You can do it from a settings page on the car display. Older cars had a pushbutton under the steering wheel. You set the pressure properly and then reset the alarm point.
The gen5 has the newer TPMS which is simpler and better than the older style. While you can still set the pressures the old way(inflate the tires to what you want, then tell the car to use that setting), you can also just input the pressure you want to use using the up/down buttons on the steering wheel. You can use that same screen to see what pressure setting they're currently using. Pg. 431 of the HEV manual, and pg. 520 of the PHEV manual.
In past generations the door decal shows two sets of values: higher for the smaller dia wheel and lower for larger dia wheel. With gen 3 it’s 35/33 and 33/32 psi respectively. IIRC…
I just had a guy check my tires in the middle of a mid 80s day with the dash reading of 43 psi. The tires were actually at 40 psi so now I know it’s off by about 3. I had him lower them to 38F/ 36R for now until I figure out the sensor settings. I did this right after reading a post on FB from a local friend who has a Gen 5 LE AWD. She’s a very careful driver and just trashed a tire on a pothole. It’s a PIA needing to wait for two AAA drivers. One to verify the tire can’t be repaired and another to have the car towed. I would say bring a flatbed because I’m not using that gooey repair kit. Then to find out the 17” tires are odd size and need to be ordered. I wasn’t realizing the 17” are an odd size too. I’ll be sharing the spare tire info with her.
You can easily calculate it using the ideal-gas law if you convert fahrenheit to kelvin and the gauge pressure to the absolute pressure (the latter being higher by 14.7 psi). Then, the absolute pressure is proportional to the temperature for constant gas volume and constant gas quantity. Nevertheless, without physics knowledge, it is just about 1.0 psi for every 10 ℉ change. However, when the temperature drops to near or below freezing, the moisture content inside the tire can cause a sudden large drop in the tire pressure. That is why some people use nitrogen fill. I use 43/42 psi front/rear on mine—I have experienced zero tire wear in 50,000 miles as a result. Ignore the recommended tire pressure—it is for ride comfort only. Up to about 44 psi on 51-psi tires is OK, but don’t go any higher than about 44 psi, as you start overstretching the tire.
Thanks for clarifying. I mentioned above that I decided to compromise and set them at 38F/36R because I was concerned about the increase as it gets hotter. I don’t mind the rough ride although I was on a grooved highway (prepping for repair) yesterday and my steering wheel was vibrating like crazy despite slowing way down. I want to prevent premature rattling for sure. Do you mean no uneven wear at 50,000 miles? At least now I know the numbers on the dash are not accurate. Still nice being able to keep an eye on tire pressure.
Tire rotations every 5,000 miles are crucial to prevent wear. Front should go to rear and rear should be crossed to front. It makes no sense for all four TPMS sensors to be inaccurate by the exact same amount. Are you sure your tire-pressure gauge is not faulty?
He used a digital gauge and verified that all 4 tires were at 40 psi when the dashboard display said all tires were at 42 at one point and 43 at another. I was surprised but I had been for-warned that the display readings could be 2-3 psi off. After he changed tires to 38F/36R the dashboard display stated 40F/38R which is what I was aiming for. I always rotate tires every 5k. Must admit I haven’t done the 1000 mile oil change. Will definitely be doing every 5000 miles.
Those digital gauges have an accuracy of about ±3 psi. You should get your own gauge, some higher-rated one on Amazon or such. You should trust your TPMS readings, not the cheap-gauge readings. Those sensors are ten times more expensive. Tire gauges, especially those used by the general public, are not always perfectly accurate. While some may claim accuracy within +/- 1 PSI, they can be off by a larger margin, sometimes 4 or 5 PSI at higher pressures, especially under varying temperature and humidity conditions. Direct TPMS: Direct tire pressure monitoring systems (TPMS) use sensors inside each tire and are generally accurate to within 1 PSI.
If my car display was saying all 4 tires were at the same pressure and his gauge confirmed all 4 tires were at the same pressure (although 3psi less) why would I be so concerned as long as I keep the tires at a safe pressure until I get them checked again? When I purchased the car the dealership had most likely set all 4 tires at 38psi back when it was cooler out. I thought they had set them to 40 because that’s what the display initially was telling me before I knew it was off my 2-3 psi. I’ll get them checked again next week somewhere else before it gets hot. Bottom line is if the sensors are accurate I personally don’t want to be driving around with them at 43psi risking that they will go beyond 45 on hot days. Forgot to mention that the digital gauge used today was the same one used to check my 2009 a couple of weeks ago and all tires were at 35psi which was spot on.
TPMS readings should generally be more accurate than a cheap digital tire gauge. You can try to buy more than one gauge and different types and brands to verify if the gauge is accurate. The digital gauge on my pump shows the same reading on my pencil spring gauge, and my TPMS doesn't show the readings. However, one caveat is that the TMPS does not update frequently to save the nonreplaceable cell, and it may not update at all when the vehicle is stopped. But when it updates, it should be accurate to about 1%. If you are seeing a discrepancy with the gauge at all times, then the gauge is definitely wrong and you should get a new gauge. As those gauges are notoriously inaccurate, you can’t take a single gauge as gospel.
