Did you know that naturally tires lose about 1 psi of air pressure each month? Did you also know that tires lose 1 psi for every ten-degree drop in air temperature? This means tires can easily be running several pounds under-inflated by the time winter comes along. You might not notice as the change has been gradual over the months.
... just thought i'd add this in

 

it's common for tires to lose about 1 psi per month but not always...i have one set of tires that loses around 1psi per month...i have another set that loses less than that

 

wow...I totally forgot about this..I will def have to fill up my tires...in buffalo we have gotten a **** load of snow so far and now that im boost'd it is like driving on an ice rink