Why Does Tire Pressure Need to Be Checked?
Your vehicle's tires are, quite literally, where the rubber meets the road. Modern tires have traction and wear characteristics that were unimaginable 40 years ago, but they do still lose air pressure with time. Also, for every 10 degrees the temperature drops, your tire pressure goes down 1 psi just because the air contracts as it cools.
Properly inflated tires make your car or truck handle better, plus you get better fuel economy and less tire wear; you save money two different ways! Older tires, with tall (75 or even 80 series), softer sidewalls showed a loss of 5 psi pretty obviously, but in a modern stiff low profile rubber it can be hard to spot one that is down even 10 psi.