What is the tire pressure for all four wheels of the BMW 730Li?
2 Answers
Under normal circumstances, the standard factory tire pressure for all four wheels of the BMW 730Li is 2.3bar to 2.5bar when the car is cold. The maximum should not exceed 3.0bar, and the minimum should not be lower than 2.1bar. A slightly higher pressure is acceptable, but low pressure is very dangerous. Hazards of low tire pressure: Increased friction coefficient with the road surface, leading to higher fuel consumption; Causes heavy steering and tendencies to veer, among other factors detrimental to driving safety; Increases the movement of various parts of the tire, leading to abnormal heating due to excessive rolling; Reduces the functionality of the cords and rubber, causing delamination or cord breakage, and excessive friction with the rim, leading to damage and abnormal wear at the bead area; Multiplies the friction between the tire and the ground, causing a sharp rise in tire temperature, softening the tire, and drastically reducing its strength. High-speed driving may result in a blowout; Increases tire body deformation, making the tire sidewalls prone to cracking, while generating flexing motion, leading to excessive heat, accelerating rubber aging, cord fatigue, and breakage, and increasing the tire's contact area, accelerating shoulder wear. Hazards of high tire pressure: Reduces 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; Increases vehicle vibration, indirectly affecting the lifespan of other components; Overextends the tire cords, reducing tire elasticity and increasing the load on the car during driving; Decreases puncture resistance. When encountering sharp objects like nails or glass on the road, they can easily penetrate the tire, causing internal cracks and blowouts due to impact.
I remember my BMW 730Li had small stickers on the door edges indicating the standard tire pressure was approximately 2.2 bar or 32 psi for the front wheels and 2.4 bar or 35 psi for the rear wheels. This data came from the owner's manual, and I've personally verified it. During long-distance driving, tire pressure fluctuates significantly – for instance, in summer heat, the pressure can increase by over 0.2 bar, requiring me to periodically release some air to prevent accelerated tire wear and increased fuel consumption. In winter, I need to add some air to ensure comfort, especially when carrying family members and luggage. Thanks to this habit, my car has never experienced a flat tire. Checking is simple – just buy a portable tire pressure gauge.
