Vehicle shown in this step: 2019 BMW 430i xDrive Gran Coupe 2.0L 4 Cyl. Turbo
Procedure notes
Did you know that the most important thing you can do to care for your tires and improve your fuel economy is to maintain the proper air pressure? Checking the tire pressure in your 2018 BMW 440i xDrive is relatively easy and important to do on a regular basis. Open the driver side door on your 440i xDrive and look for a sticker that indicates what the tire pressure should be. Don't use the maximum pressure indicated on the sidewall of your tires. It is best to check the tire pressure on your 440i xDrive in the morning before the car has been used or when you have driven it for less than a mile. When you drive your 440i xDrive, the air inside your tires warms up and expands, so to get an accurate reading, check the tire pressure when the car has not been driven recently.
Many vehicles are equipped with a TPMS sensor in each wheel to detect the tire pressure of each tire. TPMS means tire pressure monitoring system. If your 2018 BMW 440i xDrive has a tire pressure light that illuminates in the dashboard when you start your vehicle, it has TPMS sensors. The TPMS light should illuminate briefly when you start your car, but then turn off afterwards. If your tire pressure light keeps coming on or the tire pressure light is blinking or flashing, then you likely have low tire pressure in your tires. For most vehicles, inflate the tires to the proper pressure and drive your vehicle a few miles and the tire pressure light will reset and turn off. TPMS sensors have batteries in them and they are mounted inside of the tire. Eventually that battery will die and the tire pressure sensor will need to be replaced in order to get the BMW 440i xDrive tire pressure light off.
Underinflated tires decrease the gas mileage of your 440i xDrive, wear out faster and make the vehicle harder to steer, whereas overinflated tires blow out more easily, wear out faster and can cause unsafe handling dynamics. For these reasons and more – keeping your tires properly inflated on a regular basis is easy and important.
查看中文对照 · Chinese translation
你知道，你为轮胎保养和提升燃油经济性所能做的最重要的事情就是保持正确的胎压。 定期检查你的 2018 宝马 440i xDrive 的轮胎气压相对容易，也非常重要。 在您的 440i xDrive 车辆的驾驶员侧车门上打开，查找标明轮胎压力应为多少的标签。 不要使用轮胎胎壁上标注的最大压力。 最好在早晨、车辆未使用或行驶里程少于一英里时，检查您的 440i xDrive 的胎压。 当你驾驶你的 440i xDrive 时，轮胎内的空气会变热并膨胀，因此为了获得准确的读数，请在车辆未行驶后检查胎压。
许多车辆在每个车轮都配备了TPMS传感器，用于检测每个轮胎的胎压。 TPMS 指胎压监测系统。 如果您的 2018 宝马 440i xDrive 车辆在启动时仪表盘上出现胎压警示灯，说明该车配备了 TPMS 传感器。 启动车辆时，胎压监测系统（TPMS）灯应短暂亮起，之后熄灭。 如果您的胎压警示灯持续亮起或闪烁，那么您的轮胎很可能存在胎压过低的情况。 对于大多数车辆，将轮胎充至正确的气压，并驾驶车辆几英里，胎压警示灯就会自动复位并熄灭。 胎压监测传感器内部有电池，安装在轮胎内部。 最终电池会耗尽，需要更换胎压传感器才能熄灭宝马 440i xDrive的胎压警示灯。
胎压不足会降低440i xDrive的燃油经济性，导致胎面磨损加剧，并使车辆转向更困难；而胎压过高则容易爆胎，磨损更快，还可能引发不安全的操控性能。 因此以及更多原因——定期保持轮胎正确充气是简单且重要的。