Hi Gang, Cool idea? ... or scam? http://www.tirelast.com/id15.html I was up in Ohio recently ... and my dad pointed out the spiffy green valve stem covers on the tires of his car ... Not immediately understanding their socially responsible significance, I merely commented on the questionable fashionability of installing light green valve stem covers on his navy blue car. (After all, it's not like he put Sprewells on the thing!) I am then informed that the light green covers indicate that the tires have been filled with nitrogen!! ... Whoa! Get back! Nitrogen? Vaguely remembering from some high school science class (taken, no doubt, in an un-named Pre-Cambrian era) that normal air is, what, 80%(?) nitrogen anyway ... I fail to be particularly impressed. As scams go (if, indeed, this *is* a scam - and I'm not saying it is - yet) this one seems fairly innocuous to me ... as it's not all that expensive. So ... is this good stuff ... or is this a crock? 'Tirelessly' inquiring, RonL.