Braking distance concern by Consumer Reports

[Daniel in SD]

what are you seeing that indicates the braking issue was only with the early production cars?

Reread the tweets and I guess I misinterpreted them. Musk points out that CR has an early production car but doesn’t say the brakes are related to that.

 

[Daniel in SD]

Agreed. 100%.

Anybody know how to precisely measure stopping distance? It'd be interesting to do our own test (several back-to-back actually) and then repeat the test after the firmware update comes out. Even if your accuracy isn't that great, then reasonably high precision would show the improvement (look up the difference if you don't already know).

I think VBOX is the gold standard but it costs $10k+. There are cheaper options Tesla Electronics G-tech/Pro RR, $300
They claim it works really well for 60-0 measurement

 

[jamnmon66]

Maybe I'm beating a dead horse but I can't get over how impressed I am at how Elon is handling this. Compare this to how other automakers work. It's stunning. If a firmware update indeed fixes it then very few people will even realize there was a problem.

Counterargument I suppose is that more R&D would have prevented it.

 

[jamnmon66]

I think VBOX is the gold standard but it costs $10k+. There are cheaper options Tesla Electronics G-tech/Pro RR, $300
They claim it works really well for 60-0 measurement

Hmm... anybody have access to either of those? I'm curious but I'm not sure that I'm $300 curious.

 

[PhantomX]

Ok, that was my mistake then. I didn't know where the Porsche track was, but knew Edmunds is in LA. When you said Carson, I was thinking it was tested in Nevada, but that's Carson City, so I was figuring the A4 and BMW were tested in LA and the Model 3 in NV for some reason. I would say the pavement being the same piece is the most important for getting consistency across different cars.

Yes, the inconsistency is the main problem with CR's findings. Hopefully Elon is right and that it's an ABS calibration algorithm issue that can be fixed OTA.

No worries, I did forget there are other Carson out there;-)

Believe it or not, I would actually feel better if this problem is purely hardware than a software problem. Fixing braking distance issue is fairly straightforward if budget is available and the problem exist strictly with the hardware. A software issue is a different animal, and they'll need to make sure fixing this doesn't cause other brake issues to pop up.

 

[Gear]

Maybe I'm beating a dead horse but I can't get over how impressed I am at how Elon is handling this. Compare this to how other automakers work. It's stunning. If a firmware update indeed fixes it then very few people will even realize there was a problem.

Counterargument I suppose is that more R&D would have prevented it.

Yeah, I just wish he handled everything like this rather than the way he's handled some other criticism lately.

 

[thegruf]

Elon's response is absolutely and refreshingly the correct one, and absolutely you would not see this response from other auto manufacturers. You should see the manufacturers squirming out of safety + eco related recalls in the UK with our gutless authorities when the exact same vehicles have mandatory recalls in the US

That said, given the first stop is good, subsequent ones are worse and are variable, how this is fixed by software?
I get ABS can be recalibrated but if the first stop is good (assuming ABS kick in) for subsequnt stops to be worse shows a noticeable mechanical deviation.

Most likely this would be due to the pad material degrading following the "heat treatment" of the first stop.
More likely I suspect a supplier quality issue with a batch of pads.

So I expect improvements to the ABS software quickly, followed by a period of Tesla analysing batches of pads internally, possilby followed by a pad replacement program (rangers?) for a limited range of VINs, and if the above is correct a likely renegotiation with brake pad suppliers.

 

[PhantomX]

I am curious, does Tesla do any track test besides the one they have in Fremont? Most of the major manufacturers have their large proving grounds to push their cars hard, and many of them also go to Nurburgring to test their cars. This brake consistency issue should have popped up if the car has been pushed on a track repeatedly.

 

[sreams]

Wow, BMW i3 60-0 distance is 108 feet

BMW i3 has much less range due to having a much smaller battery, and as a result weighs 800 lbs less than a LR Model 3. Of course it will have a shorter braking distance.

 

[SageBrush]

BMW i3 has much less range due to having a much smaller battery, and as a result weighs 800 lbs less than a LR Model 3. Of course it will have a shorter braking distance.

True, but have you seen the tyres on those cars ? The result is impressive.

 

[jschwefel]

I’ve been driving the Model 3 since mid-February and haven’t had or noticed any braking issues. The car is amazing, and because of regenerative braking, I find myself hardly using the pedal brake. I haven’t had to do any emergency stops, but nothing suggests the brakes are inadequate. In fact, looking at the size of the rotors and calipers, I’m quite confident there’s plenty of stopping power.

I have noticed though even after about 3000 miles, the disk rotor surfaces still have a dull appearance to them and may not be fully broken in. Could this impact the braking distance in an emergency stop? Probably. I’m not saying this caused the inconsistent braking results CR experienced, but break-in periods could have something to do with it. Maybe I’ll set the regenative braking to “Low” for a while to allow the mechanical brakes to wear in quicker. Cool, now I have another reason to drive the car some more.

 

[Rob R]

I am confident the braking distance issue can be fixed, and Elon is saying he will fix it, it looks more like unacceptable variability than a design issue, which should be a question of snagging at Quality Control somewhere at Fremont.
We all know the single screen is a design choice, and I am quite prepared to live with that. With improved voice control, it will be less necessary to press the screen while driving, and Tesla have already brought a couple of common functions from the screen to the buttons on the wheel, speed setting and distance setting. Most people will find their ideal settings and leave them alone until parked. And of course autosteer plus adaptive cruise means you can take eyes off the road briefly far more safely than with most cars.
The wind noise at highway speed issue seems to be a design care and attention issue. This is quite easily fixed. I have seen easy install aftermarket options to "fill up" roof channels that attract wind roar that seem to work well. I am less confident Tesla will fix this, because why exactly should you pay for Model S if not this sort of thing?
The rear seats will not support your thighs, because the seat is too low your knees are up in the air. If the seat was higher tall people would not have head room. Short people can buy a cushion. Or buy their own Model 3 if the cushion is too expensive!

 

[whitex]

Comparing stopping distances recorded by any one tester with those from another tester will always show differences. Kind of like running a compression check. Two testers on the same engine will show different results.
What counts is consistency of method. If CR always does it the same way and found an issue, chances are pretty good there's a real live issue someplace. But putting their numbers against Tesla's proves almost nothing, except that the tests were probably different.
Robin

Same tester (CR) measuring 34 feet shorter 60-0 on a Model S:
Tesla P85D Handling, Braking, 0-60 Test Results

 

[whitex]

I am confident the braking distance issue can be fixed, and Elon is saying he will fix it

LOL. Elon said my P85D could produce 691hp, and just like here he said an OTA would fix it (since it was only making 463hp when I got it, but I trusted Tesla that they will deliver - 3 years later, not much trust on ANY promises as the trail of broken ones is not short).

 

[bro1999]

Maybe I'm beating a dead horse but I can't get over how impressed I am at how Elon is handling this. Compare this to how other automakers work. It's stunning. If a firmware update indeed fixes it then very few people will even realize there was a problem.

Counterargument I suppose is that more R&D would have prevented it.

Other automakers would have had the braking systems properly tested BEFORE public release.
How many times did you take in previously owned cars less than a year old to the dealer to fix a software issue with the braking system?

 

[bro1999]

BMW i3 has much less range due to having a much smaller battery, and as a result weighs 800 lbs less than a LR Model 3. Of course it will have a shorter braking distance.

The now ancient Gen 1 Volt had a 60-0 stopping distance of 119 feet according to MotorTrend. It weighs a whopping 50 pounds less than the LR Model 3. You'd think a performance oriented Tesla would have the braking performance to match.
2011 Chevrolet Volt First Test - Motor Trend
Braking, 60-0 mph 119 ft

 

[Xenoilphobe]

CR says their standard cool down is about one mile.


The 3 has aero covers based on the site pic...

I think it might be a possibility that the car might have brake fade, due to heat buildup with the aero covers on. Only way to test it is to pull the covers and redo the test and also monitor each run with a FLIR gun that measures the brake temps.

 

[bro1999]

I think it might be a possibility that the car might have brake fade, due to heat buildup with the aero covers on. Only way to test it is to pull the covers and redo the test and also monitor each run with a FLIR gun that measures the brake temps.

They also let the brakes cool overnight and borrowed another 3 from an owner to test. Results were the same.

 

[Xenoilphobe]

Then put Michelin pilot super sport tires on it and redo the test. Small changes to tires and pads and even brake fluid have significant impact on braking.
They will nail this. Hoping they go over board on the P3D with a sub 100 feet stopping distance and hand everyone a cup of STFU. The media monkeys keep the clicks coming for Tesla.

 

[mongo]

They also let the brakes cool overnight and borrowed another 3 from an owner to test. Results were the same.

Couple thoughts there:
If brakes are glazed, sitting overnight won't help.
When they say results were the same on seconds car, they don't say if the results were one 130ish foot stop followed by longer stops or only all longer stops.

From Elon's recent Tweets, it sounds like the test protocol may be interacting with the ABS software.