03-24-2014, 10:20 AM | #1 |
First Lieutenant
44
Rep 336
Posts |
How is tire pressure measured for FTM?
While perusing the 'Quick Reference Guide' this morning, I found the following quote on page 29:
"Flat Tire Monitor The system identifies a loss of pressure by comparing the speeds of rotation of the individual wheels as the car is traveling." I would welcome this as a fact, because I plan to buy winter tires on rims for next season, and avoiding the electronic tire valves is a time and money saver. My bride's Audi uses the 'tire rotation' method, and it has worked very well. Any more info? I presume the factory brochure should be right, but I thought I had read elsewhere that electronic stems were involved. Moon |
03-24-2014, 03:15 PM | #2 |
Lieutenant Colonel
658
Rep 1,922
Posts
Drives: 2011 e91
Join Date: Jan 2013
Location: Calgary, AB, Canada
|
U.S. spec has the tpms as part of the valve stem or whatever.
__________________
2011 E91
2016 M2 - Sold 2014 X1 - Sold 2002 Land Rover Discovery II - 3" lift & 33s |
Appreciate
0
|
03-24-2014, 04:31 PM | #3 |
First Lieutenant
44
Rep 336
Posts |
|
Appreciate
0
|
03-24-2014, 07:08 PM | #5 |
Private
6
Rep 65
Posts |
I am a little curious as to how sensitive this system is because there is a 6 psi difference (32 front, 38 rear) in air pressure based on the recommended tire pressures. How much off does the tire pressure have to be before the system picks it up.
As far as sticking more money into more TPMS sensors for winter tires why bother. I just pull the fuse on the TPMS system and bingo, no issues. Granted there is a little yellow icon that stays lit but it is not annoying, it is small and out of the way in the dash readout. And how long does one really leave the winter tires on...3 months, maybe 4 during a bad winter. It isn't worth it in my estimate. |
Appreciate
0
|
03-24-2014, 08:02 PM | #6 |
First Lieutenant
44
Rep 336
Posts |
|
Appreciate
0
|
03-24-2014, 08:06 PM | #7 | |
First Lieutenant
44
Rep 336
Posts |
Quote:
What is the reason for pulling the fuse if the light remains lit? Please don't tell me there's a relentless chime... Moon |
|
Appreciate
0
|
03-24-2014, 08:55 PM | #8 |
First Lieutenant
11
Rep 334
Posts |
My '13 has sensors and I ordered additional sensors when I bought my "winter" wheels/tires.
I wouldn't disable the TPMS under any circumstances. It has warned me of a low tire on two occasions where I'm certain that I would have damaged/destroyed the affected tire(on a rather long interstate trip) had I driven on it for a prolonged period of time...once with runflats, once without. Not to mention the danger to myself and others had the tire become hot and come apart. |
Appreciate
0
|
03-24-2014, 09:52 PM | #9 |
Lieutenant Colonel
658
Rep 1,922
Posts
Drives: 2011 e91
Join Date: Jan 2013
Location: Calgary, AB, Canada
|
The reason the guide says differently is because it's written for the entire world, not just Murica. All U.S. spec cars have the tpms built into the stems. Period.
Also, if you remove the fuse to disable the system I can only imagine the legal ramifications which would come about if you ever happened to injure somebody in a collision caused by a loss in tire pressure. Murica is in love with suing people.
__________________
2011 E91
2016 M2 - Sold 2014 X1 - Sold 2002 Land Rover Discovery II - 3" lift & 33s |
Appreciate
0
|
03-24-2014, 10:53 PM | #10 | |
Private
6
Rep 65
Posts |
Quote:
You've been watching too many American movies. Get a grip. |
|
Appreciate
0
|
03-25-2014, 09:39 AM | #11 |
Lieutenant
35
Rep 485
Posts |
I bought a new 07 RX8 with nicer lighter Enkei GF-1 wheels modded by the dealer.
Nobody tried to put sensors in the wheel and I've always had the light which I don't mind. I also take it to sports car tracks and run high performance tires. Those kind of tires have thicker carcass. I've never had a flat in that kind of tire, but have found worn out nails when replacing worn tire. Tires not speed rated like All season get punctured easier. |
Appreciate
0
|
03-25-2014, 10:44 AM | #12 | |
Major General
4457
Rep 9,160
Posts |
Quote:
I had a rear blowout with a Toyo T1R that I caught quickly and didn't shred the rear fender or eat a guardrail, but to think that good tires save you from flats or other issues is just bunk, akin to thinking that a more expensive car should be safer than a cheaper car, or not get flats. Buy some TPMS sensors folks, TireRack sells them for $40/ea. If you're buying good tires, a BMW, premium fuel and paying your insurance, why not maintain a simple safety device that costs you very little and provides a small amount of safety? You can also move them between wheels if you really don't want to buy a second set. |
|
Appreciate
0
|
03-25-2014, 11:17 AM | #13 |
Lieutenant
35
Rep 485
Posts |
Red Bread,
Maybe my article seemed a little fluffy to you, but I used to sell and adjust tires so I do know a little about tire failures. Speed rated radiaL tires usually have soft sidewalls , but tougher belts. Why do you think that some tires are rated to 168+ mph for tread separation? I've had cheap tires that would separate when I tried to run 40 psi. I also had a H rated 130mph tire go soft into a turn once at 100 mph because of bad tire stem. Stems fixed, tire reused for a few years and worn out. There is a wide variation in tire quality, and wide variation in how people drive cars. TPMS is a great safety device, and I wouldn't defeat it myself, but I track my cars and can feel something off with the tires or suspension. |
Appreciate
0
|
03-25-2014, 11:24 AM | #14 |
Major General
4457
Rep 9,160
Posts |
Agreed, I just replaced an awful set of H rater Kumhos on my daily with V rated Michelins. Using better tires is great, but I get so sick of hearing how all season tires are the devil. Maybe I overreacted to that, apologies if so.
I track quite a bit too and have a good sense of what my tires are up to, but my wife panics if the TPMS light comes on and waits until I "fix" it. I'm okay with that. |
Appreciate
0
|
03-25-2014, 11:43 AM | #15 | |
Lieutenant
35
Rep 485
Posts |
Quote:
I've been autoxing since 1973 and just want to drive at HPDE without the "minder" in the car for about 4 20 minute sessions. That first day I had a Lambo in my mirror every 30 seconds and had no problem. I want to drive without the hand wringing. I did just get back from Arroyo Seco Raceway in Deming NM where they let us go and timed us as a super lap. Sorry to OP for the hijack. |
|
Appreciate
0
|
03-25-2014, 01:01 PM | #16 | ||
Private First Class
5
Rep 109
Posts |
Quote:
Quote:
http://www.oewheelsllc.com/Home_3?se...1#.UzHEB-Mo6M8 |
||
Appreciate
0
|
03-25-2014, 01:30 PM | #17 |
Lieutenant
128
Rep 545
Posts
Drives: x3 m40i
Join Date: Feb 2014
Location: Vancouver,BC
|
Can you install real tpms sensors on the Canadian version that comes without it?
|
Appreciate
0
|
03-25-2014, 02:46 PM | #18 |
Private First Class
5
Rep 109
Posts |
|
Appreciate
0
|
03-25-2014, 07:21 PM | #19 |
First Lieutenant
44
Rep 336
Posts |
If the sensors are down to $40@, I may well go with them. Last time I was making this decision, they were more like $90.
What must you do when you change sets of tires to enable the system? Moon |
Appreciate
0
|
03-26-2014, 08:12 AM | #20 | |
Private First Class
5
Rep 109
Posts |
Quote:
If the TPMS transmitter in the tire is the same 433 MHz frequency the receiver is on the X1, then when you swap tires, you go to the TPMS screen and reset the sensors. Last edited by fjrmann; 03-26-2014 at 11:58 AM.. |
|
Appreciate
0
|
03-26-2014, 10:48 AM | #21 |
Private
6
Rep 65
Posts |
|
Appreciate
0
|
03-26-2014, 11:20 AM | #22 |
Major General
4457
Rep 9,160
Posts |
|
Appreciate
0
|
Post Reply |
Bookmarks |
|
|