Should You Read the Inner or Outer Scale on a Tire Pressure Gauge?

[LaJohnny]

Tire pressure gauges can display readings on both the inner and outer scales, but the units of measurement differ between them. The inner scale uses bar as its unit, while the outer scale uses kPa or psi. According to the international standard GBT2978-2008, the recommended tire pressures for different types of tires are as follows: Standard tires: 2.4-2.5 bar; Reinforced tires: 2.8-2.9 bar; Maximum pressure: should not exceed 3.5 bar. Hazards of overinflated tires: Reduced tire friction and adhesion, affecting braking performance; Causes steering wheel vibration and veering, reducing driving comfort; Accelerates wear on the central tread pattern, shortening tire lifespan. Hazards of underinflated tires: Increases friction coefficient with the road surface, leading to higher fuel consumption; Creates heavy steering and veering tendencies, compromising driving safety; Increases movement in various parts of the tire, causing abnormal heat buildup due to excessive compression.