Let's not compare pure nitrogen with something you think might be nitrogen. Mine comes right out of the bottle, so it's not wet or mixed off. Once I change my tire and seat the bead, I put about 20psi nitrogen in and then bleed it off as sort of a purge. The I refill it to full pressure, I never touch it again until the tire comes off (a year to 1-1/2 years). It does not leak out. I have 2 quads, 2 bikes, 3 tandem trailers, 1 - boat trailer, 4 - 3/4 ton trucks, a Jeep and my mom's car. ALL THE SAME RESULT (only for the last 10 years anyway). If you are adding at a service station to a tire that's 1/2 full or you don't purge, your really not running nitrogen are you? I don't that much time to be chasing around with air compressors and checking tires all the time. That was my reason for starting on nitrogen in the first place. Another point, I've never had a blowout on a trailer tire since I switched. If cost is an issue, I'm not sure how much you are paying, but in Canada it's not much.