Fill Tires With NitrogenOr 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. Check out these tips on how to buy tires, too.