psi reading on my tires is not accurate, car says they are 37-38 psi, I connected my compressor to it and it says 33.5 psi

[E90alex]

Just let some air out if you’re concerned?

 

[gottagofast]

Just let some air out if you’re concerned?

I was late for work, haven’t had a chance

 

[RSpanner]

If tire pressures are 1>2 lbs. off, does that really matter at all? I struggle to get them all the same according to the onboard system. Example...fronts...42, rear,one at 42,one at 40.

 

[jabloomf1230]

Unless one has a "lab grade"<( tire pressure meter, one is comparing pressure sensors of unknown accuracy. And that's not factoring in the tire temperature and possibly even air temperature. As @RSpanner stated above, a few pounds here and there isn't going to matter.

One of my other cars is a BMW hybrid. After a few years, the tire pressure light came on (Shocking, I know!). I figured that the batteries in the TPMS sensors were dying, but the interesting thing was that the tire pressures displayed in the car's UI were to spec. I tried calibrating the TPMS using the car's UI and it did not make the light go out. Out of curiosity, I decided to pump up the tires with my portable De Walt compressor, set to spec. That caused the TPMS idiot light to go out and stay out. The moral of the story is ...

 

[carpe_diem]

Looks like the compressor or car is off by 4 psi, compressor said I put in 40 psi car says the tires are 44, so next time I’ll put in 38

The "car" doesn't measure tire pressure, the tire pressure monitoring system (TPMS) senor in each wheel does. The UI on the screen simply reports the value that each sensor is measuring. If all four sensors are reading close to one another but significantly different than the gauge on the compressor, the value reported by the compressor is likely inaccurate.

Do yourself a favor and buy a proper tire pressure gauge.

 

[PianoAl]

It’s one of those portable ones you can plug into an outlet, I like them for road emergencies I can fill up anywhere I am, $50

Better are the ones you can plug into the 12v outlet but which also have a rechargeable battery. It's very convenient to use without a cord.

But the forum would like you to buy a good gauge and test whether the car or the compressor is right.

And some of us would love it if you would de-animate your avatar.

 

[PianoAl]

Does anyone know why some tires go many months without needing a top up while others seem so lose 1 psi a month?

 

[tga]

Does anyone know why some tires go many months without needing a top up while others seem so lose 1 psi a month?

Dirt/dust on the rims? Bad seal in the valve stem?

 

[carpe_diem]

Does anyone know why some tires go many months without needing a top up while others seem so lose 1 psi a month?

Possible reasons may include:

- poor seal between tire and rim (eg due to damaged/defective bead, tire sidewall, or rim; over/underinflation)
- leaky valve
- poor valve steam seal
- tire puncture

 

[RayK]

Possible reasons may include:

- poor seal between tire and rim (eg due to damaged/defective bead, tire sidewall, or rim; over/underinflation)
- leaky valve
- poor valve steam seal
- tire puncture

- somebody is playing with your valve stems and letting air out

 

[RayK]

And some of us would love it if you would de-animate your avatar.

OT: If you are using Firefox, open a new browser tab and type the following into the address bar: about.config
Click the Accept the risk button and in the "Search preference name" bar type the following: image.animation_mode
Click the pencil icon (edit) and change the "normal" to "once" (no quotes)
Close the browser tab

I believe Chrome requires the use of a browser plug-in (extension) to disable animated .GIFs.

 

[PianoAl]

OT: If you are using Firefox, open a new browser tab and type the following into the address bar: about.config
Click the Accept the risk button and in the "Search preference name" bar type the following: image.animation_mode
Click the pencil icon (edit) and change the "normal" to "once" (no quotes)
Close the browser tab

I believe Chrome requires the use of a browser plug-in (extension) to disable animated .GIFs.

Yes, thanks. I haven't yet found a solution for the Brave browser. Wasting a lot of time on this.

 

[rpiotro]

...And some of us would love it if you would de-animate your avatar.

This! How annoying. In need of attention I suppose.

 

[gottagofast]

Never seen such a big deal over an avatar

 

[fholbert]

Does anyone know why some tires go many months without needing a top up while others seem so lose 1 psi a month?

Outside air temperature is increasing?

 

[RayK]

Outside air temperature is increasing?

• Temperature change should affect all tires the same, not just one or two
• Increasing ambient temperature should make the tire's pressure gain, not lose PSI

 

[Sweed269]

I've had one of these for 30 years and it's my baseline gauge for everything. All other gauges get "calibrated" to it.

Magnum™ 3 ½” Tire Gauge

<p>Tire Pressure Gauge - includes both angle and ball chucks and dual bleed buttons for faster setting.</p> <p>Huge 3 1/2" Glow-in-the-Dark face for high ...

www.longacreracing.com

 

[Dangerous Fish]

I've had one of these for 30 years and it's my baseline gauge for everything. All other gauges get "calibrated" to it.

Magnum™ 3 ½” Tire Gauge

<p>Tire Pressure Gauge - includes both angle and ball chucks and dual bleed buttons for faster setting.</p> <p>Huge 3 1/2" Glow-in-the-Dark face for high ...

www.longacreracing.com

Longacre stuff is generally good. I have one of their digital gauges and it's within 0.1PSI of my $250 Prisma Motorsport gauge.

 

[rpiotro]

Never seen such a big deal over an avatar

Then why do it? Many people find it quite annoying. Only a few will speak out. You know, you are the only one. What is your purpose then?

 

[Kandiru]

Beware of labor camp grade equipment, I replaced all my gauges several years ago with Made in Taiwan, no issues. Tesla's sensors are always within 1-2PSI of what that gauge reads.