Just wondering whether anyone has measured the accuracy of the TPMS. I have a digital small air compressor that I bought at Ace a number of years ago. Harley's TPMS always measures 1-1.5 PSI lower than my gauge. Not a big deal, but I do keep track of my pressure and would like to rely on HD when I start the bike if possible.

 

Mine is not what I'd consider a large sample, I'm just one person. I inflated my tire to 36PSI and the TPMS read 36PSI for that tire. But, my little gauge reads 1 off from that, so I'd say it's all just a round about guess. Temperature affects the pressure by as much as 4 plus or minus, so I'd say that 1 or even 2 off is not a big deal.

 

Kinda the same here, one sensor reads a pound more than my "good" gauge and the other reads a pound less.... so I go with 38F/40R cold at 70F and have never had an issue. I have 3 or 4 gauges in the garage and none of them read the same, FWIW, but they are all within a couple pounds of each other +/-

 

Sounds good. Since my electronic gauge reads higher, as long as TPMS is good, then I won't worry. Appreciate the feedback.

 

I could say that my TPMS is spot on with my compressors gauge or they both have the same abnormality

 

Here’s an excellent excellent explanation on how TPMS works.

 

Mine are usually very close to the pressure set with a gauge, on both bikes.

 

HD tells you right out not to rely on it. It is a tool. TPMS does not stay updated 100% of the time. If you finding that close with any two ways to check it call it done. TMPS is more of a good to go thing.
This morning the weather was cool 30 degrees. front read 31 rear 36. yesterday they were spot on 36 and 40. After 20 minutes of riding they were back to normal.
Once in awhile TPMS will get a bug and not register or stay on an older pressure for awhile. Easy way to wake it back up is
let 5 pounds out. Then put it back where it belongs. Using tire gauge not TPMS.