My father in law filled his Altima's tires with nitrogen at Costco and they seem to leak as much as before. He must have some other kind of problem. Meanwhile I have been using regular air in my tires for years and I check the pressure regularly and I rarely have to adjust it. I would think that air pressure problems in tires would be much more likely to occur for other reasons than those pesky little air molecules escaping through the sidewall. And think about it, at $3-$5 a tire it wouldn't take much to spend as much on that as it would cost to pick up a copy of "The Simple Life" on DVD (also available at Costco).

__________________
Jason Priest
1999 E430
1995 E420 - retired
1986 420SEL - retired