Air pressure decreases naturally
Tire air pressure decreases naturally (little by little). It is generally accepted that air pressure in tires on a passenger car decreases by 5–10% (10–20kPa) every month.
Impact of low air pressure on fuel consumption
According to material released by The Energy Conservation Center, Japan, fuel consumption increases by around 2% in urban zones and 4% in the suburbs when air pressure drops 50kPa (0.5kgf/cm2) below the appropriate level. Please check air pressure once a month to ensure environmentally friendly and safe driving. Adequately managing air pressure is important not only to maximize the features of the tire but also to avoid an increase in fuel consumption.
If the tire pressure is only 155kPa (1.55bar, 22.5psi), 30% lower than the specified pressure of 220kPa (2.2bar, 31.9psi)...
If the proper inflation pressure is not applied, abnormal wear, as shown below, may occur. In the worst case, the tire could burst due to under-inflation.
Shoulder Wear Center Wear
If the inflation pressure is too If the inflation pressure is too
low, it causes excessive wear high, it causes excessive wear
on both sides of tread. on the center part of tread.