Accuracy if tire Pressure gauges rant

[afterburn 549]

when one starts to get really fussy, a temp reading gun is used across the treads of a tire.
Hotter in the middle? reduce pressure. Etc

[Rusty Heap]

Getting a GOOD low pressure gauge is critical for ATV or SxS tire pressures, heck even riding lawn mowers too. Typically I run only 8-10 psi or less. Sometimes as low as 3-4 psi. Heck at 10 psi a +/- 2psi is 40% spread range!

[masraum]

I have 3 of these, and they all read the same as each other, and I've compared them to others and found that they seem to be consistent. I have found one or two devices that don't match or read consistently, and that's why I settled on these.

Originally Posted by Dixie

Thanks, I didn't know this.

I always rationalized using one gauge that reads consistently is the secret. If it always reads 32 lbs as 30 lbs, so be it.

Yeah, as long as the reading is consistent and close, you should be good. Presumably, if you're filling to 32, and the vehicle feels off, you'll try 34 or 30, discover that you've fixed the feeling, and then stick with the new reading. So whether the reading of 32 is 32 or 30 or 34, you should be Ok. Obviously, if it's reading 30 when it's 40 or vice versa, that's a big enough discrepancy that you'll be thinking "no way in hell should I be running "xx# of air in these tires" and won't ever get to the "right" reading. I don't think most of us need F1 levels of accuracy.

Another thing to remember, many gauges have a range where they read pretty accurately. For instance, if you are wanting a scale to weigh yourself, the avg scale is probably going to be pretty good from 75# up to 250#. But if you're down at 50#, 25# or less, or up around 300#, then I wouldn't trust the reading much. For most cars, you're likely to want decent readings in the 20-25# up to 50# range. Obviously, for some vehicles, you may need a low pressure gauge (mowers, ATVs, etc...) or a much higher pressure gauge (road bicycles, big trucks, etc...). I wouldn't trust a gauge that was good for truck tires at 100psi also being very good for checking a tire at <10psi.

[911 Rod]

I use my TPMS reader if I want exact. Assuming the monitors are exact.
It's really hard to get each tire the same at 1/10th of a pound though.

[masraum]

Originally Posted by 911 Rod

I use my TPMS reader if I want exact. Assuming the monitors are exact.
It's really hard to get each tire the same at 1/10th of a pound though.

I've never shot for 0.1# as a threshold. On my car, I shoot to have tires matched within ~0.5#. If I get the pressures matched per my gauge, then my TPMS reads the tires matched side to side and within a pound or two of what I saw on my gauge when I filled them (which of course will vary with ambient and/or tire temp) If I am off by 0.5# when I fill, then my TPMS will often read a 1# difference between the two tires which bugs me, so I'll sync them up. But I have to be careful to not try to sync them when the car is or has been sitting in the sun. I can jump in the car when it's sitting in the sun in the summer and the tires on the side of the car that were facing the sun can read 2-4psi higher than the other side, until I've driven several miles so the temp/pressure can even out.