U can use start spray. just 4-5 quick rounds insite the tire whait 2-3 secs and light it I usualy use a lighter and the spray can. It is better to remove all cabs from the wheel so all the extra air will be able to excabe the tire without damaging anything. You can allso us co2 to inflate it but then U may have to lift the tire up,
when I am driving in snow I go as low as 1,5 psi but the reason for not to take to much air out of the tires is that when there is not enough air in them they will overheat so if you are driving in snow it should be ok but not on high way, that is the reason for everyone has a air pump in theyr cars.
Belife me I know this stuff.
