Properly inflated tires are one of the best and easiest ways to maintain optimal fuel economy and safety. To check the tire pressure on a Ford Focus, unscrew the valve cap on the tire and connect a tire pressure gauge. Once you push the gauge, it will register the current tire pressure.
Remember that while all tires have a maximum tire pressure indicated on the side, always refer to the tire pressure sticker inside your door jamb for optimal inflation.
If the tire pressure is low, use a compressor or visit a local gas station to inflate your tires to meet the appropriate requirements.