[Mid_Life_Crisis]

I’ve checked numerous times with my $100 liquid filled gauge as well as other dry gauges I have. Not only is the reading usually 3-5 lbs off but often shows one tire very low. Lower than the others. Not always the same tire. This is a cold reading. That said, after driving for a half hour or so, the pressures start to read more accurately although still a little high…..around 34 lbs. these are the runflats. Anyone have this issue as well?

[arpad_m]

Not to the same extent, but one of my TPMS sensors consistently shows 1-1.5 psi lower when cold, and pressures appear to slowly equalize as the tires warm up.

Now, arguably it could also be the tire and not the sensor, but I won't risk tire shops messing with my precious 1LE wheels more than absolutely necessary, so I'll probably never know...

[ctrlz]

Mine are within 1 psi on a 2017. I have a set of take offs from a 2018, also within 1 psi compared to my digital gauge.
I think these are 315 Mhz sensors. Maybe GM switched suppliers at some point.

[Vtor_ZL1]

I find mine to be very accurate to longacre gauge. I love that it updates *very* fast compared to some others cars i've seen.

[Alan47717]

Originally Posted by Mid_Life_Crisis

I’ve checked numerous times with my $100 liquid filled gauge as well as other dry gauges I have. Not only is the reading usually 3-5 lbs off but often shows one tire very low. Lower than the others. Not always the same tire. This is a cold reading. That said, after driving for a half hour or so, the pressures start to read more accurately although still a little high…..around 34 lbs. these are the runflats. Anyone have this issue as well?

I have found across several cars that the sensors tend to read low when cold and are significantly more accurate hot. Cold weather makes the issue worse. I recently exchanged the run-flats for Conti DWS06's and haven't noticed any difference in how the sensors perform.

[ctrlz]

Originally Posted by Alan47717

I have found across several cars that the sensors tend to read low when cold and are significantly more accurate hot. Cold weather makes the issue worse. I recently exchanged the run-flats for Conti DWS06's and haven't noticed any difference in how the sensors perform.

All my cars with numerical readouts on the dash actually seem to do pretty well in all 4 seasons.
The sensors are piezoresistive devices and they must incorporate some kind of temperature compensation. The sensors would be sold with an advertised linearity over a certain temperature range.

[PostalLDMC]

Every month when I get my OnStar report it got 1 tire way off. In the winter I can park the car for 3 months and every report has a tire way off. But put mt air gauge on them and all set at 35psi.

[Mid_Life_Crisis]

This is good info. At least I’m not alone and really it’s not the end of the world. I’ll try checking again when tires are warmed up with the gauge. If it’s fairly close then all good.

[ember1205]

Originally Posted by PostalLDMC

Every month when I get my OnStar report it got 1 tire way off. In the winter I can park the car for 3 months and every report has a tire way off. But put mt air gauge on them and all set at 35psi.

How are you getting the monthly reports if the car is "parked"? Sounds like you're starting it periodically?

I have found mine to be fairly close pretty much all of the time although once my car is parked for the winter, I don't do any sort of checks.

I would absolutely expect there to be some discrepancy with fairly cold temps since the sensors operate off of a battery and those don't like cold temperatures. I would be headed back to the dealer to have an accuracy check done and get the sensors replaced if they're off.

[LT1gen6]

Living in an area of wide temperature fluctuations, chasing balanced, equal tire pressures is a fool's errand. Otherwise, to achieve it would likely entail multiple daily inflation / deflation activities. For me, it's not that important for daily street driving if pressures are close.

[arpad_m]

Originally Posted by LT1gen6

Living in an area of wide temperature fluctuations, chasing balanced, equal tire pressures is a fool's errand. Otherwise, to achieve it would likely entail multiple daily inflation / deflation activities. For me, it's not that important for daily street driving if pressures are close.

Yeah, I don't worry too much about it either, +/- 1 psi is fine.

[The Maverick]

Originally Posted by LT1gen6

Living in an area of wide temperature fluctuations, chasing balanced, equal tire pressures is a fool's errand. Otherwise, to achieve it would likely entail multiple daily inflation / deflation activities. For me, it's not that important for daily street driving if pressures are close.

I have had no issues getting reasonably consistent TPMS pressure readings year round with my 2016 and 2021 sixth gens. In fact, checking the TPMS readings virtually every time I drive the car has made me more savvy in maintaining tire pressures and provided me with effective rules of thumb for various situations - airing up warm tires, when to adjust pressures as the seasons change, and accounting for the impacts of airing up a car that has been parked with one side facing the sun.

When the tires need air, I park the car in the garage and let the tires cool down from driving. I slightly overfill them by 1-2 psi (adding a factor of +1 psi for each 10 degrees that the current air temperature exceeds the average air temperature forecasted for the time I will start my morning commute). Alternatively, if I am at a shop, I give them the specific front and rear pressures I want using the same rough calculations. Then, on my next commute day, just before I depart, I use my air gauge to blip the valve on each tire, letting out small bursts of air until the tire reaches my target PSI.

I use Measurement Ltd digital gauges, model MS-4021b: http://measurement-ltd.com/4021b-det.html

No daily/multiple inflation/deflation required! Just close attention to detail about how and when you are setting the tire pressures.

Originally Posted by Vtor_ZL1

I find mine to be very accurate to longacre gauge. I love that it updates *very* fast compared to some others cars i've seen.

Agreed! The TPMS on the 2019 Subaru Outback seems to take forever for the PSI to come up at the start of a drive, and displays "--" until then. The sixth gen starts with what I am guessing is the last reading before the TPMS sensors "went to sleep," and they all come online with current readings shortly after the tires start rolling.

[Mid_Life_Crisis]

Good info!

[SuperSnake1972]

I don't trust tpms as much as my $2 tire gauge.