Once you know how much air you need, the next step is to make sure you fill those tires up correctly. If you have to drive a distance to get air, check and record the tire pressure first and add the appropriate air pressure when you get to the pump. It is normal for tires to heat up and the air pressure inside to go up as you drive. If you overfill the tire, release air by pushing on the metal stem in the center of the valve with a fingernail or the tip of a pen. Then recheck the pressure with your tire gauge.
Some spare tires require higher inflation pressure.
Visually inspect the tires to make sure there are no nails or other objects embedded that could poke a hole in the tire and cause an air leak. Check the sidewalls to make sure there are no gouges, cuts, bulges or other irregularities. It turns out, the FTC says, that motor oil treated with zMax produced more than twice as much bearing corrosion than motor oil alone. This is the latest in a series of crackdowns on unsubstantiated claims made by major brands of engine treatment products. In this case, the agency's lawsuit seeks to halt zMax's advertising and force the company to refund customers money.