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      10-07-2020, 04:15 PM   #23
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And please don't try to wiggle out of your claim


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      10-07-2020, 09:12 PM   #24
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Solid point there.
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      10-07-2020, 09:33 PM   #25
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Tires rather than brakes are often the biggest factor in stopping distance. If you can lock them with your brakes, there's no difference between the actual brakes. How well they handle heat from repeated use could easily be different, as can the amount of pressure required to lock those brakes, but that also depends on the actual pads used. How much pedal travel and the feel can differ between calipers and pads, too.
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      10-08-2020, 02:16 PM   #26
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Comparing to a non specified control group is like comparing acceleration of a 118i vs a 850i and saying the 850 is a faster car.

It doesn't mean anything, just that they were able to find brakes that actually performed worse than what they are trying to sell. They did a good job on that.

Because of you perfect scientific replies in the last's post. I presume you are a engineer? I wondered why you would take such a worthless test to prove your point.
I disagree that it's a worthless test - bias does not necessarily make a test worthless. Anyway - here's a very scientific experiment (scroll down to pages 59-62): https://www.michigan.gov/documents/m...n_337522_7.pdf

Can we put this to rest now?
That is a more scientific article. A shame they didn't formulate a conclusion an a abstract would have been nice in stead of going through it.

I think we can conclude from this that they have really bad standard brakes on some US produced police cars that is for sure.

The differences between the different brake pads are below 4% even at 125 mph to 0 testing. Doesn't look significant to me and there is no statistical analysis. The differences in the graph look bigger than they are because of the well chosen numbers on the y axis.
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      10-08-2020, 02:25 PM   #27
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The M sport package looks so much better than the x-line. I would recommend getting the M sport, just for the M sport look. The brakes are really not needed. I prefer the standard brakes as they are less dusty and just a tad bit smoother when cold. Yes, the feel is better with the M sport brakes but the standard brakes are very effective too, make less dust, and cost less to replace.
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      10-09-2020, 06:39 PM   #28
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Originally Posted by X5 45e View Post
That is a more scientific article. A shame they didn't formulate a conclusion an a abstract would have been nice in stead of going through it.

I think we can conclude from this that they have really bad standard brakes on some US produced police cars that is for sure.

The differences between the different brake pads are below 4% even at 125 mph to 0 testing. Doesn't look significant to me and there is no statistical analysis. The differences in the graph look bigger than they are because of the well chosen numbers on the y axis.
They did multiple runs and have the mean and stdev right there in addition to the raw data.

Those standard brakes may be bad, but if anyone thinks they can't lock the wheels I have a bridge I'd like to sell.
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      10-09-2020, 07:22 PM   #29
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The bigger thing on stopping distance is the tire compound. I do not know what tires BMW puts on the vehicles with M sport, but it may be a higher performance tire. The feel of the brake can easily change as can how much pressure it takes to lock the wheel up, but once the wheel is locked, it's all about friction between the tire and the road. To get a valid comparison, you need the same tires and the vehicles need to be the same weight. The 45e is quite a bit heavier than the other versions, and it will take longer to stop even if the tires are the same compared to one of the other versions.
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      10-09-2020, 09:36 PM   #30
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Quote:
Originally Posted by Noneya View Post
Quote:
Originally Posted by X5 45e View Post
That is a more scientific article. A shame they didn't formulate a conclusion an a abstract would have been nice in stead of going through it.

I think we can conclude from this that they have really bad standard brakes on some US produced police cars that is for sure.

The differences between the different brake pads are below 4% even at 125 mph to 0 testing. Doesn't look significant to me and there is no statistical analysis. The differences in the graph look bigger than they are because of the well chosen numbers on the y axis.
They did multiple runs and have the mean and stdev right there in addition to the raw data.

Those standard brakes may be bad, but if anyone thinks they can't lock the wheels I have a bridge I'd like to sell.
It doesn't say if the valuables are significantly different when comparing the different brake pads on a single car.

There is only one outlier in CVP1 (FDP) that is really performing worse.

Statics aside and just looking at the graph. The only higher quality car tested in the Dodge Charger and the OE pads have the same results as the after market pads.

I think this article is better than the flyer you found first, good job. But they didn't formulate a hypothesis and conclusion nor significance.

And this doesn't say anything about the stopping quality of the standard BMW brakes in a single emergency brake event compared to the M brakes when both are at normal working temperature. This is what we were discussing: do the m brakes reduce the stopping distance significantly compared to the standard brakes when not tracking the car. So at normal working temperatures and speeds.

And like mentioned, other variables might be just as important. Type and quality of tires, reaction speed. Having the driving assistant pro for example will assist in applying maximal braking power if needed.
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      10-09-2020, 11:39 PM   #31
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Also, not sure why there is constant discussion of locking tires for vehicles equipped with always-on ABS and certainly always on during normal daily driving that triggers emergency braking situations. What am I missing?
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      10-10-2020, 12:45 AM   #32
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Also, not sure why there is constant discussion of locking tires for vehicles equipped with always-on ABS and certainly always on during normal daily driving that triggers emergency braking situations. What am I missing?
Because brake performance in terms of every day stopping distance is more/less between the time someone slams the brake pedal and when the wheels lock, or would lock if it weren't for the ABS, i.e., just before the ABS kicks in and takes over. But if your brakes can't quickly lock the wheels then you won't be stopping as fast as you could. (or until something else stops you!)

For example, if your brakes aren't ever strong enough to lock the wheels then no ABS and trouble!

Where big brakes come into play is during high heat situations when brake "fade" starts happening, i.e, the brakes lose their ability to turn kinetic energy into heat since the brakes are overheating. The ///M brakes are built to resist fade in heavy duty use scenarios, i.e., when the brakes are prone to overheating like for track use or riding the brakes down a 15,000 foot mountain while towing 5,000 lbs. In that scenario the ///M brakes would outperform the standards as the standard would start to fade faster and lose their ability to lock the wheel.

An analogy might be a contest to see who can press the "N" key the fastest; let's say my index finger is twice as strong as yours ... it might seem like I would win, but since your index finger is already plenty strong enough to press the N key, my greater strength is meaningless in the single press scenario, ie., the difference between us will be insignificant. However if we had to rapidly press that key as many times as we could, your times would likely start slowing before mine, and eventually you'd fail to press the key before I would.
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Last edited by GrussGott; 10-10-2020 at 01:31 AM..
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      10-10-2020, 01:45 AM   #33
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Also, not sure why there is constant discussion of locking tires for vehicles equipped with always-on ABS and certainly always on during normal daily driving that triggers emergency braking situations. What am I missing?
Because brake performance in terms of every day stopping distance is more/less between the time someone slams the pedal and when the wheels lock, or would lock if it weren't for the ABS, i.e., just before the ABS kicks in and takes over. But if your brakes can't lock the wheels then you won't be stopping as fast as you could.

For example, if your brakes aren't ever strong enough to lock the wheels then no ABS and trouble! (or at least the brakes can't get the wheel close to lock)

Where big brakes come into play is during high heat situations when brake "fade" starts happening, i.e, the brakes lose their ability to turn kinetic energy into heat since the brakes are overheating. The ///M brakes are built to resist fade in heavy duty use scenarios, i.e., when the brakes are prone to overheating like for track use or riding the brakes down a 15,000 foot mountain while towing 5,000 lbs. In that scenario the ///M brakes would outperform the standards as the standard would start to fade faster and lose their ability to lock the wheel.

An analogy might be a contest to see who can press the "N" key the fastest; let's say my index finger is twice as strong as yours ... it might seem like I would win, but since your index finger is plenty strong to press the N key, my greater strength is meaningless in the single press scenario, ie., the difference between us will be insignificant. However if we had to press that key as many times as we could, your times would likely start slowing before mine, and eventually you'd fail to press the key before I would.
Maybe the less strong index would even have a better fine motor function and be faster than the strong index!

If you have the money go for the m sport brakes. And then go to the other thread on the red and blue choice. Good they only have two color options. 😂

Some thoughts to add to the discussion. Larger / heavier wheels also increase the braking distance. And wider tires are better on dry roads but are more prone to aqua planing on wed roads. So for safety reasons in all situations don't go for the largest tires. The looks is another discussion.

I think for safety reasons go for:

Driving assistent pro to reduce reaction time it can regulate braking power when you react to late.

Make sure your tires are in good condition

Don't drink and drive

Take a stop when you feel tired. Those two seconds reacting earlier might be more important.
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      10-10-2020, 03:26 AM   #34
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Originally Posted by bmw_lover1 View Post
Can anyone chime in on whether the M Sport Brakes are worth it for this car?Are they actually worth upgrading to the M Sport line (instead of xLine) and losing the running boards?
Maybe I've already said this, but I'm a fan of the old school x-line look and prefer it over the m-sport look (I also like the running boards)!

FWIW I've had ///M brakes for the last decade on all of my BMWs, and have fried a few sets of brakes in my day ... with that, I have no hesitation getting the standard brakes that come with the x-line. If I wanted the m-sport package I'd for sure get the ///M brakes, but I don't and feel perfectly satisfied with the standards.
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      10-10-2020, 07:27 AM   #35
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Quote:
Originally Posted by X5 45e View Post
It doesn't say if the valuables are significantly different when comparing the different brake pads on a single car.

There is only one outlier in CVP1 (FDP) that is really performing worse.

Statics aside and just looking at the graph. The only higher quality car tested in the Dodge Charger and the OE pads have the same results as the after market pads.

I think this article is better than the flyer you found first, good job. But they didn't formulate a hypothesis and conclusion nor significance.

And this doesn't say anything about the stopping quality of the standard BMW brakes in a single emergency brake event compared to the M brakes when both are at normal working temperature. This is what we were discussing: do the m brakes reduce the stopping distance significantly compared to the standard brakes when not tracking the car. So at normal working temperatures and speeds.

And like mentioned, other variables might be just as important. Type and quality of tires, reaction speed. Having the driving assistant pro for example will assist in applying maximal braking power if needed.
Sorry, but what you wrote is largely word salad. I've been very clear from the very beginning that my disagreement is about the statement "if two brakes can both lock the rotors they will have the same stopping distance". This statement is very clearly proven false in that article unless you believe any of those brakes can't lock the wheels. I don't have anything else to add.
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      10-10-2020, 08:09 AM   #36
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Quote:
Originally Posted by Noneya View Post
Quote:
Originally Posted by X5 45e View Post
It doesn't say if the valuables are significantly different when comparing the different brake pads on a single car.

There is only one outlier in CVP1 (FDP) that is really performing worse.

Statics aside and just looking at the graph. The only higher quality car tested in the Dodge Charger and the OE pads have the same results as the after market pads.

I think this article is better than the flyer you found first, good job. But they didn't formulate a hypothesis and conclusion nor significance.

And this doesn't say anything about the stopping quality of the standard BMW brakes in a single emergency brake event compared to the M brakes when both are at normal working temperature. This is what we were discussing: do the m brakes reduce the stopping distance significantly compared to the standard brakes when not tracking the car. So at normal working temperatures and speeds.

And like mentioned, other variables might be just as important. Type and quality of tires, reaction speed. Having the driving assistant pro for example will assist in applying maximal braking power if needed.
Sorry, but what you wrote is largely word salad. I've been very clear from the very beginning that my disagreement is about the statement "if two brakes can both lock the rotors they will have the same stopping distance". This statement is very clearly proven false in that article unless you believe any of those brakes can't lock the wheels. I don't have anything else to add.
Ok, no problem if you don't understand.
Maybe my English is a part of the problem.

Do you know anything about statistic and defining if differences are significant?

If the differences between the different brake pads is not significant the test is inconclusive.

Like I mention there is only one outlier in one of the tested cars. The other ones are quite similar. I don't know and don't see the statistic analysis with p lesser than 0,05. So scientifically this test is not correct either.

Anyway if you like blue or red brakes buy the m sport brakes. And if you want more safety buy driving assistant pro and good tires.
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      10-10-2020, 08:30 AM   #37
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My colleague has a 45e x line without m brakes. Maybe to finish this discussion we should do a test side by side and see who stops first. Unfortunately he has 19inch summers and me 20 inch. We both have 19 inch winter wheels.

Lots of 45e's here also others with 21 and 22 inch maybe we can even test if wheels size matters.
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      10-10-2020, 02:11 PM   #38
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Noneya

Please provide results from a t-test or similar to back up your claim that a proper statistical analysis has been carried out.

Thanks in advance!
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      10-10-2020, 03:40 PM   #39
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Quote:
Originally Posted by X5 45e View Post
Ok, no problem if you don't understand.
Maybe my English is a part of the problem.

Do you know anything about statistic and defining if differences are significant?

If the differences between the different brake pads is not significant the test is inconclusive.

Like I mention there is only one outlier in one of the tested cars. The other ones are quite similar. I don't know and don't see the statistic analysis with p lesser than 0,05. So scientifically this this is not correct either.

Anyway if you like blue or red brakes buy the m sport brakes. And if you want more safety buy driving assistant pro and good tires.
For the point I've been making all I need to do is to find any two sets that are significantly different. Take columns 7 and 8 on page 61. If it's not immediately obvious to you that the p-value of a t-test is significantly smaller than 0.05 for those 2 samples, then I'm sorry but you have no business talking about p-value.
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      10-10-2020, 03:49 PM   #40
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Quote:
Originally Posted by Noneya View Post
Quote:
Originally Posted by X5 45e View Post
Ok, no problem if you don't understand.
Maybe my English is a part of the problem.

Do you know anything about statistic and defining if differences are significant?

If the differences between the different brake pads is not significant the test is inconclusive.

Like I mention there is only one outlier in one of the tested cars. The other ones are quite similar. I don't know and don't see the statistic analysis with p lesser than 0,05. So scientifically this this is not correct either.

Anyway if you like blue or red brakes buy the m sport brakes. And if you want more safety buy driving assistant pro and good tires.
For the point I've been making all I need to do is to find any two sets that are significantly different. Take columns 7 and 8 on page 61. If it's not immediately obvious to you that the p-value of a t-test is significantly smaller than 0.05 for those 2 samples, then I'm sorry but you have no business talking about p-value.
Haha. Now that's scientific. They look different. I think you should stick to mechanics. You did a good job in that.
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      10-10-2020, 04:20 PM   #41
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Originally Posted by X5 45e View Post
Haha. Now that's scientific. They look different. I think you should stick to mechanics. You did a good job in that.
Sorry, I don't have the desire to explain p-values to amateurs, especially when given amateurs have shown no interest in thinking. Yes, I realize that the above sentence makes it even less likely that you'll think, but alas I truly am really done with this thread. At the very least read a little about standard deviations and p-values, if you manage to understand the point I made, PM me.
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      10-10-2020, 04:22 PM   #42
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Quote:
Originally Posted by Caramel View Post
Noneya

Please provide results from a t-test or similar to back up your claim that a proper statistical analysis has been carried out.

Thanks in advance!
Do it yourself. The data is right there and you can find an online calculator. The answer is obvious from mean and stdev values if you understand what all the above quantities mean (hint: how many standard deviations is p-value of 0.05).
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      10-10-2020, 05:11 PM   #43
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Quote:
Originally Posted by Noneya View Post
Do it yourself. The data is right there and you can find an online calculator. The answer is obvious from mean and stdev values if you understand what all the above quantities mean (hint: how many standard deviations is p-value of 0.05).
If you make a claim, it's your obligation to prove it.

And before you waste your time trying to figure out how many standard deviations you need in difference for two series to be significantly different from each other: It's the difference expressed as a multiple of standard errors(!), not standard deviations that determines the significance level of said difference. Anyway, you might be better of with Welch's t-test for this comparison.

Good luck, let us know what you find
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      10-10-2020, 05:38 PM   #44
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Quote:
Originally Posted by Caramel View Post
If you make a claim, it's your obligation to prove it.

And before you waste your time trying to figure out how many standard deviations you need in difference for two series to be significantly different from each other: It's the difference expressed as a multiple of standard errors(!), not standard deviations that determines the significance level of said difference. Anyway, you might be better of with Welch's t-test for this comparison.

Good luck, let us know what you find
As I said, please don't use fancy words, unless you know what you're talking about.

> t.test(c(138.07, 138.29, 137.62, 138.14, 138.19, 139.01, 141.35, 140.29, 135.05, 138.58), c(144.88, 146.7, 147.73, 145.44, 145.16, 142.06, 140.51, 141.66, 141.52, 145.26))

Welch Two Sample t-test

data: c(138.07, 138.29, 137.62, 138.14, 138.19, 139.01, 141.35, 140.29, 135.05, 138.58) and c(144.88, 146.7, 147.73, 145.44, 145.16, 142.06, 140.51, 141.66, 141.52, 145.26)
t = -6.0057, df = 15.772, p-value = 1.947e-05
alternative hypothesis: true difference in means is not equal to 0
95 percent confidence interval:
-7.623701 -3.642299
sample estimates:
mean of x mean of y
138.459 144.092
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