Recently you noticed the tire pressure on your car was low. Perhaps the warning indicator light went on to draw your attention to it. You went around the vehicle, but didn’t notice any ‘flat tires.’ You assumed it was a mistake, but when you finally got around to bring your BMW to an air pump and added some air, you realized it was down four PSI in most of the tires.
Does that mean the tires are bad?
No, it doesn’t. There could be many factors for low tire pressure that have nothing to do with a leak in the tire itself. The most common issue happens when the seasons begin to change.
When the temperature begins to fluctuate and colder temperatures are rolling in, it can affect tire pressure. The cold air changes the speed at which the molecules inside the tire begin moving. When the temperature warms up, the road surface heats up, and the tire gets hotter, those molecules begin speeding up once again. When this happens over and over again, some pressure loss will occur.
What is this a sign of?
It’s a sign that you need to begin paying attention to your tires. Winter is just around the corner and that means it’s time to consider replacing the tires with good, solid winter tires, or making sure the all season tires you have already on your vehicle are inflated to proper pressure.
If you have low pressure in your tires, on a warmer, hotter day, it may improve traction on dry surface, but it will reduce traction on wet surfaces. In colder air, that lower pressure is going to create a slicker surface between the tire and road, meaning you might lose control more easily than if you had them inflated properly, possibly even over inflating them just a bit.
An experienced technician at an authorized BMW service center can help you better understand optimal tire pressure for your particular BMW.