[Doug Huffman]

 

[Doug Huffman]

https://www.nhtsa.gov/sites/nhtsa.gov/files/0701tirepressure.pdf

 

[andrewwynn]

The charts do show the disaster of the situation that brought about TPMS: the percentage of people that both "visually" check their tires combined with using the max number on the tire not the door jamb is very disturbing.

 

[edycol]

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.

TPMS should NOT take into consideration pressure drop due to cold weather. Reason is that you lost pressure. It is not like it is there but reading is wrong, it is that you lost it!
Tire engineers I knew from days when I worked as test drivers always say 5psi over cold pressure recommendation before cold weather hits.
If TPMS is programmed to not worn you about it, you will have low pressure. If recommended pressure is 38psi and you set it up at 70 degrees weather, at 0 degrees your tire press is in mid 20’s. So what do you want? System to neglect that low pressure?
Also, there are E70’s with actual number readings. Yours doesn’t have that.
But what confuses me is that you want to rely on readings but at the same time you are all about visual inspection?
To me you are yelling at the cloud.


Sent from my iPhone using Tapatalk

 

[edycol]

The charts do show the disaster of the situation that brought about TPMS: the percentage of people that both "visually" check their tires combined with using the max number on the tire not the door jamb is very disturbing.

But you also want actual readings so you don’t have to inspect it?
Life doesn’t work like that. You could have kid with 105f fever at 2am like I did. Are you going to check pressure? If i had flat or low pressure,, TPMS would tell me, and I would take another car.
Also, before we didn’t have child sears, and air bags, and seat belts, and ABS, and ESP, etc. So should we get rid of it?


Sent from my iPhone using Tapatalk

 

[andrewwynn]

You read my comments about visual inspection at best very wrong.

Visual inspection has caught a dozen nail: screw type damage earlier than TPMS aka "the crutch" in my experience.
TPMS came about due to overall laziness and ignorance of drivers.

It wasn't necessary 100 years ago, it's not necessary today. It's a requirement do to the average person having an average IQ.


Sent from my iPhone using Tapatalk Pro

 

[andrewwynn]

But you also want actual readings so you don’t have to inspect it?
Life doesn’t work like that. You could have kid with 105f fever at 2am like I did. Are you going to check pressure? If i had flat or low pressure,, TPMS would tell me, and I would take another car.
Also, before we didn’t have child sears, and air bags, and seat belts, and ABS, and ESP, etc. So should we get rid of it?


Sent from my iPhone using Tapatalk

I never said TPMS is bad or should be avoided I said the particular implementation on e70 is total shit and I'm better off just measuring the pressure myself.

Regarding the hypothetical drive to ER with child I would drive off and unless a tire is more than 10# low I will get there and diagnose why the car was pulling funny before heading home.

aBS is responsible for plenty of crashes. The best way to describe this is that it adds 30% to your stopping distance. You can steer Soo you get to choose what you want to hit, rather than avoid hitting whatever in the first place. There are always trade offs.

I'm not anti TPMS I'm anti moronic.

TPMS that alerts me of a non problem (29# on 4 tires due to ambient is not a problem. It's not near the cut off required by the code and it's moronic).

TPMS with values is a different story all together.

And still: the question of the thread topic nope addressed: RFT rims? Non RFT tires? I've gone both ways never caused a problem either way.

 

[edycol]

I never said TPMS is bad or should be avoided I said the particular implementation on e70 is total shit and I'm better off just measuring the pressure myself.

Regarding the hypothetical drive to ER with child I would drive off and unless a tire is more than 10# low I will get there and diagnose why the car was pulling funny before heading home.

aBS is responsible for plenty of crashes. The best way to describe this is that it adds 30% to your stopping distance. You can steer Soo you get to choose what you want to hit, rather than avoid hitting whatever in the first place. There are always trade offs.

I'm not anti TPMS I'm anti moronic.

TPMS that alerts me of a non problem (29# on 4 tires due to ambient is not a problem. It's not near the cut off required by the code and it's moronic).

TPMS with values is a different story all together.

And still: the question of the thread topic nope addressed: RFT rims? Non RFT tires? I've gone both ways never caused a problem either way.

E70 implementation is not shit. It is fine.
TPMS is not there to replace visual inspection. That is not intention of TPMS. TPMS should alert you of low pressure or puncture, not chasing nails for you or wear etc.
You have a problem with people not TPMS. To me people don’t behave like you want them, so it pisses you off (bcs. you are doing everything right) and TPMS is just another way to be lazy.
Don’t be like them. TPMS is fine. Check your pressure values using manual pressure monitor. I mean, you are all about that, right?


As for ABS, there is solution for you. Take out ABS fuse and code out ABS warning. And there you go, 30% shorter braking distance.

Sent from my iPhone using Tapatalk

 

[Autoputzer]

https://www.nhtsa.gov/sites/nhtsa.gov/files/0701tirepressure.pdf

That's interesting.

Americans are bad about checking their tires. Obama once said that if people would keep their tires pumped up it would save more oil than we'd get by drilling in ANWR. Car and Driver debunked that, but is an exaggeration instead of being totally false.

I have to pull my cars out of the garage to check the tires. I do it in the morning. The (other) geezers out getting in their 10,000 steps always ask "You got a flat tire?"

 

[edycol]

That's interesting.

Americans are bad about checking their tires. Obama once said that if people would keep their tires pumped up it would save more oil than we'd get by drilling in ANWR. Car and Driver debunked that, but is an exaggeration instead of being totally false.

I have to pull my cars out of the garage to check the tires. I do it in the morning. The (other) geezers out getting in their 10,000 steps always ask "You got a flat tire?"

Absolutely worse thing for tires is loss of pressure, even slight one.
Michelin once in campaign on this issue said that people are wasting money on high quality tires hoping to improve handling if they keep their pressure 2psi or lower than recommended. They said they could get cheapest tires then. That is how much influences handling.
But, it is not just American thing. In Europe is same thing, and elsewhere. And more and more people use cars as an appliance. I changed battery two days ago for my neighbor, deputy Sheriff, retired sergeant major. He doesn’t know how to replace battery in his Chevy truck (as simple as it gets).
I mean, in 50’s in manual you had how to adjust valves. Now you have warning not to drink battery fluid .


Sent from my iPhone using Tapatalk

 

[Autoputzer]

There was somebody on BF a few months ago who got a low coolant message on their new BMW. So, they had it towed to the BMW dealership.

 

[andrewwynn]

E70 implementation is not shit. It is fine.
TPMS is not there to replace visual inspection. That is not intention of TPMS. TPMS should alert you of low pressure or puncture, not chasing nails for you or wear etc.
You have a problem with people not TPMS. To me people don’t behave like you want them, so it pisses you off (bcs. you are doing everything right) and TPMS is just another way to be lazy.
Don’t be like them. TPMS is fine. Check your pressure values using manual pressure monitor. I mean, you are all about that, right?


As for ABS, there is solution for you. Take out ABS fuse and code out ABS warning. And there you go, 30% shorter braking distance.

Sent from my iPhone using Tapatalk

Or just don't jab the pedal to the floor as exclusively taught. Abs /DSC is a marvel of technology it just had a trade off of longer stopping distance which is never taught to three people being indoctrinated to slam the pedal to the floor and let the magic happen.

I rather find the highest braking force without skidding the tires but when I hit something extra slippery I get a bit of abs just not the whole time.

You won't convince me otherwise on e70 shit tpms. Twice it sent me to air up when not needed. There conditions set by the rules (one tire low by 20-25% or all tires low by some amount) was not met so it failed at its one job.

Maybe was related to the old sensors and when I get the new ones installed won't be so wonky but until I can code them to be less moronic they will still be moronic.

 

[andrewwynn]

As for ABS, there is solution for you. Take out ABS fuse and code out ABS warning. And there you go, 30% shorter braking distance.

Sent from my iPhone using Tapatalk

FYI the comment to pull the fuse is just being an ass we don't need that at xo.


Sent from my iPhone using Tapatalk Pro

 

[Autoputzer]

The first suspect in "wonky" TPMS behavior is "wonky" pressure values at the last TPMS reset. TPMS resets should only be done when the car is completely cooled off, before sunlight hits any of the tires, and with the pressures physically adjusted with a quality pressure gauge (not a pencil gauge). The car probably then needs to be driven to complete the reset. If you don't do all this before a TPMS reset, you are almost guaranteeing "wonky" TPMS behavior.

E70's have been out of production since 2013. TPMS sensors don't last forever. Their life depends on mileage and the vehicle's run time. When I bought tires the last time (71k miles, seven years, 2110 hours of run time), I had them replace the TPMS sensors. That should make me good to go on TPMS sensors for at least another 71k miles, seven years, and 2100 hours of run time.

I record and reset my MPG and average MPH (ΦMPH) when I refuel. From ΦMPH and the odometer reading, I can calculate the run time on each tank of gas and therefore since new.

 

[edycol]

FYI the comment to pull the fuse is just being an ass we don't need that at xo.


Sent from my iPhone using Tapatalk Pro

Well, I found solution for you. I would definitely do that if I knew it would gain 30%.
But then, I was on Continental test track when they test ABS units, so I know it is not true.


Sent from my iPhone using Tapatalk

 

[ard]

you don't want to just bop into Discount Tire and have them install a new tire to go along with your other 3 tires sporting 7/32" of tread.

AM.

FWIW...years ago I did a bit of an analysis on this. I looked at the range of staggered tires BMW shipped all E70s, and found the largest variance from front to rear. I used this as 'the maximum allowable limit BMW engineers will permit' (autoputz will quote a british BMW TIS entry for the 6 series that says something else. I figured if they ship cars with it, that should have precedence over a self-serving 'tire sales' fabrication)

Using this spec, I computed the revs/mile for a new tire and a tire with 50% tread. A 50% tread 'mismatch' is just about the same mismatch as the one BMW had shipped some E70s with.

Short point? You dont need to have anyone shave tires down to match the other 3 if they are 7/32"

I'm not aware of a tie between rft and tpms. Tpms is required on all cars.

Not sure if this has been said, but (as I recall) the TPMS that uses rotational speed is NOT acceptable for run flats as they dont (may not?) chage diameter enough to trip an error. So tires with RFTs need an actual PRESSURE monitor.

 

[andrewwynn]

The BMW workshop manual lists a 1% maximum allowable difference between tires to avoid transfer case damage, on the x drive transfer case. I don't have the published figure for the non x drive transfer case. 1% works out to about 7 revs/mile, so that is their hard limit.

I've found 1% between tires and 3% difference in start to finish tire size but I don't know how the car is supposed to know this if all the tires shrink the same amount.

 

[Autoputzer]

That's not a British-version TIS for a 6 Series. TIS is translated from German into English, not German translated into American.

That spec' for tread depth differences is linked from the TIS sections for all platforms. It's not just in the 6 Series section of TIS. It just happened to be linked from the 6 Series section when somebody did a screen shot. That's how IETM's (interactive electronic technical manuals) work.

The closer the average rolling diameter of the front and rear tires are to each other, the less the constant scrubbing of the clutches in the xDrive transfer case will be. Zero is optimal. BMW somewhat arbitrarily set the tread depth difference at 2mm (2.5/32"). In addition to tread depths, you would also have to account for tire sidewall deformation to achieve zero clutch scrubbing, and sidewall deformation is a function of the tire(s), axle weights, and tire pressures.

Because of that tire sidewall deformation thing, I use the same pressures front and rear on Frau Putzer's X3 xDrive. With BMW's ~50/50 weight distribution that would keep the sidewall deformations close to even front to rear. With regular tire rotation, my front and rear average tread depths are pretty much dead even (within 0.2/32").

Aardvark is right in that some staggered set-ups have different nominal rolling diameters front and rear. The moral of this story is that staggered set-ups and smart AWD are a bad combination.

 

[Attacking Mid]

If maximum performance is your objective, an occasional TC replacement is part of the cost I guess. I can imagine BMW's decision to put different sized wheels on the car came down to: will it (TC) survive 50K miles? Sorta like the lifetime fluids issue and 15K mi. OCI. Since I'm the kind of guy who drives 'em to 200K+, I would really like to keep that TC alive as long as possible, so I try to keep my tires as even as reasonably possible. I've never had a tire shaved, but I have purchased used tires online to match my existing tires, though that's getting to be tougher to do these days as the tire industry keeps shortening the deemed serviceable age for tires.

AM.

 

[Autoputzer]

If maximum performance is your objective, an occasional TC replacement is part of the cost I guess. I can imagine BMW's decision to put different sized wheels on the car came down to: will it (TC) survive 50K miles? Sorta like the lifetime fluids issue and 15K mi. OCI. Since I'm the kind of guy who drives 'em to 200K+, I would really like to keep that TC alive as long as possible, so I try to keep my tires as even as reasonably possible. I've never had a tire shaved, but I have purchased used tires online to match my existing tires, though that's getting to be tougher to do these days as the tire industry keeps shortening the deemed serviceable age for tires.

AM.

Staggered set-ups are mostly for cosmetics. BMW product liability lawyers also like them because it biases the car toward understeer. Juries tend to blame a car going off a cliff backwards on the car but blame a car going off a cliff forward on the driver.

People who sell tires like staggered set-ups too, since people often relace all four tires before the front tires are anywhere near being worn out. I'm on a crusade to get at least 60k miles out of the square set-up, non-run-flat, OE tires on Frau Putzer's X3 xDrive 30i.