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You know same as you know with non RFT for decades. You CHECK your tire pressure occasionally.

When I've gotten nails I've noticed before they were down more than 2-3 # without exception.

TPMS is a crutch it's definitely not needed. It's not needed with RFT it's not needed with non RFT it's just plain not needed. If you can't feel a tire pulling sideways when it's low 4-5# that's on you. It's obvious.
 

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You know same as you know with non RFT for decades. You CHECK your tire pressure occasionally.

When I've gotten nails I've noticed before they were down more than 2-3 # without exception.

TPMS is a crutch it's definitely not needed. It's not needed with RFT it's not needed with non RFT it's just plain not needed. If you can't feel a tire pulling sideways when it's low 4-5# that's on you. It's obvious.
I say you argue your case in peer reviewed paper as you it seems everyone is wrong but you.


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Same both ways. You argue your point without practice. I argue mine with roughly 100,000 miles off driving experience. 5-6 nails caught before going flat a couple examples of tires getting destroyed but doing their job.

I never had TPMS never needed it. Nobody really "needs it" you just need to be diligent with tire maintenance.

There are advantages of tpms but that doesn't make it a requirement.
 

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It's a requirement that new cars are sold with TPMS.

If the tpms is non functional do to for example, installing incompatible wheels, it's a requirement that the error light stays lit on the dashboard indicating that the tpms is not operational.


Not required.

To be clear my current situation is non RFT with TPMS and wife's car has non RFT and non operational TPMS we need to get her car in to get the new TPMS installed.

I have nothing against TPMS I'm just explaining that the world got away without it for over a century and it's not needed except that drivers by in large are idiots that never check their tire pressure.

The tpms on e70 is total shit doesn't tell you pressure or which tire is a problem just "there is a problem". I'd rather just check myself than have such a shit design.
 

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It is my understanding that TPMS were made mandatory for run-flats because the extra-stiff sidewall made it especially difficult to notice loss of air pressure.

As I recall, a fella in my Corvette forum said he drove a couple hundred miles at highway speeds not knowing his tire had no air in it. His TPMS was already non-functional so he got no indication of a change.
 

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It 226k miles of BMW-ing (verb: to drive a BMW), I only had one warning, and that was with the FTM on my E46 M3, and that was because I had two nails in a tire.

The FTM's detected low pressure by comparing the relative speeds of the wheels using the ABS sensors. I read that later version also added the driveshaft speed to the calculations to detect when all four tires were low. Somebody had to write the FTM software, but the second and subsequent copies of that software were free. The only additional hardware needed was a FTM warning light and the reset button. FTM cost less than $1 per car. TPMS costs the manufacturer hundreds of dollars costs the consumer hundreds of dollars when the TPMS sensors wear out and need to be replaced. F10 5 Series only had TPMS standard in the US and Canada. In Europe and elsewhere, they still used FTM as standard and TPMS as an option.
 

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It is my understanding that TPMS were made mandatory for run-flats because the extra-stiff sidewall made it especially difficult to notice loss of air pressure.

As I recall, a fella in my Corvette forum said he drove a couple hundred miles at highway speeds not knowing his tire had no air in it. His TPMS was already non-functional so he got no indication of a change.
I'm not aware of a tie between rft and tpms. Tpms is required on all cars.

I noticed loss of tire pressure in a rear tire in deep snow so perhaps it's just a case of not being in tune with your car.

In any event, you don't need tpms to know if your tire is flat. I have always been able to tell when a tire lost 5# due to a nail puncture etc.

I'm not saying TPMS is bad I'm saying it's "not all that". One more overly complicated thing that can and will break and not do its job. One more reason for a driver to not take responsibility for maintenance of their tires.

On my new to me '11 X5, the tire pressure was "all over the place" when I picked it up (27-32 psi) (supposed to be 32 front 36 rear), and no dash warning. Epic fail. Can't trust it so what's the point?
 

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Federal Motor Vehicle Safety Standard 138 is codified as 49 CFR § 571.138 - Standard No. 138; Tire pressure monitoring systems.

49 CFR Subpart B - Federal Motor Vehicle Safety Standards

  • The list of about 70 standards.
 

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A "standard" does not a requirement make. More of a "rule that can be broken".

The question (unanswered at this point) is there some requirement connecting RFT and tpms.

I realize I'm coming off contentious but that's simply me fighting back against people claiming facts not reality based. Prove me wrong with actual facts please not conjecture.

I've had plenty of low tire situations the majority of which were non eventful and at least 90% with no TPMS. TPMS is just a tool it's not a magical cure and yes it was wise for "the powers that be" to get them onto everybody's car because people says terrible at car maintenance.

Before getting all "high and mighty" can you answer in the positive on any of these:

Detect a leaking tire from there air squeak before it's more than 3# low

Notice a screw in a tire from the tap tap while driving before any significant pressure loss

Notice low tire pressure from steering input changing.

Notice a screw in the tire before any loss of pressure just from regular observation

Notice loss of rear end stability from loss of tire pressure.

All those things should be obvious to any driver worth their weight in salt. The fact that not 10% of people qualify is why we have TPMS.

My understanding legally is that you can choose to ignore a tpms light on the dashboard just as you can choose to ignore a check engine light. It's guidance not a hard fast limit. This is without regard to the type of tire.

A Mfg has to follow the rules which say when three car is initially sold it must have functional TPMS. (it clearly can be really shitty TPMS like e70 has), but has to let to know when "a problem" exists not telling you what that problem is. Sorry not sorry that's total shit BMW.
 

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I remember tire manufacturers and tire stores requiring aftermarket TPMS systems before selling somebody RFT's. That was on the advice of engineers and lawyers.
 

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A "standard" does not a requirement make. More of a "rule that can be broken".

The question (unanswered at this point) is there some requirement connecting RFT and tpms.

I realize I'm coming off contentious but that's simply me fighting back against people claiming facts not reality based. Prove me wrong with actual facts please not conjecture.
I am “all high and mighty.”.

I will allow the student to learn (possibly the hard way) about enforcement of federal regulations and FMVSS.
 

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Enforce exactly what? I'm not a car manufacturer. The rules literally don't apply to me. If I am wrong show me where the consumer is responsible to make sure tpms is functional. I'm not disputing if it's a good idea, I'm just sticking with facts only.

Fact or fiction; you must have (working) TPMS if you have RFT.

Fact or fiction; you must have (working) TPMS ever on a car you didn't build.

Spoiler alert: fiction on both.

I'm not saying that's the best answer just saying that's the facts. (prove me wrong).

The legal code referenced above it applies to the manufacturer of the car. It is illegal to sell a car for the first time without working TPMS. I'm ok with that and behind it. People are idiots in general and clearly need that kind of hand holding. Before TPMS, most tires on the road were seriously under inflated. I test my tires weekly and spot test for problems more frequently but that's not usual.
 

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Same both ways. You argue your point without practice. I argue mine with roughly 100,000 miles off driving experience. 5-6 nails caught before going flat a couple examples of tires getting destroyed but doing their job.

I never had TPMS never needed it. Nobody really "needs it" you just need to be diligent with tire maintenance.

There are advantages of tpms but that doesn't make it a requirement.
I argue what is established practice in industry. Your “argument” is contrary to establish facts in industry. Don’t spin this as my opinion. Check your RFT, you have warning there. Warning there is obviously for a reason.


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It's a requirement that new cars are sold with TPMS.

If the tpms is non functional do to for example, installing incompatible wheels, it's a requirement that the error light stays lit on the dashboard indicating that the tpms is not operational.


Not required.

To be clear my current situation is non RFT with TPMS and wife's car has non RFT and non operational TPMS we need to get her car in to get the new TPMS installed.

I have nothing against TPMS I'm just explaining that the world got away without it for over a century and it's not needed except that drivers by in large are idiots that never check their tire pressure.

The tpms on e70 is total shit doesn't tell you pressure or which tire is a problem just "there is a problem". I'd rather just check myself than have such a shit design.
It is requirement.
Problem is enforcement. If you lived in Europe or some US states you wouldn’t be able to pass pre registration inspection with faulty TPMS.
Also TPMS on BMW are not shit. They can tell psi, but your particular vehicle doesn’t have that package. You obviously never had Asian or American vehicles with TPMS where switch from summer to winter tires always requires TPMS registration etc.


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It 226k miles of BMW-ing (verb: to drive a BMW), I only had one warning, and that was with the FTM on my E46 M3, and that was because I had two nails in a tire.

The FTM's detected low pressure by comparing the relative speeds of the wheels using the ABS sensors. I read that later version also added the driveshaft speed to the calculations to detect when all four tires were low. Somebody had to write the FTM software, but the second and subsequent copies of that software were free. The only additional hardware needed was a FTM warning light and the reset button. FTM cost less than $1 per car. TPMS costs the manufacturer hundreds of dollars costs the consumer hundreds of dollars when the TPMS sensors wear out and need to be replaced. F10 5 Series only had TPMS standard in the US and Canada. In Europe and elsewhere, they still used FTM as standard and TPMS as an option.
You can easily code FTM. It is already there. Takes 30sec.


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It is requirement.
Problem is enforcement. If you lived in Europe or some US states you wouldn’t be able to pass pre registration inspection with faulty TPMS.
Also TPMS on BMW are not shit. They can tell psi, but your particular vehicle doesn’t have that package. You obviously never had Asian or American vehicles with TPMS where switch from summer to winter tires always requires TPMS registration etc.


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Knows internally but doesn't tell me that's even worse. Total shit design. I just know that twice TPMS on wife's e70 came on alerting me there was a Problem and lit up all tires.

Spoiler alert there was no problem. It was just cold outside. All the tires were a little low zero tires were low enough to warrant an error message most definitely not 25% low on one tire the system is shit.

They didn't take ambient temperature into account in the programming. The alert came on about 90% of initial pressure when all tires were about the same. Terrible programming shit design. Every other car with TPMS does a better job. Not sure why I bothered getting new sensors I'm better off just measuring tire pressure or getting wife the color coded valve caps.
 

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Knows internally but doesn't tell me that's even worse. Total shit design. I just know that twice TPMS on wife's e70 came on alerting me there was a Problem and lit up all tires.

Spoiler alert there was no problem. It was just cold outside. All the tires were a little low zero tires were low enough to warrant an error message most definitely not 25% low on one tire the system is shit.

They didn't take ambient temperature into account in the programming. The alert came on about 90% of initial pressure when all tires were about the same. Terrible programming shit design. Every other car with TPMS does a better job. Not sure why I bothered getting new sensors I'm better off just measuring tire pressure or getting wife the color coded valve caps.
I read somewhere TPMS's give a low-pressure alert at about 20% below the whatever the pressure was when you reset the system. At one time, pressure display was only activated on M cars. Some country made pressure displays mandatory, so BMW just did it on all the cars. Depending on the age of the car, you can code the pressures to be displayed.

They do account for temperature. They compare the tire air temperature to the ambient temperature and adjust the recommended pressures accordingly.

Some people add 10% pressure, baseline the TPMS, and then take the 10% added pressure back out. That gives the TPMS a ~10% below baseline threshold for giving an alarm instead of the normal 20%.
 

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I need to get a coding setup ; I noticed my '11 isn't as obtrusive as wife's '12 where you have to press the "ok" button every time you start the car.
 
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