While newer Ford Focus models feature their own tire-pressure-monitoring systems, you may come across situations in which the monitoring system is malfunctioning, the circuitry is having issues or the alarm may go off for large pressure fluctuations due to prolonged exposure to extreme temperatures. In these situations, you should have your own pressure gauge and know how to use it.
Purchase your own tire gauge. While there are air meters available at service stations, they may be inaccurate due to extensive use. So it's better to have your own. They are available at auto supply stores and many retailers.
Check that you can read the gauge easily. Digital gauges are the easiest to read, but they will definitely cost more. For a regular gauge, make sure you can make out the scale easily, as you will be reading it repeatedly throughout the process.
Familiarize yourself with your tire. Locate your vehicle's certification label and tire information placards, if your tires are the original ones. You can find this information in your owner's manual or permanently attached to the vehicle door edge or door post. Keep in mind that the recommended pressure is for a cold tire, meaning that it has not been driven for about 3 hours. Ford recommends the pressure in tires of the Ford Focus be kept at 26 to 34 psi.
Take the pressure measurement for each tire. Remove the cap on the valve, and then press your gauge firmly against the valve opening. If you hear a hissing sound, it means air is leaking out and you will need to press more firmly. Take the reading and compare it with the information you obtained on that tire.
Adjust the pressure, if necessary. To lower the pressure, press the gauge edge gently against the valve. Measure frequently in the process to make sure the tire does not deflate too much. Screw the cap back on when you are done. To increase the pressure, you need to get your car to a service station and use an air pump or use a home air compressor.
