What is the recommended tire pressure for 5 Series run-flat tires?
2 Answers
5 Series run-flat tires should be inflated to 2.4-2.5bar. The tire pressure for run-flat tires is the same as that for regular tires. According to the international GBT2978-2008 standard, the recommended tire pressures for different types of tires are as follows: Standard tires: 2.4-2.5bar; Reinforced tires: 2.8-2.9bar; Maximum pressure: should not exceed 3.5bar. Hazards of over-inflation: Reduced tire friction and adhesion, affecting braking performance; Causes steering wheel vibration and deviation, reducing driving comfort; Accelerates wear on the central tread pattern, shortening tire lifespan; Increases vehicle vibration, indirectly affecting the lifespan of other components; Overextends tire cords, reducing tire elasticity and increasing the load on the vehicle during driving; Decreases puncture resistance. When encountering sharp objects like nails or glass on the road, the tire is more prone to punctures, and impacts can cause internal cracks or blowouts, leading to tire failure.
I usually commute in my BMW 5 Series, and the run-flat tires are indeed worry-free, but tire pressure can't be taken lightly. The recommended tire pressure for my car is clearly stated on the driver's door pillar label: front tires are generally 2.5 to 2.6 bar (about 36 to 38 PSI), and rear tires are 2.7 to 2.8 bar (about 39 to 40 PSI). Checking when the car is cold gives the most accurate reading—don't measure right after driving. I make it a habit to check once a month, adding a bit more pressure in winter (cold contraction) and avoiding overinflation in summer (risk of heat expansion). Low tire pressure makes steering heavy and fuel consumption skyrocket, while overinflation makes tires stiff and prone to blowouts. Keep a portable tire pressure gauge in the glove box for quick checks to prevent surprises. Don’t forget to inflate the spare tire fully—run-flat tires can limp for a short distance when low on air, but don’t rely on them for too long. These tips have helped me go five years without needing new tires.
