What is the tire pressure for a spare tire?
3 Answers
The air pressure of the spare tire should be between 2.3bar and 2.5bar. During driving, if the tire pressure is too high or too low, or if encountering sharp objects, the car tire may experience a blowout. Hazards of low tire pressure: Increased friction coefficient with the road surface, leading to higher fuel consumption; Causes the steering wheel to become heavy and prone to deviation, which are factors detrimental to driving safety; Increases the movement of various parts of the tire, causing abnormal heating due to excessive rolling; Reduces the functionality of the cord and rubber, leading to delamination or cord breakage, and excessive friction with the rim causing damage and abnormal wear at the bead area; Multiplies the friction between the tire and the ground, sharply raising the 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 side prone to cracks, while generating flexing motion, leading to excessive heat, accelerating rubber aging, cord fatigue, and breakage, and enlarging the tire's contact area with the ground, accelerating shoulder wear. Hazards of high tire pressure: Reduces the tire's friction and adhesion, affecting braking performance; Causes steering wheel vibration and deviation, reducing driving comfort; Accelerates wear on the central tread pattern of the tire, shortening its lifespan; Increases vehicle body vibration, indirectly affecting the lifespan of other components; Overextends the tire cords, reducing the tire body's 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 drive quite a lot and have changed spare tires a few times. The tire pressure of a spare tire should never be underestimated. Generally, the spare tire pressure for most vehicles ranges between 45 to 60 pounds per square inch (PSI), which is significantly higher than that of regular tires, mainly for temporary emergency use. My car's spare tire is marked at 55 PSI, as indicated on the label inside the door frame. The last time I had a flat tire on the highway, if it weren't for the sufficient tire pressure, the car would have shaken badly. Don’t think it's simple—you need to check it regularly, at least every six months, because spare tires can lose air over time. If the tire pressure is too low, it might become unstable when used, causing more trouble. It’s best to refer to the vehicle manual to confirm the specific value, as there might be differences between new and old cars. If you don’t have the manual, take it to a repair shop to measure the pressure with a tire gauge—don’t wait until an emergency to scramble. Remember, the spare tire is for emergencies only; after changing it, get the regular tire fixed as soon as possible.
As someone who frequently takes long trips with my family, I pay special attention to driving safety, and spare tire pressure is a key factor. Most vehicles have spare tires set to a pressure range of 45 to 60 psi, designed for temporary heavy loads. Too low pressure can lead to handling difficulties or even accidents. My SUV's spare tire requires 60 psi, clearly stated in the manual—don't guess based on feeling; the tire pressure label on the door might also indicate it. Make it a habit to check the tire pressure before long trips using a portable gauge. A spare tire isn't meant for permanent use; it ages after five years, and no amount of pressure can compensate. Additionally, on highways, spare tires are speed-limited to under 80 km/h—insufficient pressure is dangerous, so replace it with a regular tire promptly. Regular maintenance ensures peace of mind—don't risk big losses over small neglects.
