Snow tire pressure increase??

[Grey Ghost]

The owners manual for my 04 Mazda 3 S says to increase the air pressure 4.3 pounds over the normal 32 if you run snow tires. Anyone know the reasoning for this?

I'm running 205/55VR16 Dunlop Winter Sport M3 tires on steel wheels and the increase certainly makes them alot firmer over the 32 pounds. I'll be closely watching the treadwear...
Grey Ghost

 

[tsunami]

interesting... subbin for an answer...

 

[Pretzellogic]

I would think that the pressure increase allows the tire to better hold its shape, so that it cuts through the snow instead of sliding over it like a ski or snowshoe.

You'd be surprised how many people think that running a lower pressure in their winter tires will give them better traction.

 

[FlyinMSP]

My manual says the same. In winter it's better to have a little overinflation than underinflation. Also, most pple typically put on their winter tires in the fall when temperatures are still mild and then they forget to adjust the pressure when it gets really cold (which would be lower). By putting an extra 4 psi in the fall prevents tire underinlation later on in the winter.
Personally, I inflate my tires up to 38 psi to make sure to cut well through snow and slush...

 

[tsunami]

kind of what i figured.... i did over inflate mine but only a couple psi, will have to recheck them later and see what psi i am running still.... and probably have to increase it a bit...