Excuse me for being a n00b, I am a new owner. I have a 70D with 19" slipstream wheels, took ownership in June. My tire pressure sits at 41 PSI cold and gets up to 42 when driving. I feel like it's not enough pressure. Am I able to use one of those gas station air pumps for tires? Or should I go to the SvC to get more air in the tires? The reason I'm asking is, I just want to make sure I'm not adding air when there's for example nitrogen in the tire.