tkids

I posted this on 997, but didn't get much interest, so will post it here for reference. Maybe Damon can comment on it.

I have always been under the assumption that for winter I would buy a set of winter tires to replace my summer performance tires for this time of year. I must disclose that Tirerack is my source for info and all tires for my fleet of cars.

For my 997 I purchased Pirellis and as I was looking for winter tires for the new Audi , it was narrowed to the Michelin Pilot Alpin PA3. As I waited for these tires to hit stock, Car and Driver published article "Snow Shoes" December 2009 issue. They tested all Michelins

Mich Pilot Sport A/S Ultra-High-performance all-season
Mich Pilot HX MXM4 all-season
Mich Pilot Alpin PA3 Performance Winter
Mich X-ice Xi2 snow ice

The numbers were eye opening. I just assumed that winter tires would be best for cold weather, whether snowy, dry cold, wet cold. Not so according to their tests.

In winter in the USA except for Alaska, how many times are you driving on snowy/icy roads? 10 out of 150 days!? I had no idea what I was giving up on winter dry/wet roads in the way of braking! Startling!

Here are some of the numbers:

Michelin pilot hxm4 All season

Snow: acceleration 0-30mph........10.2 secs
braking: 30-0mph ........105ft
skidpad 330 ft dia........... .28g

Wet 23 degrees:
Braking 60-0 140ft
skid: .84g

Dry 23degrees:
Braking, 60-0 130ft
skidpad, .89g


Michellin x-ice2 snow and ice

Snow: acceleration 0-30mph........7.1 secs
braking: 30-0mph ........83ft
skidpad 330 ft dia........... .33g

Wet 23 degrees:
Braking 60-0 174ft
skid: .75g

Dry 23degrees:
Braking, 60-0 158ft
skidpad, .80g

I know that there is a trade-off, but for the driving most Americans have to cope with in this country on a daily basis are winter tires right?!? I have concluded it might be better to buy an All-season tire wheelset for winter on all my AWD cars, not a designated winter tire set. People have a tendency to drive more cautious in snow and drive like their normal selves on cold dry roads, so is it worth giving up cold weather dry braking for a handful of snowy driving days?

I have never seen numbers like this and it only has clouded the issue for me, ugh!

Tirerack/Damon: Do you guys show numbers like this for winter tires??

Bob Rouleau

The results are not surprising given the conditions under which they were tested.

High performance summer tires turn into hockey pucks at temperatures of 5 deg C or about 40 deg F.

All season tires are good down to -15 C or about 4 Deg F before their rubber turns hard.

Winter tires are good to -40 C = -40 F.

As the figures show, in snow, winter tires are far superior.

If you don't worry about snow and temperatures do not get below zero F, all seasons are probably a better choice.

If you live where I do, winter tires are a must. We call 4 season tires "no season" up here with over 100 inches of snow fall and temperatures which are frequently below 0 deg F.

fbgh2o

I must confess I was surprised at the Michelin Pilot HXM4 performance... But I have to agree with Bob, when you get snow like we do up here, there is no subsitute for snow tires.

Now if only I could find some reasonably priced snows for my 996 that are in stock somewhere

tkids

I am not sure if they plow the roads in Montreal?? And tempertures look pretty mild there to average temp numbers. But I am sure you have below zero days as Colorado does. Even when I lived in Lake Tahoe, with 300" av of snow and one of the coldest places in the USA, you would still only need Winter tires on a dozen days of winter.

I find the numbers surprising becuase when you see Winter Tires advertised, there are no numbers or statements saying your better off with all seasons if your temps are not near 0 degrees everyday of winter and your roads are MADE of snow!

Bob Rouleau

Montreal is a city of 3MM people. Yes we plow the roads. On the other hand when you get 10 inches of snow overnight the snow removal crews can't cope instantly. Winter tires are now mandated by law since 4 season tires cannot cope with a hill and even 2 inches of snow - often they plow but an hour later there is another few inches of snow. With winter temperatures which are often in the blow zero F range, anything but real winter tires are a hazard which is why they are mandated by law - no exceptions. Montreal spends over 100 million a year on snow removal.

I'm not sure what "average" temperatures you are looking at, but many of us chose to ski in Colorado or Utah because it is too damn cold here

Best,

tkids

Bob, sounds about the same here with winter conditions and its maintenance. However, I don't like the fact that when those nasty days of winter which are the minority of days. So for the majority of winter, it is cold, 25 degrees and dry and then it is going to take me much longer to stop! 60-0.....18 feet longer, ouch!

This is a tough call.

But let's be honest about why you come down to ski.........we got better Micro brewed beer

brad@tirerack.com

I understand the difference in braking and acceleration in snow, but on a below freezing morning I'll take the snow tires on black ice over an all season tire any day. The numbers may sway you to believe the all seasons might suit your needs better, but why do you really buy snow tires? To have the best traction in the worst conditions. A little better acceleration and braking on clear days isn't worth a hill of beans if you cannot get home on a really bad evening after work, when you really wished you had a better tire.

No tire gives you everything, and ultimately it's up to you to decide what's most important from one. But from a sales standpoint I can tell you of very few people who were glad they bought all seasons over snow tires after a white knuckle ride home one day.

Take a look at this test, it's a fun example of just how much different they can be.

tkids

Damon, thanks for your info. I use Tirerack as I stated above for my info and you guys are who I buy from.

That said. It is all fine and dandy when you are on Black ice/Snow/Ice, but the majority of roads in winter cold and dry for most days and do people know that their stopping distance with winter tires on cold dry surfaces is compromised?

This is my only point. I know winter tires are better for the conditions you and Bob talk about, but what about the dry cold roads. I bet most people buying winter tires don't know what they are giving up when they leave their All-seasons behind.

I have never seen complete numbers as C&D show. You always see how the tires benefit you in the extremes, not necessarily the norms. As Tirerack as my main source for educating myself about tires, I have never seen numbers that give you the total picture, as C&D just published.

If a husband buys his wife Winter Tires and puts them on her car, does she know it is going to take her 18ft longer to stop on a dry road at 23 degrees. I say not!

malmasri

I have read that article and I still agree that the best snow tires are the M ice X..afterall who would not want these tires in the snow....I have seen a lot of cars fall in ditches in snow, rarely in the dry..Best part is when I plough my Cayenne with the ice x on it, thru the snow as if these roads are dry and everyone is going at a snaile's pace including law enforcement....for me it is the only way to go...Now all I need is a snow storm to enjoy

wzlc

Thank you for sharing,it is useful.

aron in toronto

This is why snow tires are required in Montreal.




Montreal has great snow removal and pretty aggressive drivers compared to Toronto. For every day driving in snowy conditions it's hard to beat dedicated snow tires.

http://www.youtube.com/watch?v=wc45-ajpWDw

tkids

It looks as most people missed the point of my post. Nothing to do with bashing snow tires in snow!

Let me simply state, that what I didn't know is the stopping power you lose in dry cold weather. A little stat that is not advertised anywhere I can find.

Just wanted to give a heads up, so when Gramps pulls in front of you as you are driving down a "Dry" street at 60mph or 100kph, it is going to take you 18-28ft longer to stop

Mike Murphy

Interesting read, and I agree that the OP point was missed. I live in Chicago, and it's currently snowing. I was looking to get some snow tires, but given that most of the time, roads are plowed, and most of the time, it's well above 0F, I might not need true snow tires. It's currently 31F here.

I guess the point is that tires are a trade-off. We have to match the temperature to the tire, and everything else is a trade-off. If roads are usually plowed and rarely below 0F, then maybe tires that perform to -40F are not a good choice for temps in the +40's.

aj986s

FWIW, if storage space is feasible, I'd recommend getting a cheap set of narrower rims for winter tire use. In addition to the tread compound of snow working better at low temps, a narrower tire will also give you more bite in the snow/ice, because the weight of the car is sitting on smaller footprints. A problem with wide tires is the large contact patch makes it easier for the tire to float on the snow. Plus, some of the performance rim sizes mandate much more expensive (and limited choice) tire options. While snow tires are great in the winter, they're compound is quite soft, and they wear quickly in the dry. I suppose dismounting/mounting tires on the same set of rims is doable. But for DIY, swapping rims is easy when the weather calls for it.

equ

Good general point, but you are skipping an intermediate entry, the winter performance tire. They are pretty close to the all-season on dry and wet and the precision feel on snow/ice goes beyond the numbers captured. The best winter choice for folks who encounter mixed conditions. Have had them for five winters now and would not go without them.