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Really Nissan / Renult?
It's taken HOURS just to properly register 3 of the 4 tires accurately:
View attachment 1739
Like I stated.. these were
Digitally Set so I know the pressures were set equal across all 4.. maybe by the time I drive this nissan sometime this week the 4th tire will register properly..
Lord.. this car..
Precision vs. accuracy. Just because a device is reading a pressure measurement and providing the result digitally doesn't mean that result is accurate. One could make a tire pressure reader that would give you the reading in any number of digits (e.g. 41.5987654325432 lbs) but that doesn't mean that the pressure really is 41.(etc) lbs. The precision of a device is independent of the accuracy of the measurement the device is taking. You presumably used the same device for all 4 wheels, which means they would all have been filled according to the accuracy of that one device (whatever that accuracy is).
If your digital pressure measurement is also precise (not accurate, precise) to the pound (and not tenths) and a pressure sensor is inaccurate by 1 tenth of a pound (which is really quite good) then you can get a pound higher reading.
How?
You fill the tires. One, by chance, ends up at 41.4 lbs of pressure, by your measuring device. You see 41 lbs on your measurement device.
The pressure sensor in the tire only needs to be off by a tenth of a pound relative to your device - a reading of 41.5 lbs - to show 42, because it rounds to the lb.
Or, if you filled the tires to 42 lbs (by your device), but they end up at 41.5 lbs (which would round to 42), the pressure sensor in the tire only needs to be different by a tenth of a lb less (41.4 lbs) to show 41 lbs.
In either case, most digital tire pressure measurement devices, and tire pressure sensors in the tires, have stated accuracy of somewhere between .5 and 1 lb(*) (a measurement of "42 lbs" could be 41-43 lbs - good enough for tires), so yours are well within the manufactured tolerance for the measuring devices.
Given that three of the tires are reading 41 and 1 reads 42, if you filled them to 42, it's more likely that your device and one of the tpms sensors read a half lb or so high than that three of the tpms sensors read low.
(*) Doing a quick search, I didn't find the stated accuracy for Nissan's sensor specifically.
