Nokian makes admirable tires. Would liked to have gotten them for my Honda if they were available. *NM*

Daytime temperatures have been dropping into the low 50s recently, and I've noticed the "low speed full-lock front tire skipping" beginning to occur. Porsche recommends going to non-summer tires when it's below 45º, but it seems to me the skipping is indicating an upper temperature threshold for compromised overall traction. As the forecast is showing consistent ≈ 45º daytime highs for the next several days, I think it's time to change to the PA4s. (Summer fronts: N-spec Goodyear F1 Asymmetric 2, 235/40-19s on a 981 Boxster S. Something like 30-35,000 miles on the summers, so maybe compound aging is a factor.)

Minus 40 degrees... Is that Fahrenheit or Celsius?



Edited 1 time(s). Last edit at 11/18/2015 05:26PM by Laz. (view changes)

Although, as a general rule, Porsche may be right with 45 degrees F (7 degrees Celsius), if your tires are losing traction at your current temps, switching over to winters would be a good idea.

[www.theglobeandmail.com]

Minus 40 degrees... Is that Fahrenheit or Celsius?

Well, not snow tires, but my 981 TPMS display insisted that, to synchronize the sensors in my new 18' wheels, I had to select the '18 inch winter tire' setting.


20" and 18"


18"

Quote
Roger987
Well, not snow tires, but my 981 TPMS display insisted that, to synchronize the sensors in my new 18' wheels, I had to select the '18 inch winter tire' setting.


20" and 18"


18"

I may have missed this earlier--which 18" wheels are these and what tires on on them? BTW, they look great.

Nope, Mike, you didn't miss it. I'd not posted these pics before. These are 18" wheels off a 981 Cayman. Three had 250 miles on them, and the fourth tire was brand new

The 20" wheels are great.. except on my local roads, where the potholes have grown potholes. The 18's offer a fair bit more sidewall height, and with that, an improved ride.

Mike, I was guided by your post on another board, where you described your use of 18" 987 wheels on your 981S, when tracking. I reckoned that if 18" 987 wheels fit your 981S, then I'd be safe with the 981 Cayman 981's on my 981S.

My 'new' wheels came with factory TRMS sensors, which my car's computer has now 'synched'.

The tires are Goodyear Eagle F1 Asymmetric 2, 235/45 and 265/45.



Edited 1 time(s). Last edit at 11/20/2015 01:03PM by Roger987. (view changes)

IIRC, someone else on this board that ordered a 981B a few years back added those wheels to their car.
Combined with PASM, I would think you'll have a more comfortable ride.
FWIW, I liked the GY F1 Asymetrics we had on our 987.

Quote
MikenOH
IIRC, someone else on this board that ordered a 981B a few years back added those wheels to their car.
Combined with PASM, I would think you'll have a more comfortable ride.
FWIW, I liked the GY F1 Asymetrics we had on our 987.

In designing the 18" wheels for the 981 Cayman, Porsche didn't stray far from the previous generation's 17" design.

10th point:
I'd still like to see deeper voids on snow tires. Not too deep because of overall dry road handling concerns, but N-spec Michelin PA4s aren't significantly deeper than the summer tires. I think the now-available (for 981s) Continentals are similar. Yeah, not scientific, but my contention nonetheless.

5th point: contact patch area is fairly constant when the only variable is width. The narrower the tire, the greater the longitudinal dimension becomes, which I believe is advantageous on liquid water and snow-coated surfaces insofar as directional control. To this contention, I offer the article at this link. Admittedly I only glossed through as my head began to spin, but I think it supports my contention:
[www.performancesimulations.com]

Minus 40 degrees... Is that Fahrenheit or Celsius?

tires were in the '30s and '40s and yet people drove in the snow on them. They had a lot less tread depth and even sometimes no tread at all. Wheel width on a Model A was 3" IIRC.

Based on the Model T:
[www.modeltfordsnowmobile.com]

Minus 40 degrees... Is that Fahrenheit or Celsius?

The skis at the front wouldn't be much of a problem on a Boxster.

You'd have to make some fancy modifications to fit 2 wheels under each back fender though.

[chrisescars.blogspot.com]

Minus 40 degrees... Is that Fahrenheit or Celsius?

Exactly! Takes a keen eye for detail to tell that from a stock 928.

Yea, they lose grip, but they had much more to begin with. I'm talking 40s too.

I use snows for, well, snow. That said my mantra has always been Thanksgiving to Easter.

Grant

Grant

gee-lenahan-at-gee-mail-dot-com

and, barring excessive wear in hot weather, could probably work pretty well all year in normal street driving. In the cold, they feel just about as good as the summer tires. Their downside is they could be better as true snow tire. Some of this issue may be due to the extreme width as fitted to Porsches. A couple Decembers ago I visited friends in Montgomery, Alabama. By the time I got into the state, the temperature was well over 80.* I worried about cooking the tires, so finished the last couple hundred miles going uncharacteristically slow, ten under the limit. And, in contradiction to the other post's linked article, I would like to see somewhat deeper voids. The next time around, I'll try the now-available N-spec Continental winter tires, although I suspect it won't make a big, if any, difference.

* On the way back it was snowing in the Shenandoas, so I took got over to I-95 at Richmond. It was snowing just north of there, too, but the temperatures, snowfall, and grades were less adverse. I was glad to have winter tires on for whatever help they would give.

Minus 40 degrees... Is that Fahrenheit or Celsius?

Grant

gee-lenahan-at-gee-mail-dot-com

Unfortunately, although they come in front & rear 18" sizes that would fit a base 981 Boxster (and perhaps the S, too) there isn't a seemingly great enough difference in width to yield functionally advantageous contact patches. Even if 18s were available in 2012 when I got the 19" Michelins, I couldn't be certain they would fit (offset, etc) the S. It sure would've been cheaper. At the time I was taking the big inaugural cross-country trip, TireRack hadn't yet gotten their hands on a model to confirm winter tire fitment. It's ironic that I passed close enough to their hq that I could've had them use my car! When I did order the Michelin tire/wheel package I told them so. At least one more season can be gotten out of the Michelins, and then I'll try the Continentals, unless some appropriate alternative comes along.

Minus 40 degrees... Is that Fahrenheit or Celsius?

They have basically discontinued most low-profile 16s, which is what i run on the base car.

I may put on Nokian WRs. A snow-biased all season.

Incidentally the Dunlops are good in snow, but what i really like is that they are a very good dry pavement car, with vastly better sidewall integrity and feel than the Michelins or Bridgestones.

Grant

gee-lenahan-at-gee-mail-dot-com

Minus 40 degrees... Is that Fahrenheit or Celsius?

The weather in New England has been quite warm this year, but next week looks like some colder temps will arrive.
Still, doing the Summer/Winter tire swap in mid-Nov is about 3 weeks later than previous years!!!

Keep in mind the winter tires are the same sizes, front and rear, as the summer tires. One other phenomenon that was beginning to occur before the change was axle tromp, especially on initial, even moderately hard takeoff. The last time was after upshifting to 2nd on brisk, not hard, acceleration. The tromping occurred after 2nd was engaged and the engine revs were rising to 5000 plus, perhaps having to do with being within the torque peak and moving toward horsepower peak.
The rear tire tread depth is noticeably worn after three seasons, and next year N-spec Continentals will be fitted, at least to the rear.

Minus 40 degrees... Is that Fahrenheit or Celsius?