Most late model vehicles have a tire pressure warning indicator lamp. If this lamp is coming on after the vehicle has been sitting overnight or on cold mornings and it goes out after a few miles of driving, then your tires are getting low.
Usually, the low tire pressure lamp will come on if there is a 15% variance in pressure between the tires. Each tire has a tire pressure monitor in it. These sensors operate by battery. Battery life is usually 5 years. A low battery can also cause this lamp to come on.
Influences on tire pressure:
For every 10 degrees of outside temperature change, your tires will gain or lose one pound of pressure. Every month your tires will lose one psi of pressure as the molecular structure of the compressed air permeates through the membrane of the tire itself. Just driving your vehicle will cause tire pressures to raise. Tire pressures should be checked cold (before driving or 3 hours after driving) to get an accurate reading.
A word about Nitrogen in your tires:
Nitrogen does not permeate the membrane nor fluctuate as rapidly as compressed air. It is also a dry gas as opposed to compressed air. Many shops are using nitrogen in efforts to stabilize the pressures. NASCAR, the Military, and NASA have been using it for years. A common misconception is that you cannot mix nitrogen with regular air. This is not true. The only concern with the mixture is that the nitrogen loses its benefits if it is not 95% or purer. It is perfectly safe.
Do not overlook your tire pressures. In addition to costing you fuel economy, it can quickly become a safety issue. Stop by Eagle Buick GMC in Homosassa for more expert vehicle maintenance tips and advice!