My tires all at 22 PSI

that sounds low, but i don't know the trigger. yes, air temp has a large effect, but i suspect you were low to begin with.
how often do you check it? what pressures are you running? if 34, consider 38/36 f/r or something similar. gives you more time between fills, and better range. i run 42/40, but the ride can be a bit harsh.

 

I run my Ecopia 422 tires all at 39 (max pressure is 44 on these Japanese tires).

Factory spec for non-touring is 36 front / 35 rear. Eco is 39 front / 36 rear.

Touring spec is 33 front / 32 rear.

 

Many decades ago, I was told there is only about 3-5PSI difference between HOT and COLD tyres (ie, add about 4PSI if checking when they're HOT.

I suspect the gauge was incorrect, particularly seeing they all were the same. Service Station forecourt gauges are often bad and will read wrong - possibly the service centre had a bad gauge. Or - is the one which told you 22 correct? Could be both.

Now you've got them right, check them every few weeks and see how they go - but use the SAME gauge.

I found this - I couldn't spot which version is installed in PRIUS.

Toyota Global Site | Technology File

 

Yeah you can verify that, by checking them cold and then hot. I'm rarely adding air at a service station, but If I am, will just check the pressure before starting, then bring them up say 4~6 psi, and re-check them when cold.

 

Toyota’s New Car Features book says the warning appears “When the tire pressure decreases to approximately 75% or less of the default tire pressure set during system initialization.”

Yes. T-SB-0345-08, “Tire Inflation Pressure Compensation and Adjustment,” which someone uploaded in another thread, explains how this works.

 

Sure, nobody's repealed Boyle's Law yet that I know of.

The temperature compensation TSB linked above suggests that the difference from FL in the 80s to NY in the 20s ought to be worth about 5 psi, all else being equal. Maybe you also lost some air on the way, or they were a bit low to start with. While in FL, had you confirmed the pressures were right?

The TPMS waits too long for my taste to give a warning. I pumped all my tires up to the max sidewall pressure, pressed the TPMS set button then, and afterward let the air out back to a less tooth-rattling pressure. That way the TPMS lights up a lot earlier when the pressures get low.

-Chap

 

If you were a football fan living in New England you might know better.

That said, I wonder when this car had its last oil change, or service. Hard to believe that a dealer checking tire pressure could ever let a car leave the bay with all 4 tires that much under, but who knows?

The other thing I wonder about is your tire gauge — though the TPMS alarm suggests that is not it.

 

Yipes!

Didn't they look a little mushy?

 

22 PSI would probably not be noticeable visually - particularly if all 4 were low.

BUT - I'm surprised that it didn't feel like the Queen Mary while driving it. I always add 2 or 3 PSI after service (my choice to have them higher), and it's noticeable in driving feel.

 

I hope you check the pressure first. When I took my Prius in for 5K check they wrote they set all tires to 32 psi, which is low for a Prius. They were actually all at 39 psi.

 

They've always been close to specification, I just add an extra 2-4 PSI. Pressure gauges are often inaccurate, and some are inconsistent. I've got a hand one - whether it's accurate, I'm not sure, but it's consistent.

 

The fact they were 22 pounds means your dealer didn’t check them, chances are they have the same air the factory put in, if it were just one I’d say check the valve stem, but, in your case get a good air gauge and pump, and check once a month.
You lose one or two pounds a month, the max pressure on the sidewall is 1/2 the bursting pressure, just like bicycle tires.

 

They (the tire manufacturers and the auto manufacturers) want you to check/fill the tires -before- you drive the car or at "room temperature" (20C or 70F). If it's colder add more air. If you've been driving the pressures -will- be higher, but that's not a problem, it's "normal" and desired. I bump up Pearl S' tires to 42 front and 40 rear in winter, sometimes a bit more. I run 40 front and 38 rear in summer. Rides a little rougher but it's good to have some spare air.