New Rear Brake Calipers For non-Performance Model S and X

[Yinn]

Im so conflicted about this. On the one hand, those 4 pot calipers are worth significantly more money. On the other, the simpler design requires less mainteanance and less to go worn down the line.

On my third hand....with regen. What are brakes again?

Thanks for the info!

 

[u00mem9]

No silver lining to this one. This is a definite downgrade for cost reasons.

 

[MP3Mike]

No silver lining to this one. This is a definite downgrade for cost reasons.

It is also possible that the new version will be more reliable. Since you have the caliper being worked significantly every time you park, instead of only when you stomp on the brakes. (And they may have made other reliability changes based on some of the corrosion and freezing that some people have reported of the calipers.)

 

[larmor]

If they cost less, and are simpler in design, they should be cheaper to replace/repair...

 

[u00mem9]

Actually, "parking calipers" such as this have historically been far less reliable than the fixed caliper design with separate parking brake. (which is usually in the form of a small drum brake inside the rotor hat, but because Tesla needed the parking brake to serve as the parking pawl, a separate electric parking caliper was applied). Sliding calipers such as this have a poor record in salt environments and often seize at the sliding interface resulting in performance and uneven wear issues. And the big brembos made sense as Lola pointed out, the rear bias and low cg of the model S allow it to use the rear brakes much more than a comparable traditional vehicle. (Less weight transfer and more initial static rear bias)

These are Honda level parts on a premium vehicle. They will be cheaper to replace but that is like saying I'm glad they changed the suspension control arms from forged aluminum to stamped steel...that will really save me money when I replace them.

I'm guessing these are a surprise to people that ordered expecting the brembos and getting something else. I'd be pissed, but rationalize it if you must, or have no other recourse. With the elimination of the P90D, the price of entry for full brembo equipment is now $130k+! Ouch.

 

[larmor]

Actually, "parking calipers" such as this have historically been far less reliable than the fixed caliper design with separate parking brake. (which is usually in the form of a small drum brake inside the rotor hat, but because Tesla needed the parking brake to serve as the parking pawl, a separate electric parking caliper was applied). Sliding calipers such as this have a poor record in salt environments and often seize at the sliding interface resulting in performance and uneven wear issues. And the big brembos made sense as Lola pointed out, the rear bias and low cg of the model S allow it to use the rear brakes much more than a comparable traditional vehicle. (Less weight transfer and more initial static rear bias)

These are Honda level parts on a premium vehicle. They will be cheaper to replace but that is like saying I'm glad they changed the suspension control arms from forged aluminum to stamped steel...that will really save me money when I replace them.

I'm guessing these are a surprise to people that ordered expecting the brembos and getting something else. I'd be pissed, but rationalize it if you must, or have no other recourse. With the elimination of the P90D, the price of entry for full brembo equipment is now $130k+! Ouch.

Rationalize: get brembo's in lieu of FSDC with multi teraflop supercomputer in your car. Then brakes will actually matter.

 

[NikeWings]

I have no inside information, I am just speaking about the current Tesla line up. They could very well change the Performance rear brakes with these at some point but that is not their current intent from what I have heard

After seeing your original post, I called my 'go to tesla guy' regarding my X P100D on order and this was his response:
"As for the change to the brakes – it is a slight configuration change to the rear brakes of non-performance cars, we are switching from a dual caliper setup to a single caliper, this does not impact safety or performance. For any P100DL order you will have the same setup we have used for our cars with a dual rear caliper setup."

 

[u00mem9]

Rationalize: get brembo's in lieu of FSDC with multi teraflop supercomputer in your car. Then brakes will actually matter.

I agree it won't matter at the autonomous point. But a) we aren't there yet, and some think won't be before these cars are traded up. And b) ap2.0 hardware was announced and people paid for it. No surprises although a few orders timed well may have gotten free upgrades. In this situation it looks like a few are getting free downgrades. Too bad tesla doesn't have model years like those square automakers, or you might know what you are getting when you order (sarcasm)

 

[lolachampcar]

It would be interesting to do a back to back (or side by side) threshold braking test using pre and post rear caliper change. Given Tesla's ability to lean harder on the rears, I would expect an increase in stopping distance under full ABS actuation.

In short, I'm skeptical of Tesla's claims of no reduction in performance but would love to be proven wrong.

 

[NOLA_Mike]

Looks like the cut off date for getting the older style was cars produced before 11/22/16. That's the stipulation now to buy the "red caliper brake set" from the accessories shop.

Tesla — Model S Red Brake Calipers Set

 

[NOLA_Mike]

In short, I'm skeptical of Tesla's claims of no reduction in performance but would love to be proven wrong.

I'd like to think Tesla's claim correct under "normal" braking conditions and you'd only notice an improvement on the older style under heavy use or track conditions.

Hey, with a new 90D on order that's what I'm telling myself for now...

 

[u00mem9]

Looks like the cut off date for getting the older style was cars produced before 11/22/16. That's the stipulation now to buy the "red caliper brake set" from the accessories shop.

Tesla — Model S Red Brake Calipers Set

Good catch! I'm a little disappointed they wouldn't make these an optional upgrade for cars with the new calipers. Re flash the abs ecu/vsa is all that should be required for compatibility

 

[Hubris]

It would be interesting to do a back to back (or side by side) threshold braking test using pre and post rear caliper change. Given Tesla's ability to lean harder on the rears, I would expect an increase in stopping distance under full ABS actuation.

In short, I'm skeptical of Tesla's claims of no reduction in performance but would love to be proven wrong.

after a few panic stops testing on an abandoned road and using road stripes and concrete sidewalk sections to measure stopping distance, comparing these with a friend's 70D using the old design they were within the margin of error of braking distance. Even me, somebody who normally complains about brakes in performance cars I dont feel any difference in stopping or threshold breaking. If I was buying a 911 and this change was made I might care, but on the Tesla I dont think it matters other than visually. Nobody tracks these things. I'll see how it does on tail of the dragon, maybe the new rear unit will deal with heat worse but I dont think it would matter to any actual Tesla buyer. [Just us nit picky folks] I don't even care that it is probably a cheaper unit, I'm all for Tesla saving some money to help further fund their mission. As long as these new rear brakes hold up long term I see no reason to worry about it. Nice to see that they perform about the same in my unscientific testing though.

 

[lolachampcar]

Thanks for putting time into the comparison and the feedback!!!

 

[Whitmarsh]

New Model S and X are now being delivered with a different rear brake setup for non performance cars. (60/75/90kW cars) Performance trim cars retain the previous design.

Highlights

• Single Piston rear brake caliper now replacing 4 piston rear caliper for non performance models
• Integrated parking brake in the unit (no longer needs the smaller secondary caliper)
• Braking performance and safety remains unchanged (rear brakes only account for a small fraction of overall braking force)
• simpler overall design

Today I took a peek at our Model S 75D which was just dropped off at the SC yesterday. It now appears all new Model S and X cars that are not performance trim will be using the new unit. I will try and film a comparison when we take delivery of the car. I am curious to see if these new rear calipers are any quieter when engaging the parking brake than the previous design. (will try to get a better picture as well)

View attachment 204826 View attachment 204827

Thanks for this post and the comparison later on; very interesting, especially as I have a car on order. One thing I can't see explained: how does the parking brake now work? Is it still electrically activated? On - and what make are the new calipers?

 

[Yinn]

Nice to see that they perform about the same in my unscientific testing though.

Thank you for doing this.

I think it would've been nice to find out officially too. Nitpick or not, some might have taken it into consideration for a inventory/cpo/new order situation. The lack of model years doesn't help either.

 

[Inverse]

Tesla takes the silent downgrading way.. no free SC, brakes, what's next? Not happy as future customer

 

[lolachampcar]

at the same time, my wife's new S90D is a WAY better car than the S85 it replaced. They are making the cars much better as they go and, I do not know about you, but I almost never use the brakes. If they had to touch something, I'm just as happy that they do so on something I do not use

 

[u00mem9]

Yes, I agree they make more silent improvements than downgrading.

Still, the consumer deserves to know what they are ordering. Someday someone will be tearing their hair out at the parts counter for the complete lack of tracking Tesla has done for various running changes.

 

[MP3Mike]

Someday someone will be tearing their hair out at the parts counter for the complete lack of tracking Tesla has done for various running changes.

How do you know that they aren't tracking the changes? Just because they aren't sharing them with you doesn't mean that they aren't tracking them. I saw someone that said they went to a service center to get a part and the counter guy said I have to have the VIN because there are like 13 revisions of that part. So I assume with the VIN they know exactly what part number fits.