Keeping the correct air pressure in your tires is as important as giving your engine a tune-up. The economic benefits are perhaps even greater. With the right amount of air pressure, your tires wear longer, save fuel, enhance handling, and prevent accidents. If you consider the liabilities of not maintaining the correct air pressure—poor gas mileage, loss of tire life, bad handling (perhaps even loss of control), and potential vehicle overloading—then the need to routinely add air to your tires will become clearer.
Gas prices are something we can’t control. But we can control how efficiently our vehicle is using fuel. You are riding on one of the best ways to do that—keeping your tires properly inflated. Keeping your tires properly inflated may result in up to 10% better fuel efficiency.
Routine Air Pressure Checks
Perhaps because our tires do so much without seeming to need any attention, we tend to overlook this important task. But tires do lose pressure, slowly but surely, every day, through the process of permeation. Generally, a tire will lose one or two pounds of air per month in cool weather and even more in warmer weather. Also, tires are subjected to flexing and impacts that can diminish air pressure.
So, think in terms of refilling your tire just like you do your gas tank. Actually, that’s a good reminder—refill your tires every other time you fill up. That’s the recommended interval. Another time to check air pressure is when your tires are rotated. Many vehicles have different tire pressures on the front and rear axle, so remember to have this adjustment made.
Air Pressure Information
The correct air pressure may be found in the owner’s manual or on the tire placard. The placard tells you the maximum vehicle load, the cold tire pressures, and the tire size recommended by the vehicle manufacturer.
Another valuable resource is the Tire Load/Inflation Tables. Not only will this document tell you the correct tire pressure for stock sizes, but it will provide information on optional plus sizes as well.
Other Air Pressure Factors
Besides routine air pressure checks, other circumstances necessitate a visit to the air pump. Seasonal changes or altitude changes create a rise or drop in air pressure (for every 10 degrees change in temperature, tire pressure changes 1 PSI). But perhaps the most overlooked factor is truck loading. Since vehicles can be configured and loaded in many ways, the proper inflation pressure should be determined by actual tire loads. This is best determined by weighing the vehicle as vehicle loading can change from trip to trip.
How can routine air pressure maintenance impact our environment? Consider that fewer tires per year would end up in the landfills and scrap heaps that trouble our ecology. How many tires are we talking about? We estimate that most drivers lose from 10% to as much as 50% of tire tread life due to under-inflation. That’s a significant statistic. Now consider the extra fuel we burn to push vehicles along on soft, under-inflated tires. While the statistics vary widely and inconclusively, the implications are staggering.
Maintaining tire pressure is a small line item in our busy daily routines, but it adds up to big environmental consequences. We must all care and take action to do the right thing.
Nitrogen in Truck Tires
There is a lot of talk about putting nitrogen in truck tires. Is this good or bad?
Nitrogen is an inert gas with large molecules and in theory it should have less osmosis through the tire casing as compared to air. STTC's tests show no significant advantage of using nitrogen over air in our commercial radial truck tires. That’s because our casing construction features chlorobutyl inner liners which do a great job of trapping air. In a lesser-brand tire with less advanced inner liners, nitrogen may help tires retain their inflation levels.