Tire Question as this is My first "winter" (getting colder here in NJ but not quite winter yet) with my Tesla MYP. After the car was sitting in my driveway for several days as the weather got colder, I got a tire pressure warning light on my display when I first got back in the car. It was showing the pressure was about 37/38 psi in each tire and it should be 42. I went to the local service station and filled the tires up to 42. No issues since. Is this normal during the colder weather? Was it because I hadn't used the car for several days? Any winter tips to maintain proper tire pressure? Thanks.
It is normal for tire pressure to change with the change in ambient air temperature. Expect to lose 1 to 2 PSI of tire pressure for every 10 degree drop in outside air temperature. Always check tire pressure after the vehicle has not been driven for at least several hours, not parked in direct sun. (Tip: Add an extra 2 to 3 PSI now so was the temperature continues to fall you don't have to add more air to the tires. 42 PSI is the recommended pressure. There is no issue if the tire is inflated a few pounds lower or higher for comfort or due to anticipated temperature change.)
In the spring, as the outside temperature rises you will want to bleed off some of the air in the tire (1 to 2 PSI) to account for the tire pressure increase as it gets warmer.
Invest in a good tire pressure gauge that is accurate to within +/- 1 PSI. I prefer using an analog gauge but there are also digital tire pressure gauges. (Also purchase a tire tread depth gauge that reads in 32nds of an inch as these are under $10. The tread depth gauge will help you determine when to rotate the tires or if the tires are wearing unevenly (inner, center, outer tread) as excessive/uneven tire wear indicates that the vehicle requires a 4 wheel alignment.)
The Tesla Tire Pressure Monitoring System (TPMS) sensors will go to sleep when the Tesla vehicle is stopped, parked to conserve the TPMS sensor battery. You need to drive a short distance before the TPMS will provide an updated readout. (In my experience the Tesla TPMS is accurate to within 1 PSI but does not always provide exactly the same readout for all four tires at a given time (the difference when starting to drive is always within 1 PSI of the other tire or tires (verified set to the same pressure with my tire pressure gauge.) This may be due to interference in the TMPS receiver.
After being driven warm tires can read 4 or 5 PSI above the cold tire pressure. This is normal. Also, the front tires may read higher by a few PSI than the rear tires when the tires are warm. This is why it is important to check, set tire pressure when vehicle has been stationary, not after being driven more than approx. 1/2 mile and not when parked in direct sun. (Early in the A.M. is a good time to check, set the tire pressure.)
If the Tesla TPMS displays one tire as being lower than the other tires (by more than 1 to 2 PSI) when you have recently set all tires to the same tire pressure then suspect leak in the tire. (The most likely source of the air leak will be a puncture but could also be caused by dirt in the tire valve stem or a bad seal where the tire bead seats on the wheel. A tire shop should be able to quickly identify the source of the leak.)
There are many battery powered and 12V powered tire inflators available to help you keep your tires properly inflated without having to drive to a service station. (WaWa locations that sell gas also have air hoses for inflating tires.)
