One of the things that takes little time but helps your car a lot is checking the tire pressure. Incorrect tire pressure not only causes tire damage but has a direct consequence on your safety and stability on the road. Here's the procedure :

1. The first thing you need to do,to make a proper check is to preferably put your car on a horizontal surface (not on a uphill, downhill etc.)

2. You need a tire pressure gage (digital or analogue). If you don't have one in your car equipment, buy one. Even the most fancy ones don't cost a lot and you can buy them almost everywhere.

3. Take off the cap on the air valve (put it in sight, you can loose it easily)

4. Put the gage on the valve and press. The gage will instantly tell you the tire pressure.

5. Look at the markings on the tire or the plate that's by the driver door. On them are the correct values for the pressure on your tires.

6. Inflate or deflate the tire to the correct pressur

 

If you're referring to car tires, most of them should be inflated to about 35 psi. Same for light duty truck tires for street use. Temperature will affect tire pressure. Colder temps cause pressure to go down, warmer temps cause it to go up slightly. Also, make sure the tires are cold when you check air pressure. Driving for a few miles and then checking tire pressure will result in slightly higher readings.

 

Some people seem to think the max pressure stamped into the tire is what you're supposed to run. The sticker on the driver's door edge is what you should always go by. My truck takes 35 psi front and rear but my old truck took 40 in the front. If you go to a quick oil change place they will sometimes pump them up to the wrong pressure so you have to check for that.