Nitrogen & You!

You may have green caps on your valve stems. More and more frequently new cars are rolling off the lot with Nitrogen in their tires. Some tire shops offer it, so what does it do? Well the theory goes that the Nitrogen molecules are ever so slightly larger than those of the oxygen in air, so they won't escape through the rubber as quickly and easily as air. The marketing also suggests that the tire pressure will be more stable throughout temperature ranges. Not only does this mean ambient temperatures, tires heat up significantly under heavy strain. Aircraft undergo extreme cold and loads and use Nitrogen. Nascar uses Nitrogen in their tires, where temps can exceed 90 degrees C. Maintaining tire pressures at these temperature extremes is integral to the success and safety of all involved. Maybe your car doesn't see such stresses, but theoretically a maintained tire pressure will improve fuel mileage over the long haul. The added benefit that some marketing references is a reduction of oxidation of the tire inner liner. This could also ring true on untreated surfaces of wheels within the tire, and on TPMS components which may be sensitive to oxidation. Is it worth it? If the benefits are of value to you, then perhaps.