Braking distance concern by Consumer Reports

[22522]

To increase range, Tesla recommends unusually high tire pressure for the Model 3 (45 psi), could these high pressures contribute to the increased braking distances found by CR?

I dont know, but square tires might? Flat spots.

 

[vinnie97]

And Tesla desperately doesn’t want us to cancel our reservation, since they need all the cash they can have.

So I should also not trust Elon, if he says he’ll fix it?

I hate that “they just do it for clicks” idea. It implies that if someone gets money for the job she/he does, it can’t be objective anymore.

And if nobody is objective, then nobody can prove me wrong. That strategy was used by the Nazis, the Sowjets, the people surrounding the orange guy and pretty much anyone into propaganda.

I should have just bit my tongue, but...certain media outlets *are* shoveling just as much propaganda in one direction in order to increase viewership. Fortunately (or unfortunately depending on your perspective), it has had the opposite effect.

To bring it back to the topic, I don't view CR as that kind of an outlet.

 

[Brando]

It seems like ABS was preventing the tires from locking up at all. The fastest way to stop is with locked tires, now if you wanted to maneuver around an object in your path while stopping, that is where ABS helps.

So, so wrong.
Skidding is NOT as good as maximum friction for stopping which ABS yields.
Do your own internet search and learn the details.

Do locked up tires brake shorter than ABS?

 

[Uncle Paul]

The orange guy is gone. That was candidate Trump. President Trump has a much improved hairstyle and a much more attractive color.

Trump, like many men, suffers from allopecial. From time to time a bald spot will appear. This ia an autoimmune issue, and not really somthing that should be polked fun at. Something a bully would do.

 

[PhantomX]

There are many "testing" tracks around the world. Here is one example. Internet search will provide others.
ZF, TRW Make Powerhouse Technology Team

Hmm, maybe I am missing something, but I don't see Tesla mentioned in there. And I don't recall seeing spy shots of any Tesla testing on tracks.

 

[Matias]

Serious. You just can't compare tesla or really any electric cars to gas cars.

Gas cars just plain suck now that electric is an option..

If we're talking about braking distance, it has absolutely no meaning to talk about gas vs. electric cars. Braking distance is braking distance.

 

[diamond.g]

So, so wrong.
Skidding is NOT as good as maximum friction for stopping which ABS yields.
Do your own internet search and learn the details.

Do locked up tires brake shorter than ABS?

Yeah I was mistaken. Still odd that it would be a calibration issue if CR didn’t report that the brakes locked up. Maybe the ABS system is preventing full brake pressure?

 

[diamond.g]

If we're talking about braking distance, it has absolutely no meaning to talk about gas vs. electric cars. Braking distance is braking distance.

Which varies based on tires even on the same car.

 

[mongo]

That was a non typical use case! 99%

Not sure if this can be said as a non-typical use case though. The overnight pause between 1st and 2nd tests are no different if one had an emergency braking event one night and then have another one next. It's rare, but I would say it shouldn't be classified as non-typical.

You don't think it's a typical use case that someone will ever panic stop with the car from 60mph more than once over the life of the car?

Because that's pretty much what they couldn't get to work.

Yeah, I may deserve some flack for that item one, but here is my thought process:

I'm not referring to two panic stops over the life of the car (or back to back days). Though that shows the induced change is persistent.

The non-typical use case I was referring to is 60-0, one mile drive with 0-60-0, one mile drive with 0-60-0 ... repeat within one drive cycle.

Total speculation on my part: if the tests were spaced out, or performed on different ignition cycles, the system would have behaved differently. It may have triggered the ABS internal calibration routine (if so, it should have a factory mode command/ or done flag added to the code). Sort of like the oil monitor reset sequence (key on, full accelerator press 3 times in 5 seconds, engine start).

 

[mongo]

“the brakes aren’t broken, but we’re fixing them anyway”

Cow droppings, neither Elon nor Tesla ever said that.

Although this person did:

Elon Musk: “There is nothing wrong with our braking, but we will fix it”.

Fine by me. The man must be allowed to save face any way he knows how.

Regarding the early model, that was about the ride and wind noise:

 

[bro1999]

In a recent informal conversation with representatives of a major automaker, the growing role of onboard technology and the use of over-the-air updates came up. One rep suggested that there would always be a hard divide between systems that aren’t essential to the vehicle’s basic operation (navigation and entertainment systems, for example) and those that are (steering, braking, powertrain control systems, etc.). The former can and will continue to be updated remotely, but the latter are perhaps better left disconnected from the wireless world.

That is exactly GM's approach to OTA updates (maybe the "major automaker" was GM). System critical updates will still need to be done by a licensed dealer, but stuff like bug fixes/UI tweaks will be pushed out OTA, like recently with the Bolt.

 

[voip-ninja]

Yeah, I may deserve some flack for that item one, but here is my thought process:

I'm not referring to two panic stops over the life of the car (or back to back days). Though that shows the induced change is persistent.

The non-typical use case I was referring to is 60-0, one mile drive with 0-60-0, one mile drive with 0-60-0 ... repeat within one drive cycle.

Total speculation on my part: if the tests were spaced out, or performed on different ignition cycles, the system would have behaved differently. It may have triggered the ABS internal calibration routine (if so, it should have a factory mode command/ or done flag added to the code). Sort of like the oil monitor reset sequence (key on, full accelerator press 3 times in 5 seconds, engine start).

They let the car sit overnight and when they tested it again the next day it still failed. This was done with multiple cars.

 

[mongo]

They let the car sit overnight and when they tested it again the next day it still failed. This was done with multiple cars.

Right, which means the disturbance which occurred during same-day test was persistent and that the SW reacts consistently the same way to the test profile.

 

[bro1999]

Right, which means the disturbance which occurred during same-day test was persistent and that the SW reacts consistently the same way to the test profile.

What could cause those results, if not faulty braking software? Could it be the OEM brake pads can only stop at Tesla's quoted stopping distances a couple of times before degrading in braking performance? Similar to race car tires getting the "good stuff" worn off after a couple of hot laps?

 

[Sportstick]

I realize it's an artifact of the forum software, but all the quotes attributed to me are actually from the Autoweek article. I was just sharing content I had received in my daily newsletter from Autoweek of interest to this forum.

 

[Trevor B]

The orange guy is gone. That was candidate Trump. President Trump has a much improved hairstyle and a much more attractive color.

Trump, like many men, suffers from allopecial. From time to time a bald spot will appear. This ia an autoimmune issue, and not really somthing that should be polked fun at. Something a bully would do.

You cannot be serious, man!

 

[mongo]

What could cause those results, if not faulty braking software? Could it be the OEM brake pads can only stop at Tesla's quoted stopping distances a couple of times before degrading in braking performance? Similar to race car tires getting the "good stuff" worn off after a couple of hot laps?

I'm not saying the software was not wrong, I'm saying the 0-60-0 mile 0-60-0 mile 0-60-0 mile test routine is not a typical use profile and does not directly indicate the braking software is still in development.
Basically, push back against:

Or more accurately:

CR demonstrates the brake development wasn’t completed before vehicles are sold to the public

and

Elon says they will finish development and then flash the vehicles currently owned by test drivers

(mostly due to the 'more accurately' claim)
which was a response to

I actually like the exchange between CR and Elon. In summary:

• CR found a safety problem that, for whatever reason, didn't get caught yet. They fairly called out Tesla for a potential safety issue.
• Elon responded very quickly and took responsibility to look at it and fix it if necessary up to and including replacing hardware at no cost to the customers.
• After looking into it, Elon admitted the issue, promised a fix and requested a re-test from CR.
• CR committed to re-test after they received the fix.

 

[adaptabl]

If they retest with CR and fail again that will be bad news for Tesla. Also this is a press car. What auto maker would not put it's best car for the press, unless they just wanted to have an excuse if it did poorly.

 

[jtpassat]

The car CR used was not a press car. They purposely buy their own cars to avoid this situation.

If they retest with CR and fail again that will be bad news for Tesla. Also this is a press car. What auto maker would not put it's best car for the press, unless they just wanted to have an excuse if it did poorly.

 

[mongo]

If they retest with CR and fail again that will be bad news for Tesla. Also this is a press car. What auto maker would not put it's best car for the press, unless they just wanted to have an excuse if it did poorly.

Tesla will be testing against the CR methodology before releasing the update. No worries.