I realized that many people might not even really know the proper way to check their Tires Pressure.
Check what the correct Tire Pressure is for your car, and ignore what it says on the Tires sidewall. Those tolerances are usually the Maximum for what the Tires will tolerant, and not what the Tires should be inflated to. There should be a sticker with The Correct PSI (Pounds per Square Inch) that will be located inside of the door or on or around the doojamb.
- Touch your Tires with the back of you hand to see if they are hot. If you've been driving obviously they will be, which most likely will give you an incorrect PSI reading. Wait, a few minutes to let the Tires cool off. It's always good to check cold tires.
- Use a Tire Gauge, and check to see if you Tires are inflated properly. Make sure to push the Tire Gauge as straight as possible onto the Valve Stem. Make sure to check the Tires Pressure at least 3 times! Many times you will check once, but many factors could affect your readings. You will get an inaccurate reading by not pushing in on the Valve Stem straight or correctly, and get a PSI reading that is wrong.
- If you've determined the PSI in your Tires are too low, get out your Portable Air Compressor and pump your tires up. Many Portable Air Compressors are have a Gauge right on them, but many tend to be inaccurate. I'd suggested checking again with a Tire Gauge.
If you don't have a Tire Gauge, I recommend you go buy one at your local Auto Parts Store. Pencil Gauges are only $1 are work fine for most people. However, Pencil Gauges break quickly, and then can give bad readings. Dial Gauges are around $5, but are more accurate and last longer.
Again, Don't Check Hot Tires! Think back to your 6th grade Science class. Remember what the pictures of heated molecules looked like. They were bouncing all over the place! The same thing happens to your Tires if you've been driving for a long time. The air gets hot inside, bouncing around all the air. If you check Hot Tires you will get inaccurate readings! It's best to Check Tires Pressure in the morning when you haven't driven on them. If you don't think this makes a difference… it does! I've done tests myself.
I hope this helps you keep your Tires inflated properly!