Hah, I use more nitrogen than you do Jim! So there; pttthhhhhhhhhhhhhh. I've got 78.08% as measured from the troposphere. But damn that's a long straw to suck through to get it down from there. Nationwide is the contractor for my roadside assistance though. They are (generally) closer.
I run nitrogen in mine. 78%
Living at sea level, I have more nitrogen in my tires than either one of you. So there. 78.084% by my calculations. Sea level rules when it comes to nitrogen.
I have found nitrogen to be especially beneficial at speeds approaching 180-190 mph, much less beneficial the slower you go than 180. Just my 2 1/2 cents worth.
"Consumer Reports tested one claim: that nitrogen-filled tires keep their pressure longer.
"The test started on Sept. 20, 2006 and the final measurements were taken on Sept. 20, 2007. The results show nitrogen does reduce pressure loss over time, but the reduction is only a 1.3 pounds per square inch difference from air-filled tires... More important, all tires lost air pressure ... Bottom line: Overall, consumers might enjoy the slight improvement in air retention, but it's not a substitute for regular inflation checks."
and
"We use nitrogen because it's a cleaner air; there's no moisture in it," said crew chief Tommy Baldwin on Nascar.com. "Moisture builds heat, and when you use compressed air, there's a lot of water in the airlines and air systems, and when that water gets into the tire, it will expand the tire and puts heat into it, and will eventually cause a tire problem."
One thing I noticed while reading about this subject, companies that sell nitrogen for tires claim all sorts of BS, and scientific studies basically disprove their claims (pesky facts). It's sort of like a nitrogen religion - believe it or do not believe it.
So if you check your tires weekly (I do) and ride at less than 180 mph ( I try to keep it under that, usually), nitrogen is basically a cool valve stem & a bill for - air. Car tires./bike tires - not for me. However, I have a riding lawn mower that apparently would benefit greatly from nitrogen in it's tires according to folk lore, but it is a very long ride to the refilling station.....