Are the Tesla Model 3 brakes really worst in class?

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Consumer Reports released their data. Other organizations should be able to recreate testing to see if they get the same results. The part that is odd to me is that on the test stop they got a result that would be considered expected, but then on subsequent tests very bad numbers. I think that is they key to finding the problem if there is one.
 
Mark W said:
Consumer Reports released their data. Other organizations should be able to recreate testing to see if they get the same results. The part that is odd to me is that on the test stop they got a result that would be considered expected, but then on subsequent tests very bad numbers. I think that is they key to finding the problem if there is one.
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Looked at the results, its very strange that the numbers got so much worse after 1 attempt, and with the car not having a lot of miles (normally GM or other big makers will certify with fully worn out pads to get a true worst case scenario for their ratings), I wonder if it is problem with the friction material as well as software. Also something to note, most cars in the class are between 120 to 125, but on the performance model, if Elon keeps his promise (best in class), it needs to beat the 99' of the BMW M3... That is going to take some massive brakes because the car is going to weigh over 4k Lbs. Not sure how Tesla is going to keep the 310 mile range with all that added mass, and especially the unsprung mass of the larger wheels and brakes.

It has been noted in track testing that the brakes wear out quickly, just a few laps on the track on the Model 3, brakes could also be a bit undersigned for the weight of the car?
 
It appears to be a bug in the ABS firmware of the brake controller. CR uses a maximum mash on the brake pedal, engaging the ABS with each stop. Apparently there is a bug that latches or defeats the ABS control logic after the first use.

This will be handled by an OTS update ... no hardware changes or service visit.

Bob Wilson
 
bwilson4web said:
It appears to be a bug in the ABS firmware of the brake controller. CR uses a maximum mash on the brake pedal, engaging the ABS with each stop. Apparently there is a bug that latches or defeats the ABS control logic after the first use.

This will be handled by an OTS update ... no hardware changes or service visit.

Bob Wilson
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It is possible that the software in the ABS system is causing the problem, it is also possible that the braking system is slightly undersized for the weight of the car, and rotors or friction materials cannot handle the heat.

As far as I know the ABS system Tesla uses comes from a 3rd party vendor and cannot be updated OTA, because it is a closed loop system and does not run with Tesla's software, this was talked about in a another forum and Tesla people confirmed this. So it will likely be a least a recall for a refresh, and possibly a hardware recall. I am sure Consumer reports will keep us updated. For the record Edmunds test car had warped rotors, and Car and Driver also had long stopping distances. Skipping a formal test and validation program doesn't pay... Elon should have learned by now.
 
David Green said:
It is possible that the software in the ABS system is causing the problem, it is also possible that the braking system is slightly undersized for the weight of the car, and rotors or friction materials cannot handle the heat.

As far as I know the ABS system Tesla uses comes from a 3rd party vendor and cannot be updated OTA, because it is a closed loop system and does not run with Tesla's software, this was talked about in a another forum and Tesla people confirmed this. So it will likely be a least a recall for a refresh, and possibly a hardware recall. I am sure Consumer reports will keep us updated. For the record Edmunds test car had warped rotors, and Car and Driver also had long stopping distances. Skipping a formal test and validation program doesn't pay... Elon should have learned by now.
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Well fortunately that won't be my problem. Soon enough we'll see if there is a hardware recall or a firmware update.

Bob Wilson
 
Rob R said:
Problem fixed. Can we move on please. Model 3 CR recommended.
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I am not sure we are ready to move on yet. Tesla did improve the stopping distance of the Model 3 from worse then an F150 152' down to 133", but that is still far from best in class.

Elon's Tweet "Looks like this can be fixed with a firmware update. Will be rolling that out in a few days. With further refinement, we can improve braking distance beyond initial specs. Tesla won’t stop until Model 3 has better braking than any remotely comparable car."

I am not sure what he considers remotely comparable, but they always like to compare to the BMW 3 series which stops from 60 in 123' to M3 99' Audi A4 Quattro 104' Alfa Gulia 120' to quad 99' Cadillac ATS 111'- V Model 97' Mercedes C Class 118'- AMG 97'

As you can see Model 3 @ 133', is still by far the worst in class, so Elon has lots of work to do still...
 
David Green said:
. . .
I am not sure what he considers remotely comparable, but they always like to compare to the BMW 3 series which stops from 60 in 123' to M3 99' Audi A4 Quattro 104' Alfa Gulia 120' to quad 99' Cadillac ATS 111'- V Model 97' Mercedes C Class 118'- AMG 97'

As you can see Model 3 @ 133', is still by far the worst in class, so Elon has lots of work to do still...
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Car and Driver reports:
  • 189' - Prius Prime
  • 179' - Model 3 (before fix)
  • 160' - BMW i3
Guess I'm going to die.
https://getyarn.io/yarn-clip/343d708d-ca05-441d-a964-d268edb4e99c#SyaVImjKem.copy

Bob Wilson
 
bwilson4web said:
Car and Driver reports:
  • 189' - Prius Prime
  • 179' - Model 3 (before fix)
  • 160' - BMW i3
Guess I'm going to die.
https://getyarn.io/yarn-clip/343d708d-ca05-441d-a964-d268edb4e99c#SyaVImjKem.copy

Bob Wilson
Click to expand...
Those are your comparisons? and C & D is from 70Mph... But I do not think those are the cars Elon was talking about, Tesla always likes to compare themselves to the entry lux market, Elon did so at the shareholder meetings, so I have so assume those are the competitors he is talking about. BTW to get a Prius prime to 70, did they strap a rocket on the side of it? haha!
 
David Green said:
I am not sure we are ready to move on yet. Tesla did improve the stopping distance of the Model 3 from worse then an F150 152' down to 133", but that is still far from best in class.

Elon's Tweet "Looks like this can be fixed with a firmware update. Will be rolling that out in a few days. With further refinement, we can improve braking distance beyond initial specs. Tesla won’t stop until Model 3 has better braking than any remotely comparable car."

I am not sure what he considers remotely comparable, but they always like to compare to the BMW 3 series which stops from 60 in 123' to M3 99' Audi A4 Quattro 104' Alfa Gulia 120' to quad 99' Cadillac ATS 111'- V Model 97' Mercedes C Class 118'- AMG 97'

As you can see Model 3 @ 133', is still by far the worst in class, so Elon has lots of work to do still...
Click to expand...

Edmunds
Published on Jun 14, 2018

Did Tesla's over-the-air firmware update change the braking distance of our Model 3? Dan Edmunds, director of vehicle testing for Edmunds, heads back to the track with our long-term Model 3 for a second round of brake tests following a firmware update (2018.18.13) Tesla released late in May. The update is said to address an issue with the Model 3's braking system after some third-party organizations reported exceptionally long stopping distances for the vehicle in testing. We changed nothing else on our car, using the same brakes, the same tires, set at the same tire pressure (45 psi), and the exact same testing protocol we always do. Here's what we found.




XZBIvQ9.webp
 
David Green said:
Lets see the stopping, can it beat 99 feet? I bet not..
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Edmonds 122' was pretty good for the non-perf car on regular tires. Heavy cars.
I'm sure it great comparable to a similar car of weight AND tires. The two major factors.
Many owners already claimed regular braking was great and we are only talking about lower percentage of time emergency braking here anyway!!
 
scottf200 said:
Edmonds 122' was pretty good for the non-perf car on regular tires. Heavy cars.
I'm sure it great comparable to a similar car of weight AND tires. The two major factors.
Many owners already claimed regular braking was great and we are only talking about lower percentage of time emergency braking here anyway!!
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122 is ok, but you rally cannot take the magazine with the best result as gospel... 122 is still nowhere near best in class, Cadillac ATS is 111' in the standard, not V model.
 
An AWD electric car shouldn’t need the largest brakes possible as other than in a couple conditions the regen should be strong enough to haul it down from speed quite quickly. And during those conditions it should need only emergency braking (once) to stop it...
 
Billis deWillis said:
An AWD electric car shouldn’t need the largest brakes possible as other than in a couple conditions the regen should be strong enough to haul it down from speed quite quickly. And during those conditions it should need only emergency braking (once) to stop it...
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Regen is not used at all in panic stop situations, as it would just complicate the anti lock brake system.
 
David Green said:
Regen is not used at all in panic stop situations, as it would just complicate the anti lock brake system.
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Yes...but large robust brake systems that performance cars utilize are sized for consistent repeated braking vs emergency braking which does not necessitate the same specifications. Electric motor braking can and is easily utilized for most braking situations albeit the electric track car will need a robust cooling system for the electrical system as heat is generated there...
 
Billis deWillis said:
Yes...but large robust brake systems that performance cars utilize are sized for consistent repeated braking vs emergency braking which does not necessitate the same specifications. Electric motor braking can and is easily utilized for most braking situations albeit the electric track car will need a robust cooling system for the electrical system as heat is generated there...
Click to expand...


What is your point? Model 3 either has best in class braking or Elon lied... ?
 
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