Some see TPMS (tire pressure monitoring system) as yet another “idiot light” to get drivers to pay more attention to their cars, there’s a very good reason for that little TPMS warning light to come on. To put it bluntly, it’s because most drivers simply aren’t paying attention to tire pressure, which can lead to several problems, all of them expensive and some of them downright scary:

• At worst, low tire pressure could lead to a blowout and a loss of control, so basically low tire pressure can kill you or someone else.
• Underinflated tires to grip the road the same, and a loss of traction in a high-speed curve or in a panic stop could lead to, you get the idea, death.

Still, that’s just the worst-case scenario, but it doesn’t end there:

• Underinflated tires wear out faster, costing people more money to replace tires more often. This is great for tire companies, but not-so-great for your wallet.
• Low tire pressure wastes fuel, something on the order of 5 million gallons per day, according to the DOT (Department of Transportation). Low tire pressure and reduced fuel economy is costing you money in increased refueling costs.
• Poor fuel economy is also putting more carbon dioxide (CO₂) into the atmosphere than necessary, around 49,000 tons of extra CO₂ every day in the United States. The WHO (World Health Organization) suggests climate change might cause an additional 250,000 deaths per year, so low tire pressure, again, is death.

Why Tires “Lose” Air Pressure

Now, we could simply avoid all these problems if we could count on tires just holding their pressure when set at the factory, but no tire holds its pressure.

• First, air naturally escapes rubber tires, either from miniscule leaks or through the rubber itself, and even “perfect” tires generally lose 1 to 2 PSI (pounds per square inch) per month. Imperfectly-sealed tires may lose 1 or 2 PSI per week.
• Then, because gases expand and contract with temperature, tire pressure naturally fluctuates with the weather and use, about 1 PSI per 10 °F change in temperature. On some days, tire pressure might fluctuate up to 5 PSI, simply because of a change in weather and how much highway time you put on them!

Stop Killing Yourself and Get a Tire Pressure Gauge

Obviously, we need to be checking tire pressure a lot more than we are now, otherwise TPMS wouldn’t have been federally-mandated since 2007. Fortunately, checking tire pressure regularly doesn’t cost that much, is super easy to do, and takes just a few minutes a week. Invest in a decent tire pressure gauge – spend more than a dollar – and learn how to use it. Buying a tire inflator is optional, but also a good investment. First, check the Tire and Loading sticker on the driver’s door jamb, where you’ll find suggested tire pressure for your vehicle. Then, when the tires are “cold,” or haven’t been driven for at least three hours, check the tire pressure. If “cold” tire pressure is more than 2 PSI off-specification, inflate or deflate them to specification. It’s good practice to do this at least once a month, but more often may be necessary, depending on the state of your tires and how much the weather is changing.