Getting tyres filled with nitrogen is the latest automotive fad. Vendors of nitrogen are promising longer tyre life, less frequent refilling, lower fuel consumption and more comfort. They also point to aircraft and racing cars which use nitrogen in their tyres. Lured by these claims, thousands of automobile owners are getting their tyres inflated with nitrogen for Rs 25-60 per tyre. But are these claims really true?
When one checks expert opinion (here and here ), it appears that these claims are either not true or misleading.
Using nitrogen gives longer life to tyres in principle because nitrogen does not corrode rubber, but tyres would be worn out before this benefit can be realized. Nitrogen also requires less refilling, but if the cost of nitrogen is factored in, this is not a big advantage. If tyre pressure is maintained at the recommended pressure, nitrogen does not reduce fuel consumption or give a more comfortable ride. The reference to aircraft and racing cars is misleading. Modern aircraft fly at about 30000 feet where the surrounding temperature can be as low as -60 degrees. If aircraft tyres are filled with air, the moisture and carbon dioxide in the air freeze at these low temperatures and this will greatly decrease the tyre pressure. The reduction in the tyre pressure due to freezing of moisture and carbon dioxide and ice chunks rolling around in the tyres are dangerous when the planes land. Cars running on streets do not have this problem and so nitrogen offers no benefit. Similarly, race car tyres have to be filled in in the shortest possible time and this can be better done with nitrogen stored in high pressure cylinders than with pumping air with mechanical pumps. Ordinary cars again do not have this problem.
The three largest tyre companies in the world, Michelin, Bridgestone and Goodyear support the use of nitrogen in tyres only because nitrogen-filled tyres retain pressure for longer periods. They do not claim any other benefits from nitrogen filling. As said earlier, if the cost of nitrogen is factored in, this is not a big advantage.
In the US, nitrogen filling is a tremendously profitable business taking into consideration the low cost of equipment and nitrogen compared to the cost at which nitrogen filling is done. So many experts feel that promotion of nitrogen is just a marketing gimmick.
Automobile users are advised to look carefully at arguments on both sides of the issue before going regularly for nitrogen filling.
P.M. Bhat, Mysore Grahakara Parishat