winter tire psi

[echo-francis]

i change my tire today and the max psi is 35 my summer tire was 45 can y put 45 in my winter tire ?

[Daox]

I've run 35 psi max snow tires at 50 psi before. I forget what my current winter tires are rated at for max psi but they'll have 50 in them too.

[bandit86]

I wouldn't go past max but keep an eye on them. If temperature goes up so will tire pressure

[KrZ]

I put 42psi in my 35psi summer tires without problems, but I would stick to the speed limit.

[Diesel_Dave]

Look on the tires to see what the max pressure rating is. It depends on the specific tire. Winter/summer doesn't really matter.

[ajjct]

i have firestone winterforce tires that max psi is 50

[CigaR007]

I keep my winter tires inflated at 35 psi. I want them to maintain their flexibility at cold temperatures (lower than -10c). Over-inflation of winter rubber is not something I would personally endorse. I want all the grip available on icy/snowy surfaces.

Just my 2 cents.

[brucepick]

Originally Posted by CigaR007

I keep my winter tires inflated at 35 psi. I want them to maintain their flexibility at cold temperatures (lower than -10c). Over-inflation of winter rubber is not something I would personally endorse. I want all the grip available on icy/snowy surfaces.

Just my 2 cents.

I'm going to try look at this in some detail - after a couple quick introductory notes.

First I have to say that I run my tires at high pressure. Let's just say that I start with the sidewall imprint. I do that for my summer and winter tires (Michelin X-Ice 2, rated 51 psi max).

Here's my personal favorite article on tire pressure. Says nothing about snow but it does say plenty about the benefits of increased tire pressure, including in rain: Driving Under Pressure (full article) - CleanMPG Forums

Regarding flexibility

If the tire is extremely cold, the rubber loses flexibility. Reducing air pressure does not soften up frozen rubber. You feel the flat spot as it rolls. I believe that's below about 0 deg. F. (-18 C.) Living in southern New England USA, I experienced it one time at about -5 F or -20 C (before I bought the X-Ice 2's). After 30 minutes drive the frozen tires warmed up and felt normal.

Now if the tire has low air pressure, it wants to flex (bend) when it hits a bump. But if the tire is brittle from cold, it cannot flex, so possibly could be damaged. If the tire has more air pressure, it will hold its shape. So may be less likely to be damaged by "bending" when frozen stiff, if it has more air pressure.

Higher pressure creates a smaller "flat spot" on the road. The car's weight is resting on that flat spot. Car's weight does not change while driving, aside from loading of occupants and cargo. So the same weight resting on a smaller contact flat spot gives higher pressure per square inch (or per square cm). That higher pressure gives better traction. And that is why autocross drivers run their cars at higher tire pressures. Google search on "autocross tire pressure"

[wdb]

Originally Posted by CigaR007

I keep my winter tires inflated at 35 psi. I want them to maintain their flexibility at cold temperatures (lower than -10c). Over-inflation of winter rubber is not something I would personally endorse. I want all the grip available on icy/snowy surfaces.

Winter tires are formulated for cold weather, including being made with a different rubber compound.

I see a significant drop in traction - in dry conditions, as well as wet or snow conditions - when I hyperinflate winter tires. The effect is much more dramatic than what I've seen with summer tires. So, while I still run pressures considerably above manufacturer recommendations, I do tend to run lower inflation pressures in the winter than I do in the summer.

[Ryland]

Both sets of my snow tires are also rated for 51psi so I keep them at 50psi.
From the studies I've read about tire pressure, higher pressure gives better traction on snow, ice and wet pavement, my owners manual also suggests bumping the tire pressure up for any highway driving and I have nearly 30,000 miles on my snow tires, so they are nearly wore down to the wear bars and the treat wear is dead even, no bald ridge down the center like people fear with bias ply tires that were popular from the 1800's to 1970's.