put the A/S runflats on our C6 coupe, for the January drive from Chicago to Florida.
But last winter was very mild, and we total 4k-8k miles on the car with only the first day in possible snow, so I left the PS2 runflats on. The first day was cold but the roads were clear, and the tires worked well. Grip was less than on a warm summer day, of course, but normal highway driving was, uh, normal. I was impressed with how those tires performed in cold temps, but they never were driven in any actual snow. In ordinary rain, they are outstanding and probably better than the A/S.
This winter seems not so mild, but I'd really like to have the PS2's for all that warm weather driving down south. So far, I've left them on the car but have not gone outside my driveway since the salt hit the roads.
This morning we woke up with about 1/2-3/4 inch of light fluffy snow on the driveway. Temperature was a few degrees below freezing. I let the car idle in the unheated garage while I exercised all the various switches and controls for about 10 minutes, then backed out and tested the PS2 runflat traction in the snow. Tread depth was about 5/32" on the rear tires.
They were awful. Initially, I got started ok in the driveway and was getting up the inclined part ok also. But when I stopped on the moderate incline and tried to get going again, the wheels just spun. In fact, even with the A6 in drive at idle, the car was slowly sliding backwards down the slight slope. I backed down onto the flat part of the driveway and went to pull back into the garage, could barely do even that. It seems that once the tread blocks got filled with snow, they never released it and my "grip" was snow trying to grip snow.
Summary:
The Michelins PS2 ZP runflats do reasonably well in cold temps with dry pavement, but the A/S are somewhat better.
With any snow, forget the PS2's and get the A/S on your car.
Here's the link to my previous snow test of the Michel A/S:
http://forums.corvetteforum.com/c6-c...n-a-s-etc.html
But last winter was very mild, and we total 4k-8k miles on the car with only the first day in possible snow, so I left the PS2 runflats on. The first day was cold but the roads were clear, and the tires worked well. Grip was less than on a warm summer day, of course, but normal highway driving was, uh, normal. I was impressed with how those tires performed in cold temps, but they never were driven in any actual snow. In ordinary rain, they are outstanding and probably better than the A/S.
This winter seems not so mild, but I'd really like to have the PS2's for all that warm weather driving down south. So far, I've left them on the car but have not gone outside my driveway since the salt hit the roads.
This morning we woke up with about 1/2-3/4 inch of light fluffy snow on the driveway. Temperature was a few degrees below freezing. I let the car idle in the unheated garage while I exercised all the various switches and controls for about 10 minutes, then backed out and tested the PS2 runflat traction in the snow. Tread depth was about 5/32" on the rear tires.
They were awful. Initially, I got started ok in the driveway and was getting up the inclined part ok also. But when I stopped on the moderate incline and tried to get going again, the wheels just spun. In fact, even with the A6 in drive at idle, the car was slowly sliding backwards down the slight slope. I backed down onto the flat part of the driveway and went to pull back into the garage, could barely do even that. It seems that once the tread blocks got filled with snow, they never released it and my "grip" was snow trying to grip snow.
Summary:
The Michelins PS2 ZP runflats do reasonably well in cold temps with dry pavement, but the A/S are somewhat better.
With any snow, forget the PS2's and get the A/S on your car.
Here's the link to my previous snow test of the Michel A/S:
http://forums.corvetteforum.com/c6-c...n-a-s-etc.html
12-29-2012, 10:47 PM
#7
Drifting
It can be thought of this way. If you take a clump of snow and compress it into a hard snowball, you get very little friction if you rub against the surface. However, if you grab one half of the snowball and try to shear it from the other half, it's almost impossible to do that. Traditional tread winter tires work in this way - the tread voids allow a large amount of snow to be compressed into the zigzag void (this is why the voids in snow tires are shaped this way), which kind of acts like holding the top of the snowball. The drive force then works through shear.
All season and summer tires have straight tread voids which allow the compressed snow to slide in the void, and the shallow depth doesn't allow enough grip of the compressed snow surface. Then, you're dealing with just flat rubber on compressed snow mechanical friction, which is very low.
Just a fine point - the rest of what you post is right on in terms of tire use.
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Spencemoney (08-23-2021)
12-29-2012, 10:55 PM
#8
Race Director
With a car that light, having that much power on a tire that wide, it a would seem like a crapshoot at best. I have the PS2 A/S ZPs buts thankfully I do not have to test them in the snow. Good thing because we were just blessed with 18 inches of the nasty stuff the past couple of days.
12-29-2012, 11:20 PM
#9
Race Director
The main thing I don't like about driving in the snow is that you cannot see potholes and curbs among other things. I wouldn't even consider driving the C6 in snow without pure winter tires though. Less than 1 inch really is not much snow contrary to what Texans think.
