I have been running my Model Y at 38 lbs cold, and it definitely is a touch softer ride . Any opinions on how much I am harming the ultimate life on these tires welcome
The manufacturer's recommended tire pressure (front and rear) is always on a printed label on the B pillar next to the driver's door. For the Tesla Model Y that is 42 PSI (cold).
Under inflated tires will run hotter; under inflation is the leading cause of tire failure.
Tesla specifies Extra Load (XL) rated tires for the Model Y. XL tires require 41 to 42 PSI to meet their rated load.
When you lower (or raise) the cold measured tire pressure by 1 or 2 PSI from the recommended pressure then there should be no issue.
When tires are under inflated the tires can wear faster on the edges than in the center. When tires are over inflated the converse can happen, the center of the tread area can wear faster than the edges.
The reason that all new vehicles come with a tire pressure monitor system (TPMS) is that there were too many accidents where gross under inflation of one or more tires was a direct cause or a contributing cause in roll over collisions and other fatal accidents.
Tesla provides clear information on proper tire maintenance on page 166 of the Tesla Model Y Owner's Manual:
https://www.tesla.com/sites/default/files/model_y_owners_manual_north_america_en.pdf
WARNING!
Under-inflation is the most common cause of tire failures and can cause a tire to overheat, resulting in severe tire cracking, tread separation, or blowout, which causes unexpected loss of vehicle control and increased risk of injury.
Under-inflation also reduces the vehicle's range and tire tread life.
Check tire pressures using an accurate pressure gauge when tires are cold. It takes only about one mile (1.6 km) of driving to warm up the tires sufficiently to affect tire pressures. Parking the vehicle in direct sunlight or in hot weather can also affect tire pressures. If you must check warm tires, expect increased pressures. Do not let air out of warm tires in an attempt to match recommended cold tire pressures. A hot tire at or below the recommended cold tire inflation pressure is dangerously under-inflated.
As noted by anaconda, under inflation will reduce your driving efficiency and decrease your range. How much range? Perhaps ~ -1% per PSI below the recommended pressure; if you increase your tire pressure you can increase your range by ~+1% for every PSI above the recommended tire pressure.
The maximum tire pressure is printed on the sidewall of the tire. For the OE tires on the Tesla Model Y this is 51 PSI (cold). Tire pressure readings should always be taken when the tires are cold before the vehicle has been driven and not when the tires are outdoors and exposed to the sun. A quality tire pressure gauge should be used, rated for accuracy within +/- 1 PSI.
As we enter fall, keep in mind that tire pressure will drop approximately 1 to 2 PSI for every 10 degree drop in temperature. (I recently checked and inflated the tires on my Model Y to 45 PSI.) I know that in the coming weeks the tire pressure will drop with the temperature to between 42 and 44 PSI which is where I want it to be anyway.
www.michelin.com
teslamotorsclub.com
. In any case, this is what I've had. Me thinks that lowering it to less than 40 will affect tire geometry too much. It is a wider roller.
