Tyres are the only contact between your vehicle and the road. Inflation pressure is an extremely important factor affecting safety driving performances, mileage and fuel consumption. Both under-inflation and over-inflation can negatively affect your tyre performance level: it is therefore important to always maintain the correct pressure on your vehicle.
Properly checking tyre pressure requires an accurate air gauge. Many people believe that they can check air pressure just by looking at the tyre and judging the sidewall appearance. Also, many people use the air meters at petrol stations, which can be grossly inaccurate due to exposure or abuse. Invest in a quality air gauge. For trucks and RVs, use a dual-head inflation gauge that is calibrated up to 120 psi at 2 psi increments.