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^ To add to that -

Remember that sun exposure can also drastically affect pressures.

As a quick and fun experiment, @nik , fill your tires first thing early in the morning after having driven as little as you can to the fill station (a small "pancake" or other similar home-pump usually costs < $100 and is great to have on-hand to help maximize tire wear). Drive home and park the vehicle with one side facing the sun and the other in the shade.

Take a pressure reading (using your manual "hand" gauge) after about 15 minutes. You'll see significant pressure differences between the shaded versus sun-exposed sides.

For a personal example, a few summers ago, I once filled my wife's Forester XT's tires to-spec, cold - and later that day when I took her vehicle to pick my daughter up from day-camp, sitting in line as the sun beat down on half the car on a very hot summer day, the TMPS warning alerted due to excessively high pressures on that side of the vehicle. A few minutes later as I was able to move the vehicle into the shade, the warning went away.

As @Ruben Marin noted, normal driving will itself cause noticeable pressure differences in the tires as they heat/cool from friction. This is a neat video that shows what it looks like inside the tire carcass as your vehicle rolls down the road.

To-wit, if you look at the last two decades or so of the most rigorous and highly-regarded winter tire tests from Europe and Scandinavia, regardless of how cold the roadway/testing surface is (well, well below the "45-deg. F. switch point" advertised by tire dealers and retailers), you'll see that "summer tires" hold significant performance ADVANTAGES until there's actual frozen precipitation (snow/ice) on the roadway/testing surface. When I asked a Michelin tire engineer why this was the case -when tire retailers warn us of dire consequences to the contrary (i.e. that summer tires "turn to rock" at such temperatures and driving on them in cold but clear conditions is tantamount to suicide) he replied that it was simple: tires generate their own heat as they perform the work they're designed to do, while being driven.

Another fun and quick experiment -now that you know the reasons behind the "why"- would be to take a quick left- or right-handed turns only trip "around the block." Monitor your TPMS as you do so, and you'll see how the different loads experienced by the different tires manifests as observable pressure changes.

I'm OCD - I'm a nerdy benchtop research scientist by trade and training - so you can imagine how the kind of readings you pictured bothers me. :) Luckily, I'm also self-confessed tire nut (I currently have 4 sets of tire/rim combos - factory OE, and aftermarket A/T and two sets of winters for my Ascent), so I've been able to somewhat temper that obsession. 😅 :ROFLMAO:

Finally, if you live somewhere where there's a lot of temperature variation throughout any 24-hour period, you can also see rather shocking tire pressure changes, even with the vehicle totally stationary. The rule-of-thumb is 1 PSI for every 10 degrees (F.). For us here in NE-Ohio, we've had a stretch of days over the last few weeks where temperatures were near-freezing in the AM, warming to well over 70 in the sun in the PM. As a result, depending on when exactly you looked at the dash TPMS readout, it's pretty LOL! ;)

Hope this helps!
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