BMW X3 Forum
BMW X3 Forum
Welcome to the ultimate BMW X3 community.
BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read
Post Reply
 
Thread Tools Search this Thread
      09-19-2011, 04:18 PM   #1
flash3
Captain
68
Rep
654
Posts

Drives: X3 28i
Join Date: Feb 2011
Location: NC

iTrader: (0)

Question Tire Pressure on 28i

Guys,

I was prepping a list of things to do before I leave on my road trip from NC to FL, and one of those 1st things is to confirm tire pressure, so based on what it says on Pg 207, it looks like it's 32PSI front and back, is it not?
Appreciate 0
      09-19-2011, 08:13 PM   #2
flash3
Captain
68
Rep
654
Posts

Drives: X3 28i
Join Date: Feb 2011
Location: NC

iTrader: (0)

Always great info, Lotus! I will need to check my Tire Pressure this week to see what I am at and then will see what to do next, but I did want to make sure what I needed to be at.

I will DEF be driving under 100 -- those cops in GA DO NOT PLAY AROUND!
Appreciate 0
      09-21-2011, 08:52 PM   #3
flash3
Captain
68
Rep
654
Posts

Drives: X3 28i
Join Date: Feb 2011
Location: NC

iTrader: (0)

Lotus, I am planning to put some air tomm in my tires -- how do I reset the TPMS? I'd reference the pdf manual, but I won't have access to a computer until well after tomorrow or the next day. :/

fwiw, I am going to get the air pressure filled @ Costco, since they have a Nitrogen tank and it's closer than going to a BMW dealer here. What should I do before and/or after, I should ask

Last edited by flash3; 09-21-2011 at 08:59 PM..
Appreciate 0
      09-21-2011, 09:00 PM   #4
Want the thrill
Lieutenant Colonel
326
Rep
1,560
Posts

Drives: 2022 X4M40i, retired ‘11 X3
Join Date: Mar 2011
Location: MI

iTrader: (2)

Garage List
2022 X4M40i  [10.00]
Quote:
Originally Posted by flash3 View Post
Lotus, I am planning to put some air tomm in my tires -- how do I reset the TPMS? I'd reference the pdf manual, but I won't have access to a computer until well after tomorrow or the next day. :/
It's right in the I-drive menu I believe under the vehicle status (can't remember exactly off the top of my head).
Appreciate 0
      09-21-2011, 09:28 PM   #5
flash3
Captain
68
Rep
654
Posts

Drives: X3 28i
Join Date: Feb 2011
Location: NC

iTrader: (0)

+1 guys!

Lotus, so it auto-reads the pressure of each tire after I put in more air? Neat-o!
Appreciate 0
      09-21-2011, 10:18 PM   #6
flash3
Captain
68
Rep
654
Posts

Drives: X3 28i
Join Date: Feb 2011
Location: NC

iTrader: (0)

Always useful info, sir!

Tomm, I'll put in more air, and then immediately reset the TP Monitor and drive around the parking lot for a few minutes until I see the tires turn green on the iDrive.

Does that sound good?
Appreciate 0
      09-22-2011, 12:27 AM   #7
tuco44
Colonel
tuco44's Avatar
Canada
644
Rep
2,294
Posts

Drives: 2018 340i xDrive M Perf Edtn
Join Date: Apr 2007
Location: Western Canada

iTrader: (0)

Lotus 7 is probably the most knowledgible and helpful poster on this site.

Kudos to you, Lotus 7.
__________________
2018 340i xDrive M Perf Edtn Sunset Orange
Previous BMWs - 19 others since 1971.
Appreciate 0
      09-22-2011, 12:33 AM   #8
sfax
Brigadier General
sfax's Avatar
United Kingdom
91
Rep
3,855
Posts

Drives: BMW X3 2011 F25
Join Date: Nov 2010
Location: Berkshire, UK

iTrader: (0)

Quote:
Originally Posted by Lotus7 View Post
Yes, but only if you go through the reset procedure.

For instance, if you set the tire pressure to 30 psi, then reset the system, and the low tire warning triggers at 26 psi - that's a reasonable safety margin. However, if you then decide you's like to run at 40 psi and don't remember to reset the system, the tires would still have to drop to 26 psi. If you do reset the system, a much smaller drop (4 or 5 psi) to 35 psi will give you a warning of a tire going down.

As far as I can tell, each of the (4) TPMS transmitters has a unique ID code it transmits. When I put on my new winter tires just to confirm that the wheels fit and the TPMS transmitters actually worked, I set the pressures to exactly the same as the All-Seasons tires I was taking off. The TPMS error light went on, but resetting and driving a half-mile corrected it. When I put the original All-Seasons back on the TPMS again triggered until I again went through the reset procedure.

Resetting apparently not only checks the pressure, but reads and remembers the transmitter ID code. I guess they don't want TPMS lights being triggered by cars in the next lane.

The driving part is required because the TPMS transmitters shut off when the vehicle is not moving (undoubtedly to save battery power). You have to move the vehicle to get a pressure signal from the wheels.
Goes without saying really but you still need to check the tyres regularly because the monitoring only detects differences in rotational speed between the vehicles wheels. Therefore, they could all go down at the same rate over time and it wouldn't trigger the warning. However, if just one tyre dropped in pressure so it was below the others it would
__________________

F25 xDrive20d SE __ professional multimedia package | dynamic package | climate package | 309s | xline | xenons | electric seats | folding mirrors | business speakers
Appreciate 0
      09-22-2011, 07:53 AM   #9
sfax
Brigadier General
sfax's Avatar
United Kingdom
91
Rep
3,855
Posts

Drives: BMW X3 2011 F25
Join Date: Nov 2010
Location: Berkshire, UK

iTrader: (0)

Quote:
Originally Posted by Lotus7 View Post
sfax,

Depending on market, X3's use (2) different systems to determine tire inflation loss. In the US, all X3's seem to be delivered with actual TPMS transmitters and a receiver that monitors the individual tire's pressure. The vehicle will trigger if a single tire looses pressure OR if all tires loose pressure.

That system can be identified by checking your tire's valve stems. If they are all metal, the vehicle uses the battery powered, radio based (433 mHz), true pressure monitoring system.

Some Canadian vehicles apparently use the "older" wheel speed sensing system which works as you've described. If all tires loose pressure at the same rate, no alarm will be triggered. Vehicles that use the rotational speed sensing system can be identified by their use of rubber valve stems. Those vehicles do not need, and cannot benefit by the use of the $50 (each) TPMS transmitters.

I have no idea which system is used in the UK or in Common Market countries. It may be based on local legal requirements, and/or local radio channel allocations.

No matter which system you have, it's always a good idea to check tire pressures with a good, known accuracy gauge. I check once a month and often have to make minor adjustments, and of course, during spring and fall when temperatures are changing, the adjustments are greater.

However, I have noticed that during months when the temperature is stable, the run-flat P7's that came on my X3 seem to hold a constant pressure better than almost any other tire I've used, and that's "lot's" of tires. Maybe they're fitted "tighter" to the wheels, or the sidewalls are less permeable, but they just don't loose are as fast as other tires.

Has anyone else noticed this, or is it my imagination?
Aha, thanks, I didn't think we'd have different systems. I guess it must be a legal or marketing thing.

I think we are in the wheel speed sensing camp in the UK as that's how it's described in the 20d user manual with a specific warning about not relying on the sensors. I check mine about once a month or before long trips and they do seem to hold their pressure well
__________________

F25 xDrive20d SE __ professional multimedia package | dynamic package | climate package | 309s | xline | xenons | electric seats | folding mirrors | business speakers
Appreciate 0
      09-22-2011, 08:26 AM   #10
flash3
Captain
68
Rep
654
Posts

Drives: X3 28i
Join Date: Feb 2011
Location: NC

iTrader: (0)

Lotus, is a knowledge base of info making me think he's actually an X3 Transformer

Lotys - qq - if the idrive system is NOT coming on and saying low pressure and I am simply adding more pressure, do I still need to reset the TPMS?
Appreciate 0
      09-22-2011, 08:45 AM   #11
flash3
Captain
68
Rep
654
Posts

Drives: X3 28i
Join Date: Feb 2011
Location: NC

iTrader: (0)

Lotus*

--silly iPhone spell checker
Appreciate 0
      09-23-2011, 08:14 AM   #12
flash3
Captain
68
Rep
654
Posts

Drives: X3 28i
Join Date: Feb 2011
Location: NC

iTrader: (0)

The weather was too bad yest that I didn't take my X3 out of the garage

I'll prob take it this weekend
Appreciate 0
Post Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 10:14 AM.




xbimmers
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST