Couple of questions when looking for winter tires:

1. What are the trade offs between Performance Winter Tires and Studless Ice and Snow? (driving S5 in Western PA/West Virginia some NE Ohio) The studless Ice and Snow seem to be less expensive than the performance winters.. Just not sure what direction to go.

2. The stock wheels/tires on the S5 are 19in 255/35.. I am thinking about going down to 18in winter wheel/tire combo's. Noticed that the standard 18in package TireRack comes up with are 245/40 R18's - but it also shows an option for a 225/45 - and aside from being about $20 less per tire (for Blizzak LM-25's) the narrower tire should be better in winter, correct? Any downside to the narrower tire?

Will I need anything else to fit a 225/45 winter wheel/tire combo? (spacers, etc) - besides TPMS?

Any other considerations for a Dec-March tire?

Much appreciated..

 

first off, a performance winter tire is just that...available in higher speed ratings (stiffer sidewalls) for...high-speed cruising and most important the tread pattern very aggressive for clearing snow, slush, many many sipes and a compound that'll stay soft(er) at temps below 40 F without sacrificing too much in the handling.
Typically you want a 'narrower' profile to go "through" the snow v. a wider pattern that'll cause you to go 'up and over' the heavier snow so narrow is good here if available. Dunlop M3 & 3D a great choice. Nokian makes probably the finest line of snow, ice/snow, high performance AS (I think the only AS with the "severe snow" rating symbol).

Studless ice/snow...soft, squirmy sidewalls, many thousand sipes purpose built for ice traction. They have lower speed ratings. This design is for #1 traction on ice & snow. Performance on dry is the last consideration...IT IS A MUSHY TIRE...on purpose...as it follows the contours it rides on. If you use them, your first drive on dry roads will make you think they're about 10# low on tire pressure...that's how soft and mushy they'll feel and no matter how much air you put in, they'll stay mushy.
If you don't 'need' studless ice tires, stay away from them.

If you live in an area where there's marginal snow localized snow (lake effects ), maybe better off doing the Nokian WRG2 for year around all season performance traction without the bother of changovers (a PITA). Interestingly enough, this tire has a great treadwear lifetime, as most Nokians seem to have.
You are the judge on "what you need" governed by your local average winter conditions and whether you "want" to drive for cold wx activities to the slopes or you 'need' to drive to work. If you downsize diameters, be sure the rims fit over the brakes. .02

 

Especially for putting the downside of the ice and snow in a meaningful metaphor - 10# down in pressure/mushy..

 

and I figured there woulda been an improvement (between the time gap) with all the new tire tech available, but not at all...and why I stressed the 'mushiness'. You wouldn't be happy with them on your 'S' for sure.
If you get a chance, check out the Nokian WRG2's, maybe for both your setups...Good luck.

 

Loosing control of the car in dry or wet conditions because the performance has been degraded so severely from your summer set up is a very real posibility.

Performance winter would be my pic for an S5 in your area. You guys get lots of big snow falls. I live in SE MI and we don't get many big snow falls so I run performance A/S tires in the winter on my Audi and summer tires for the summer. I just make sure I get the best A/S tire for snow and it makes for a great performance winter tire that has much better dry/wet grip than a true performance winter, but not as good snow traction.

 

The biggest is that you loose dry and wet grip due to a smaller contact patch. A narrower tire is only good for loose deep snow or slush when you need to cut through the loose stuff and get down to the surface of the road. A wider tire is better for dry/wet and hard pack snow or ice.

I would go with 245's over 225's on your car. You will already be giving up dry/wet grip by going with a performance snow tire in comparison to your summer 255's then you will give up even more if you go to a tire that is 25mm narrower as well.

Last winter I actually ran a wider tire in the winter. I had been running 235 A/S tires in the winter but they were worn out and I needed something new to run in the winter. I put the 255 A/S tires from my wife's car on mine for the winter since she was running winter tires. I did not notice any loss of traction in snow like I thought I would.

 

Look for T speed ratings, like the Nokian Hakkas or the Hankook iPike w409. These are better in snow/ice than the performance winter tires without giving up as much on the dry as something squishy like the Blizzak Q rated tires.

 

Thanks - I figured there must be a trade-off somewhere..

 

Keeping it in perspective, this is for cold & foul wx consideration. Performance is secondary.

 

negative on the wider tire is better for the ice.