Snow question

[Dryce]

With respect, this is self contradictory. Sipes create a multitude of edges and corners to bite into the surface, which is exactly what gives you grip in snow.

I'll repeat.

It's primarily about contact area and flexibility. People seem to get rather get caught up with the idea that it's primarily about snow grip. The actual principle of operation is based on improving contact against a normal surface in poor conditions.

 

[Doodle]

That statement is nonsensical. One is the result of the other - flexibility, contact area (dictated by both size and compound) and biting edges give you friction against the surface, whatever that may be. Friction is grip.

 

[rf065]

The Scandanavians have a saying, and we all know they experience worse winters than ours...................

"Winter tyres first, 4WD second"

My CLK trounces 4WD's on summer tyres even from a standing start in 6" of snow.

Russ

 

[st13phil]

From personal experience SLK + snow + summer tyres = leave it in the garage.

Haha

My W204 C220CDI (which was an Elegance model on 16-inch Michelin Primacy's) was reasonable in snow, although if you had to stop on an upward gradient you were pretty much done for.

When my wife had her R171 SLK350 it was on 18-inch Michelin PS2's and I drove it in light snow. When I could actually get it moving it had the directional stability of a supermarket trolley and as a result any motion at all was pretty terrifying

By contrast, my W212 E350CDI on winter tyres was superbly driveable in snow

My E63 is currently on Michelin PA4's as an insurance against snow. So far it's working

 

[Dryce]

That statement is nonsensical. One is the result of the other - flexibility, contact area (dictated by both size and compound) and biting edges give you friction against the surface, whatever that may be. Friction is grip.

Biting edges can't give you grip against a surface.

The misunderstanding with sipes is about the way they work - people get caught up with the idea that the sipes themselves give grip or 'bite' - when it's about what the sipes allow the rubber (or tyre compound) to do in conforing with the contact surface.

It's a bit like the issue with tread - which is usually about dealing with surface water as opposed to providing actual grip or bite.

 

[Doodle]

Biting edges can't give you grip against a surface.

Contact surface area of edge vs rounded object.
Assumption of incompressible surface, which it isn't, and the altering effect on the horizontal vector.

I can see I'm wasting my breath here...

 

[Dryce]

I can see I'm wasting my breath here...

Yes .... but you did mention friction at one point ..... so you get some of it.

 

[Doodle]

Yes .... but you did mention friction at one point ..... so you get some of it.

More of it than you, it seems.

 

[Dryce]

More of it than you, it seems.

Well *you* might blissfully think that.

 

[Doodle]

I'm ok with that, as long as my university and employers keep harbouring the same blissful thoughts too.

 

[Deleted member 6183]

This was what I was going to respond with to the OP's question.

The last snow we had here saw me taking my old S class to work in the nearest office/town, it was hairy to say the least with a few genuine 'breathe in I'm coming through' moments.

 

[Deleted member 37751]

work great till she reached snow deeper then the chassis

This ^^

The best winter tyres in the world can't beat ground clearance, so for the one or two weeks a year we do get snow, I'd plump for the 4x4 for this reason alone.

Having said that, when was the last time it snowed heavily south of the Watford gap?

 

[jaymanek]

My G wagen has summer tyres... Its pants in the snow.
However thats only when its really heavy sitting snow like in a car park. Doing donuts in a V8 4x4 is fun

I tried to find winter tyres in the correct size but the cost was ridiculous...
We only get a few days of really bad weather and 90% of the time the roads are clear by 8AM.

For this reason I would still use the G wagen over any other car I have.

 

[grober]

There are quite a few factors to be taken into account in assessing how good a car will perform in snow. Proper winter tyres are " the" obvious factor but overhangs, ground clearance and weight also play a part. A conservatively tyred lightweight car [ tyres not too wide or nothing too low aspect ratio] - with decent ground clearance and FWD will get you most places provided there's no silly electronic stability control strangling the engine of power.
factors typified by this video alltho both vehicles were 4wd in this case
:-
[YOUTUBE HD]qglqhHmbM6g[/YOUTUBE HD]

 

[camerafodder]

I'm ok with that, as long as my university and employers keep harbouring the same blissful thoughts too.

I'm OK with it too Doodle. The way that sipes affect grip on smooth surfaces (including snow) has long been accepted by tyre manufacturers and I can confirm that my own personal experience over many years of snow driving bear it out. Obviously they have little effect on virgin snow but once compacted they are an essential element to the makeup of a winter tyre.

 

[Mattns]

if you need to travel to work etc., winter tyres or 4x4. If you enjoy experiencing a more creative drive then stick with summer tyres and go play after the rush hour!