[MotoWPK]

Recently noted on the iDrive screen displaying the current pressure, recommendations that are different than the door jamb label.

My 2019 has 265/50 R 19's, and the label states 33 psi/41psi - F/R, while iDrive indicates recommended pressures of 37psi/44psi.

So, which is correct and why would they differ - a later BMW recommendation included in an iDrive update?

[TurtleBoy]

Both are correct. The iDrive recommendations are adjusted for temperate and the label is for when the tires are cold. I think 60 degrees but in general not driven for a few hours.

[MotoWPK]

So, the iDrive indication assumes the tires are warm from driving? But, I've noticed that they indicate the same, higher pressure than the door jamb whether the car has been in motion or not. One would think iDrive would specify the same pressures if the car had not been in motion for an extended time.

Related, I'd set the pressures yesterday, tires cold but in my 55 degree garage, then today after a 50 mile drive to Denver in 30-35 degree weather, checked iDrive and it indicated the same pressures I'd set the day before, within 1 psi. Interestingly, the ambient temperature of 30-35 offset the (mostly) 75 mph drive relative to the pressure being set at 55 degrees.

[TurtleBoy]

Originally Posted by MotoWPK

So, the iDrive indication assumes the tires are warm from driving? But, I've noticed that they indicate the same, higher pressure than the door jamb whether the car has been in motion or not. One would think iDrive would specify the same pressures if the car had not been in motion for an extended time.

Related, I'd set the pressures yesterday, tires cold but in my 55 degree garage, then today after a 50 mile drive to Denver in 30-35 degree weather, checked iDrive and it indicated the same pressures I'd set the day before, within 1 psi. Interestingly, the ambient temperature of 30-35 offset the (mostly) 75 mph drive relative to the pressure being set at 55 degrees.

No, it doesn't assume they are warm, it takes the current temperature of the tires into account. You would think but I have not seen that to always be the case. There is also a speed option in iDrive that effects the pressure recommended but you likely haven't checked that box.

[jad03060]

Each TPMS broadcasts four things, about every 30-seconds after it detects motion and after stopping, eventually goes back to sleep:
- tire pressure
- temperature
- unique identifier number (sort of like an Ethernet adapter...each one has a unique identifier)
- battery level

On a hot winter day, you'd notice the side/end of the vehicle parked facing the sun could be quite a bit hotter than the other side, and with corresponding actual and recommended pressures.

Seasonal temperature changes will, sometimes significantly, affect the internal tire pressures. THe pressure changes about 1#/10-degrees F, and also changes with altitude changes, but not as fast unless maybe if you live at the top of a big mountain!

The general recommendation to only adjust tire pressure when cold is overcome by knowing what the internal temperature is, so you can top up anytime if you use the recommended values versus the generic pressure on the label.

[hufington]

I use the IDrive numbers to monitor the current tire pressures and check manually once in a while using the door jamb recommendation after the tires are fully cooled down.

[Guy Fleegman]

After 6 months owning the car and scratching my head over the inflation numbers, I realized that my iDrive had the wrong type of tires listed. I would have thought that setting would have been done at the factory or dealership, but no.

The recommended pressures reported on the app are practically useless as they seem to change every few minutes. I could spend all day inflating/reducing my air pressure.

[MotoWPK]

Thanks for the info...did not know the TPMS monitors passed info other than pressure and battery state to iDrive.

I've read previously of iDrive having the tires on the vehicle listed and wanted to check that, but, was unable to find it. Where is that listed in iDrive?

[TurtleBoy]

Originally Posted by MotoWPK

Thanks for the info...did not know the TPMS monitors passed info other than pressure and battery state to iDrive.

I've read previously of iDrive having the tires on the vehicle listed and wanted to check that, but, was unable to find it. Where is that listed in iDrive?

On that page:

[Flying Ace]

Idrive

[nZtiZia]

Originally Posted by Guy Fleegman

After 6 months owning the car and scratching my head over the inflation numbers, I realized that my iDrive had the wrong type of tires listed. I would have thought that setting would have been done at the factory or dealership, but no.

The recommended pressures reported on the app are practically useless as they seem to change every few minutes. I could spend all day inflating/reducing my air pressure.

this is a lot more common than it should be!

[nZtiZia]

this is my first DD bimmer, and TPMS behaves differently than in my previous three Audis. at first, I was always ‘chasing’ the recommended pressures shown on the TPMS screen, but later realized this shouldn’t be the case.

I did as jad03060 suggested to me in an older thread. inflated to the pressures noted on the B pillar door jamb when the tires were completely cooled at 60-70° ambient temp. I last did this in Fall 2022. so far, I’ve not had to adjust the pressures, even through the winter. I also noticed actual pressures matched the recommended pressures that would change due to driving.

[MotoWPK]

Well indeed the tire settings are right where indicated. If it was a snake...

And checking this morning I found that the recommed pressures in iDrive had changed since viewing yesterday after a drive, presumably due to temperature differences.

Rather handy. Out of habit I've always gone by the door jamb label in conjunction with a pressure guage, only rarely looking at the iDrive tire pressure display. We'll, I've only had the vehicle for going on four years, so still things to learn!