PSS and Cold Weather

[JimD]

Originally Posted by 128Convertibleguy

Not that surprising, since they worked at warming up the PSS with, presumably, hard cornering.

"they kept cornering with the PSS until it heated up and got better cornering at 57 and about the same cornering at 20 degrees as the all season"

The real test is when you're doing actual driving, which is mostly straight line cruising. The PSS won't do as well there in 20 degree weather.

It's a simple tradeoff on dry or wet pavement. Max performance at the limit in warm dry weather (summer tires like PSS) v solid, consistent, performance under a variety of conditions (ultra high performance all seasons like A/S 3s.).

In snow, nothing comes close to dedicated snow tires.

To get the PSS to corner over 1g (about 1.1) at 20 degrees required it to be warmed up. The author's estimate of the initial cornering was about 0.9g. That would be sufficient for me for driving on the street.

The reason I liked the braking test is there was apparently no repeated tries to warm up the tires and give us invalid data for street driving. There the PSS was worse at 20 degrees but still braked in about the same distance as the A/S 3s did at 57 degrees.

I remain convinced the issue with PSS tires in the winter is not temperature, it is snow and ice. I do not think the PSS tires will function very well on snow and ice due to their tread pattern. But at lower temperature, my experience plus the test data I have been able to find says they are OK.

[Overpar56]

I noticed a small decrease in traction last night. Temps in the low 40's and a cold rain. I was getting some figets going between lanes that at warmer temps and rain didn't occur. Nothing dramatic, but noticeable.

You know the 135s have inferior brakes so having dedicated winter tires may save the day by a shorter stopping distance.

[BrokenVert]

Originally Posted by Overpar56

You know the 135s have inferior brakes so having dedicated winter tires may save the day by a shorter stopping distance.

What do you mean inferior brakes? Inferior for track duty, maybe. But on the street theyre incredibly overbuilt.

[Hed Case]

Running PSS. First cold weather this year in Wisconsin (32F) and my flat tire warning is displaying, first the left front, two days later the right front. Have others experienced this?

John
Madison WI

[BrokenVert]

Originally Posted by Hed Case

Running PSS. First cold weather this year in Wisconsin (32F) and my flat tire warning is displaying, first the left front, two days later the right front. Have others experienced this?

John
Madison WI

You mean tires losing pressure in the cold? Thats just physics.

[Hed Case]

Originally Posted by BrokenVert

You mean tires losing pressure in the cold? Thats just physics.

I get that. But having flat tire warnings that require attention, never had that in previous cars. Is that what I can look forward to every time the temperature drops to near freezing, which is pretty frequent in Wisconsin?

[BrokenVert]

Originally Posted by Hed Case

I get that. But having flat tire warnings that require attention, never had that in previous cars. Is that what I can look forward to every time the temperature drops to near freezing, which is pretty frequent in Wisconsin?

The sensors go off when theres a change of a few psi from reset baseline. A cold night can easily do that. Ive had my light go on with a pressure gauge showing 33 psi in the tire.

[Overpar56]

Originally Posted by BrokenVert

What do you mean inferior brakes? Inferior for track duty, maybe. But on the street theyre incredibly overbuilt.

It's a joke. Others seem to think they're incredibly bad.

[135ivert]

It's been unseasonably cold here in the South-Denver area. 2* this morning. Plus, we got a bit of snow. Let me tell you what a shitshow today was. I decided to just see how it would drive in my neighborhood. It's quiet, no one else on the road - so I was only worried with bending my own sheet metal. I have a 30 ft drop down my cul-de-sac. Navigated successfully. Next street over I have a 30 ft incline. Fought the traction control all the way, but made it to the top. I thought that it was ridiculous for me to continue driving. I turned around and made it back to the bottom of my street. I only made it halfway up the street before I had to abandon.

This afternoon, I only made it one direction - backwards. It was still only 5*. I had to get up the street with my neighbor's F250 and a tow strap. Even then, I had to have a push up the driveway AND into my garage.

Bottom line is I need to find my wife a new car so I can drive my 2nd vehicle on days like this.

[Dackelone]

Originally Posted by Hed Case

I get that. But having flat tire warnings that require attention, never had that in previous cars. Is that what I can look forward to every time the temperature drops to near freezing, which is pretty frequent in Wisconsin?

You need to physically check each tire's tire pressure, then reset the TPMS to "learn" the new "target" pressure for the TPMS system. I always set my tire (target) pressures twice a year. Once in summer and once in winter.

It's not so much a BMW system as it is a mandated US system. Now in Europe TPMS are now required by Brussels. SO the GErmans are now having to live with these little things.

[BrokenVert]

Originally Posted by Dackelone

You need to physically check each tire's tire pressure, then reset the TPMS to "learn" the new "target" pressure for the TPMS system. I always set my tire (target) pressures twice a year. Once in summer and once in winter.

It's not so much a BMW system as it is a mandated US system. Now in Europe TPMS are now required by Brussels. SO the GErmans are now having to live with these little things.

The i3 has a much more sophisticated system. It actually reads individual tire pressures! I wonder if that is a result of this decision.

[135ivert]

Originally Posted by BrokenVert

The i3 has a much more sophisticated system. It actually reads individual tire pressures! I wonder if that is a result of this decision.

I had rental cars with this 8-10 years ago (I think it was Cadillac or Lincoln). I thought it was pointless. If your TMPS light comes on, check all 4 (or 5) tires. It's just good practice.