You can still get a lot of water from a compressor tank, what helps is having the moisture separator or dryer.
So if I use one of those compressors at the gas station where you drop in 4 quarters and get so many minutes of air, is that coming from a tank or is it just compressing ambient air? I doubt that it comes from a tank.
I don’t know of any place around here where you can use the air that the garage uses. In fact, for the most part, “service stations” (where you can get your car service or repaired) and “gas stations” (where you can fuel your car) have become separate things.
Your Harbor Freight gauges are only 8 off?
The last one I bought never read above 16, even on my work truck that runs 80 PSI…
Just do what I do - a little piece of black electrician’s tape works wonders for a persistent little Check Engine light. I’m sure it would work for a TPS light too. 
Do NOT just leave the light on and ignore it. My 2012 Honda Fit has the same issue, and after a check the dealership mechanics told me it was fine, but to check the pressure every two weeks or so and re-inflate it with a couple of pounds whenever necessary. So it went on, and off, and on, and sometimes it went off after the car warmed up a bit, and eventually I just ignored it when it was on all the time.
Then, it went on and stayed on, and as usual I ignored it. But this time what I was ignoring was a nail in my tire and a slow leak that resulted in a total flat, on Boxing Day, 400km from my home, necessitating an expensive new tire and four hours of delay. Thanks to the delay, we got caught in a huge snowstorm that was so bad we had to stop for the night in a hotel as the highway was piling up snow and no plows were anywhere to be seen.
So ignoring the TPMS light eventually cost me about $500 in a new tire and a night in a hotel, and a huge and massive inconvenient pain in the ass. Now I check my tires religiously.
The sensor that cried wolf. Yes I do want to know when my tires are low. But don’t be so damn sensitive about it.
It’s not at all unusual for 60 degree temp swings when I’m driving. And the stupid light will come on when I’m a pound low.
It would be really, really nice if they just put a digital display on the dash of the actual pressure on each wheel.
No, it comes on when you are 20% below the factory recommended pressure. That translates to 6 or 7 lbs below the recommended pressure.
Don’t forget the reason for TPMS is the failure of tires on Ford Explorers due to low pressure and the resulting injuries and deaths.
That may be so, but one time the sensor for my nitrogen filled tires came on when it was only 2 lbs low (was 30, should be 32). And that was on only one tire.
I suspect your gauge is/was inaccurate.
I wish. 20% is a reasonable amount. I suspect I must have some bad sensors. One or two pounds sets it off. It’s nuts. I ignore it for the most part.
Unless you need better traction. In the winter, on icy streets, tires filled to rated pressures don’t get as good traction as tires that are a tad below.
As mentioned above, that also leads to extra sidewall wear, which isn’t good. It also costs a bit in gas mileage.
Maybe this isn’t the best advice with modern tires, but it used to be the case. I live in NC now, and don’t need to care since we rarely get ice here. In Southeast MI it was often very useful to run a bit low, thanks to all the freeze/thaw cycles in a typical winter.
What kind of car? I’ve seen a couple Infinitys that came on for 1lb lower than the recommendation. All four tire pressures were shown on the dash display too, and if three were on 35 and one was on 34, the light came on. This was about 5 years ago, I imagine they changed it since then because that would drive people nuts.
The only way you’ll get permanently-condensing moisture out of a compressor tank filled to high pressure is if you withdraw freshly-compressed air before it’s cooled back down to room temperature (and left most of its moisture in the tank). For certain applications like spraying paint, yes, you absolutely need an air dryer downstream of the tank, but if you run through the thermodynamic analysis, you will come to this conclusion:
room-temperature air from a 150-psi storage tank that is delivered to a 32-psi tire will not produce standing liquid water inside the tire.
The air in the tire may contain some non-condensing water vapor, but the amount is tiny (relative to the rest of the air), and its pressure/temperature behavior close enough to that of dry air so that the overall pressure/temperature behavior of the mix is almost identical.
Given that the compressor runs continuously after you drop in your quarters - and you don’t get any air after the compressor stops running - you are correct, there is no tank on those particular units. However, in order to get a lot of moisture into the tire, you’d need to use one of these compressors on a fairly humid day. If ambient relative humidity is over 30%, you will get some water condensing inside your tires, but very little, unless the humidity is very high.
It’s worth noting too that the big effects from having water inside the tire occur when the temperature goes up. If you have enough standing water inside your tire, and you raise the tire’s temperature from 70F to 200F, you’ll see the pressure climb by about 14 psi above and beyond the pressure increase you would see inside a dry tire (and your tires won’t see those kinds of temperatures unless you’re running the Indy 500). However, no matter how much liquid water you have inside your tire at 70F, if you cool it down to 20F, the pressure will only drop by about 0.3 psi.
Some do, I can display that or the amount each tire deviates from the recommended norm or switch to something else like mpg. But the dedgum warning “!” stays on until a pressure deficeincy is corrected if it senses such. Or are you saying just display the values and dispense with the warning?
Nissan Pathfinder. And I don’t have the individual displays so it sort of sucks that they are so sensitive.
In a shop environment it is not unusual to get water out of the air lines due to the high demand.
When I worked as a tech I ran the shop air line to my box where I had a drier/filter. I would have to drain it regularly.
Yep, I have the same issue when I’m sandblasting: the air leaves the compressor tank before it’s had a chance to cool off and leave its moisture behind. It gets in the lines, and then my dryer (a coalescing filter + a desiccant) catches it.
I may not have worded it clearly but my point was just that having a compressor with a tank doesn’t mean you won’t get water in the line. People were asking where to find a compressor with a tank, as if the presence of a tank would ensure it’s moisture free.
I really meant both. The ! for non-tech-non-mechanical folks, and the other part as a bonus for folks that want details.
And, actually, the display would help non-technical folks know which tire they need to attend to… and save them some time. I’m sure most people handling these issues can figure out what the displays mean.