Winter tire psi reccomendations?

Status
Not open for further replies.
Quote:
BITOG might give you a gold star!! (Hint - I'm still waiting!!)


They give that stuff out?!?! I'm far too much a tire guy than an oil guy, I'm not worthy, heheh!!



Quote:
If we were to measure the size of the footprint of a loaded tire, then increase the inflation pressure, the footprint will get smaller. Most of the time it is the length of the footprint that changes - but occassionally, especially under extreme circumstances, the width will change.


Actually I would say the exact opposite, but I think that has to do with what is more common with the region. Here we have trucks, vans, big suv's, large sidewalls and skinnier wheels. You would need a wheel closely matching the width of a lower profile tire not to effect the width of tread contact as much as length, or at all, which I guess would be more common in your area.

Quote:
Persoanlly, I think more uninformed / low skilled drivers live in cities, and in the lower 48, and these folks are most likely to encounter slush and loose snow, and the idea of penetrating through that to get to pavement is better


Let's talk about slush and light snow. If it's shallow enough that was can possibly "cut" though to the pavement underneath, increasing psi is not needed here either, just optimum psi. If you're plowing, you're either running too low a psi completely, going too fast for the conditions, the tires are too wide (slow down), or the tires are plainly not sufficient for the task at hand. The best way through slush is to go skinny, with larger tread voids to disperse. That, and to run a psi that allows the carcass to conform to the road surface of course. .

Even if we manage to air up a tire without effecting width, it still doesn't change the fact a 7" wide tread at 35psi is plowing just as much slush and snow as a 7" wide tread at 40psi. The only difference is the 40psi is now less pliable and not able to conform to the road surface as well. The tread voids haven't changed, the road conditions haven't changed, the tire still won't eject the slush/snow any better. It's now producing less traction and has less time to eject debris than it did with a longer footprint, which may actually lead to increased hydroplaning, not reduced.

80% of all winter accidents are related to a loss of lateral grip. Cornering, sliding left or right, a lack of lateral stability/control. I thought for sure it was braking, go figure.
Raising psi also will effect lateral grip negatively since the tire cannot produce the same traction being less pliable, all the more reason not to increase psi.

Width is the problem with slush or that light covering of snow, not length or pressure of the contact area. You need to utilize all available traction the tire can produce, increasing psi beyond optimum does the exact opposite.

I wish I didn't have to work, a beer would be nice after all this typing!!

Maybe we agree to disagree, it has been fun though, I do enjoy talking tires, heheh!

Cheers,

Mike.
 
Quote:
It may be a data point arguing for lowered pressure in that situation, but it hardly counts as a definitive "nip in the bud," considering the anecdotal nature of the story.


I agree, it's not etched in stone or anything, it's just an example of how I managed to drive to my sister's house with junky tires through ice, snow, and slush all mixed in a greasy layer of slop. It was maybe 1"-2" thick at the most, seemed relative to the discussion at hand IMO, and dropping psi worked.

If it was just slush on the paved road I would of done nothing, all the other vehicles would of mashed it to water long before I got out on the road.
 
I have been playing around with tire pressures for the last couple days now that the snow has started to come down.

Went skidding through the neighborhoods first at 36 psi, then 33 psi, then 30 psi. Want to know what I really found? Not much of a difference at all but I did find that it stopped better with a higher psi. I will probably keep it at around 35 psi because I realized that most of the main roads are kept sanded and shoveled and that having this pressure is best suited in most situations.

The only time i would drop the pressure is if i'm stuck in a ditch with deep snow.

This test was completed within my neighborhood, in my car, in my climate, with my tires, even the readings were done with my pressure gauge, so in no way should this be regarded as your fact.
 
Last edited:
Originally Posted By: byez
I have been playing around with tire pressures for the last couple days now that the snow has started to come down.

Went skidding through the neighborhoods first at 36 psi, then 33 psi, then 30 psi. Want to know what I really found? Not much of a difference at all but I did find that it stopped better with a higher psi. I will probably keep it at around 35 psi because I realized that most of the main roads are kept sanded and shoveled and that having this pressure is best suited in most situations.

The only time i would drop the pressure is if i'm stuck in a ditch with deep snow.

This test was completed within my neighborhood, in my car, in my climate, with my tires, even the readings were done with my pressure gauge, so in no way should this be regarded as your fact.


There's no better way to find what psi works the best for your vehicle, that's how I do it too. There is no chart to tell you, thanks for sharing the info!
 
Status
Not open for further replies.
Back
Top