Pure nitrogen pump tires have better stability than air-pumped tires, although the price is high and quite inconvenient.
Most cars pump air tires, containing 76% nitrogen, 21% oxygen and 3% other gases. However, now many stores offer new services, pumping tires with nitrogen of 92-98% purity.
Nitrogen has been used extensively on race cars, large trucks and airplanes. The advantage of this method is tire pressure stability. Because the nitrogen molecule is larger than oxygen, the diffusion rate is slower than the rubber membrane. With the same pressure drop, a nitrogen pump takes up to 3 months while air tires are only 1 month.
Another advantage is that pure nitrogen does not contain water vapor so it is less expandable because of heat. While the air contains a certain amount of moisture, the tire expands faster, resulting in lower operating stability. This is why most racing cars use nitrogen because the tire temperature increases very fast when operating at high speeds and continuous braking.
In addition, because it does not contain oxygen, it is necessary to pump tires with nitrogen to avoid oxidation and explosion.
The above advantages of nitrogen tires are undisputed. However, whether it really helps to save fuel is still a big question . In a 2006 paper, the AP once cited the engineer George Bourque, working at Fairfield, said he traveled 0.4 km to 0.6 km per liter of fuel with nitrogen-based tires.
Prestigious organizations do not make any conclusions. The US Energy Department said that only the right tire pressure was needed, regardless of air or nitrogen, the car was still capable of saving 3.3% of fuel.
Rae Tyson, spokesman for the US National Traffic Safety Authority, NHTSA, does not express views on nitrogen use. However, he said that this method " encourages " the driver to keep the tire pressure, thereby reducing fuel consumption and increasing safety.
Whether pumped with nitrogen or air, keeping the tire pressure properly can save up to 3.3% of fuel.(Photo: AP)
Consumers Union experts, Consumer Reports magazine's reputation, does not support any method of gas savings. " Nitrogen is certainly safer and theoretically, this leads to other benefits, " said Douglas Love, a Consumers Union spokesman.
Besides these advantages, pumping tires with nitrogen has disadvantages such as high cost. The cost for each tire in Vietnam is about 10,000 - 15,000 VND and in Canada is 8 USD. This amount is not included with the following pumping times. If the tire is small, the driver must find a station with specialized pumping equipment. In case of force majeure is air pump, tire will lose all advantages that nitrogen brings.
With the above analysis, it is clear that nitrogen pump is effective but not really necessary. If you want to save fuel and safety when driving, you just need to check regularly and keep the tire pressure properly.