How accurate are they?
And are there any tips on how to position the car so as to have a clear line of sight to the LCD screen? Or do you normally just count on the beep beep sound?
Do The Tyre Pumps at Petrol Stations Show an Accurate PSI Reading
jamessong on 09/06/2021 - 18:25
Last edited 10/06/2021 - 08:40 by 1 other user
Last edited 10/06/2021 - 08:40 by 1 other user
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The issue is that its measuring your tyres warm, as opposed to the recommended 'cold' measurements on your door jams.
not an issue i presume if you drive straight from home to petrol station at 7 am in the morning winter time?
depends on how far, the tyres are still heating up from friction.
People generally recommend going 3-5 psi above the recommended if the tyres are 'warm'
They are NOT accurate. They are a few PSI out normally and can be either way.
But what's better for the average person?
To be too high or too low? Neither is desirable. Under and overpressure can shorten the lifespan and negatively impact the performance of the car.
I meant what is a better measurement tool?
@Zephyrus: But you really reckon they are any better? My work has calibrated ones, but the I doubt the average Repco special is very good.
I check my pressure very regularly, and when temperature is considered I find the servo station digital gauges very similar.
Some might be… some might not be
ypmv
Yep the one I use is spot on my digital meter. unless its wrong as well, lol
What's your alternative? Should I trust the tyre gauge connected to my shed air compressor that's likely using dirty, moist air and I've dropped the gauge repeatedly?
Long as the car rides higher than previous I'm assured that air has gone in, I'll just keep checking it over time so I don't drop below that sweet, sweet "20% above rating" pressure of 40psi.
Also, how accurate is the built in TPMS some cars have?
Depends on the system, some are based on pressure sensors while others use the ABS to measure rotation speed differences between wheels.
I carry a $30 Michelin Digital Tyre Pressure Gauge in the glove box. They say it's accurate to +/- 1%. The two servos I go to have gauges that are very close to what mine reads.
no. but close enough. Better to be running +10% of your tyre placard rating than -50%!
remember to park your car in a way that lets you inspect your muffler bearings while you fill up the back tyres
Dont rely on the clip, hold the nozzle firmly on the valve stem.
Usually pretty accurate.I find the new digital automatic ones ok. They aren’t super accurate, but a lot closer than the old dial type that used to get dropped and left out in the sun and rain. IMO a couple of PSI either way isn’t a big deal.
If you are worried about it, keep your own tyre guage in the car and check against something consistent.
No need to park a special way, the beeps work well, although I’ll typically check the pressure before it starts pumping to see if the tyre is low. That usually involves connecting the hose and standing up and taking a step or two to see.
what values are you guys pumping at?
What is rated for the vehicle, they do differ.
i tested some digital ones, and they were precise but not accurate.
which bang-for-value digital one would you recommend for easiness and precision?
Go to Super Cheap and/or Auto barn, buy NON-DIGITAL tyre gauge. Keep it in car where you can quickly grab to use.
Non-digital because digital use batteries and just when you need it…
I have found that they are pretty accurate, at least relative to each other. I used to top up my tyres every time I got petrol. When I got some new Michelins I found that they were always reading the same value, regardless of which station I went to. (as they held their pressure well for a long time)
Built in TPMS have a huge leeway before throwing an engine warning like alert. Mine I think was 10psi low before it triggered. Bought a cheap $25 TPMS kit from eBay and it's shit and reads 3 to 5 PSI lower than my Michelin digital gauge when cold. But at least it should help flag an alert if the pressures drop. I notice that my tyres are losing pressure recently. Not sure if it's the cold weather, age of my tyres, a puncture or the seal against the rims. Tyres probably are due for replacement though.
The digital service station gauges seem to be pretty accurate. The analogue gauges are quite bad probably 5psi off.
When you hear the "Beep Beep" your Road Runner is full.