Fill Tires With Nitrogen—Or Not?
Some dealers now offer to fill tires with nitrogen instead of regular air for an additional charge. Nitrogen
leaks less than compressed atmospheric
air (because nitrogen molecules
are larger than oxygen molecules)
and reduces rubber oxidation.
But that doesn't mean nitrogen
never leaks. The problem is
that once you commit to a nitrogen
fill, you must stick with it for the
life of the tire. The instant you add
compressed air, you negate all the
benefits.
Since you still need to check and
refill your tires, and since nitrogen
is hard to find, you'll be married to
the dealer forever. That's good if
they offer free coffee and doughnuts
while you wait, but bad if
they're not conveniently located.
Even though nitrogen really is
better than regular old air, it's
doubtful you'll ever see enough of
a benefit to justify the
investment. Your tires will probably
wear out from normal driving
long before the important benefits
of nitrogen really kick in. But if
you drive less than 5,000 miles per
year and plan to keep your tires for
10 years (and don't mind hanging
out at the dealer), nitrogen is definitely
worth it. By the way, the
green caps on tire valve stems indicate
the tire is filled with nitrogen.
