That's a huge difference. If it were me I'd first try to confirm the dial gauge reading. It doesn't take much to make them read low.

 

 

If they are not correct then you may need to re-calibrate the TPMS by resetting it Please share your findings. .

 

Hand-held dial gauges are nice until they get dropped, or bumped, or looked at a little cross-eyed. Then they are junk.

Digital gauges tend to be more reliable, in my experience.

 

FWIW: I use an Accutire MS4400B digital, tire gauge.Very accurate, and easy to read, even in dim light. Most stick type gauges, are difficult, for me to read. Most dial type gauges, seem to loose their accuracy, quickly.

 

 

 

It's the gear-head in me but it would be cool if tire temps were shown along with PSI, rising tire temp is more indicative of an impending failure. I saw that the new McLaren shows this and my nephew test drove a 2018 BMW X3 and he said it also shows individual temps along with the PSI. I'm a sucker for telemetry, maybe I should buy a Nissan GTR. Pssst, I kinda wish the boost gauge also showed PSI. The more info the better (configurable of course)

 

Don't forget to check the spare (if you have one). Sometimes they are not set properly from the factory and the PSI can drop 1-2 per month. I got into the habit of setting the spare PSI to about 5-6 over to account for normal drop over time. I check my spare when I do my M.I.D. oil changes.