I want to add to this information, it is very good that we all know what pressure our tires should have at all time and especially while traveling and that we stick to the recommended pressure. It is also very important to know that more Vulcanizer have gauges that read wrongly or they themselves read them wrongly. Also it is recommended by practice that we calibrate any equipment or instrument used for measurement once every 6 months at most every year and from my findings, no Nigerian road side vulcanizer does that and most of the have gauges does not begin from Zero( no zero calibration) for accurate readings.
I recommend that every car own should endeavor to have personal gauges that you can use to double and confirm what the road side vulcanizer has applied to your tires and that the Federal road safety corps should as a matter of urgency run a sentisation programme on the need for gauge calibration and standardization conformity to Vulcanizers and the pupil.