Higher tire pressure and winter handling?

[TwoBearWisconsin]

I have just under 3000 miles on my Yaris so far, and I'm averaging around 37-38 mpg. I'd really like to see if I can do better. I know that increasing the air pressure in the tires is one way to up the mpg, but I'm wondering if doing it now is a good idea. How does increasing air pressure effect winter/snow handling? Also, what is a good pressure to aim for?:confused:

Thanks,
Willy

[R2D2]

I run mine at 55 psi as I have for some time now. The max pressure on the sidewall is 44 psi so I do so at my own (minimal) risk.

I slowly increased from the recommended 32 psi on up. Increasing tire pressure is an easy, cheap and very effective way of increasing fuel mileage. Ride is a little stiffer but the tires are wearing well and I have no complaints in the grip department.

I think the car is great in the snow-no complaints at all.

R2D2

[BailOut]

I run anywhere from max sidewall to 60 PSI year round. I do just fine on mountain roads that see up to 400" of snow each year. In fact, I often pass by lifted 4x4s with monster tires on them which are stuck in ditches and snowbanks, waiting to be pulled out by the Highway Patrol.

Just follow the basic tenets of snow driving:

- Accelerate and brake slowly and gradually.

- Give lots of following distance.

- Make adjustments slowly and deliberately. Don't twitch.


.. and you'll be fine. :smile:

[Hershey]

use close to 37 p.s.i. during colder months . Lose about 5 p.s.i. during coldest times and gain about same when temps rise some . Is a hassle when temps swing up and down . These are studded snows . Don't want to much air otherwise less tire contact and dancing on studs for less stability ( especially cornering ) and wear on studs . Usually check pressure once a week or few weeks when have memory lapse :biggrin: .

[Yaris Hilton]

I'm running the original tires at the 44 PSI max sidewall pressure. I've done some driving in snow recently, and had no problems. I drive like BailOut said, and went by lots of trucks and 4x4s that were having problems because their drivers think it's all about equipment, not technique.

[1stToyota]

Last year a guy here [can't remember which member] did his own private test on a parking lot. He hit the brakes with the proper amount of air, then pumped up the pressure and retested. His conclusion was that the extra distance he traveled with the extra pressure could have been the difference between wrecking or staying safe.

I've always heard that you let a few pounds out in winter to get maximum traction, so yeah, only makes sense to get double the psi in those tires! Might save a few cents at the next fillup. :wink: :clap:

[127.0.0.1]

Last year a guy here [can't remember which member] did his own private test on a parking lot. He hit the brakes with the proper amount of air, then pumped up the pressure and retested. His conclusion was that the extra distance he traveled with the extra pressure could have been the difference between wrecking or staying safe.

I've always heard that you let a few pounds out in winter to get maximum traction, so yeah, only makes sense to get double the psi in those tires! Might save a few cents at the next fillup. :wink: :clap:


low pressure will keep you from sinking, and will grab snow better, may be better on ice
high pressure will cut through stuff and reach pavement better, may kill you on ice

so, it all depends on the specific conditions at hand, whether high or low pressure is better or worse.

fact is, the vehicle handling and dynamics and safety ratings and VSC is designed and engineered and calculated for stock tire at stock pressures

is that enough improper grammar ?

[1stToyota]

low pressure will keep you from sinking, and will grab snow better, may be better on ice
high pressure will cut through stuff and reach pavement better, may kill you on ice

so, it all depends on the specific conditions at hand, whether high or low pressure is better or worse.

fact is, the vehicle handling and dynamics and safety ratings and VSC is designed and engineered and calculated for stock tire at stock pressures

is that enough improper grammar ?

That's what I run; stock pressure...even says so right on my oem Goodyear sidewall, across from the "44 psi max" warning, to follow owner's manual and vehicle placard for proper inflation. :smile:

[TwoBearWisconsin]

Well, I just bumped the psi up to 40 last night, so we'll see if there is any significant increase in fuel economy. I had been running 32. Max is 44.

So far, I don't see any significant change in the ride or handling characteristics of the car. Maybe a little stiffer ride. I'm taking a trip of a couple hundred miles this weekend, so we'll see what happens.

[schleppy]

I only run 35psi in Firestone Winterforce tires, but I have had zero issues with snow traction. I've driven out of almost 5" of snow/slush at one point.

[Aothachos]

i run mine at 34 all year around no problems

[dean_park]

My Element spec is 32Fr 30Rr (or the other way around, I forget). I ran it 42/40 on a long road trip and notice some good mileage (for a cube). On the way back, we hit snow and it felt slick like I was sliding all over. Fresh snow on dry road, barely freezing, so it was possibly more ice on the road than snow. I pulled off and aired down to spec and it felt much better. I have no clinical trials to go on, but I felt more confident with the factory spec pressure after. In the spring, I'll probably air it up a bit. The tires are Bridgestone duelers 225/75/16, so a little different than my Yaris. I run 42/42 in the Yaris on the 185 width tires and I think it's OK in the snow.

[TwoBearWisconsin]

Got my first 40 mpg when I filled up today - and that was even with a 300 pound passenger on my trip this weekend :)

[Altitude]

^^ Grats! I'm still hoping to hit that magiv number myself but I have a lot of things working against me where I live.

[SpaceShot]

I run mine at max sidewall, which is 44 for the all seasons, and 54 for the snows.
(not intending to restart the sidewall vs. door placard here, there are numerous threads on what the ideal pressure is)

It is well worth your $360 ($400 w/ spare rims) to put real snows on if your going to deal with more than 2-3 storms per season.

But BailOut's last point is key...Don't Twitch!
Reacting too fast or overreacting to slight slipping makes it far worse.
Treat it like skiing, it is OK to slip slightly, lightly adjust and then get back under full control.
Good blizzard or ice storm driving is similar to hypermiling, a light even pressure is best. The difference is in slick conditions you are monitoring for tire grip instead of optimum engine revs.
It takes a lot of experience not to pull hard on the wheel or jab the brake as soon as you start sliding, but having some confidence in yourself and the car to be able to ride out small slips, will help keep you steadier and prevent turning a slip into a spinout or crash.

[sbergman27]

I recall that in the early 80s, Goodyear did testing of winter driving at various driving pressures. They concluded that contrary to "common knowledge", traction increased with increased tire pressure. i.e. the folks who were letting air out of their tires to "put more rubber on the road" were *reducing* their traction on ice and snow.