Performance Package on Performance Model

[mongo]

The aspect ratio in the tire spec literally tells you the sidewall height as a ratio. That's what the number means.

How To Read Tire Sizes | Goodyear Auto Service



Whoever you spoke to at Tesla is wrong (which happens reasonably often), the previous posters math is accurate.

[/QUOTE][/QUOTE]

With the caveat that loaded dynamic effective circumference is not the same as the base diameter*pi. That is why OEMS have a test machine to roll the tire under load for speedometer calibration. (likely not a huge factor in this case)
Fun factoid: top fuel dragsters gain additional speed/ final drive ratio due to the tire ballooning out as the speed increases.
0-300 in 4.5 seconds

 

[PessimiStick]

Called Tesla as they just told me .5 hours ago that there are no software limits on any Performance versions.

This is quite obviously untrue on its face. Both speeds are software limits. There is a 0% chance that the cars are mechanically incapable of more than 145/155 mph (especially since there is no difference whatsoever between the two packages when it comes to speed).

I can't decide if you're arguing because you just want to be obstinate, or if you actually know so little about cars that you think Tesla's answer is true.

 

[Garlan Garner]

This is quite obviously untrue on its face. Both speeds are software limits. There is a 0% chance that the cars are mechanically incapable of more than 145/155 mph (especially since there is no difference whatsoever between the two packages when it comes to speed).

I can't decide if you're arguing because you just want to be obstinate, or if you actually know so little about cars that you think Tesla's answer is true.

Arguing? Mr. Pessimistic. I'm not arguing anything. How is reporting what Tesla says arguing?

Tesla says....XYZ not me.

If you don't believe them then....fine with me. Call them for yourself.

If you don't believe what they post on their website.....fine with me. Call them and tell them about it.

I haven't voiced my position on either speed. Go back and read.

 

[PessimiStick]

Arguing? Mr. Pessimistic. I'm not arguing anything.

Tesla says....XYZ not me.

If you don't believe them then....fine with me. Call them for yourself.

If you don't believe what they post on their website.....fine with me. Call them and tell them about it.

I haven't voiced my position on either speed. Go back and read.

I don't need to call them. I know the answer. Talking to a random call center employee isn't going to change reality.

Since you seem to admit you have no idea what you're talking about, you should probably stop.

 

[Garlan Garner]

I don't need to call them. I know the answer. Talking to a random call center employee isn't going to change reality.

Since you seem to admit you have no idea what you're talking about, you should probably stop.

Nope....aint going to happen. Since you seem to know more than Tesla maybe you should ignore the conversation.

Tesla @ 888-518-3752 / the Westmont Il store and others here say its Tire size.

 

[thewishmaster]

Not to derail the speed discussion but has anyone seen good feedback with respect to ride quality on 20s, especially since the 20” sport wheels are now available for the Model 3? I’m pretty much set on ordering the P3D with the performance upgrade but I can’t tell what to expect with respect to ride quality.

 

[PessimiStick]

Tesla @ 888-518-3752 / the Westmont Il store and others here say its Tire size.

They could say it was because it was powered by unicorn farts and cyclops tears. Those are equally plausible, and none change reality. Let it go dude, sales people are uninformed, news at 11.

 

[Garlan Garner]

They could say it was because it was powered by unicorn farts and cyclops tears. Those are equally plausible, and none change reality. Let it go dude, sales people are uninformed, news at 11.

This is for the benefit of the readers.

I just called Tesla and got the same response as I asked them the same question a different way. I asked.

"What if I get the 18 Aero rims in the configurator and then purchase your 20 OEM rims on your website a month later and install them....will you bump me back up to 155mph top speed?

Answer = why do you believe its software limited?

I should have told them the Pessimistic programed it that way...but I didn't.

I told them that it was stated in a forum that the 10mph is a pre-programed difference. She said....its a change rim/tire diameter. There is a max rotation on the hub. Install a larger diameter set of tires and you will travel faster.
I then asked....Wouldn't that make my speedometer be off? She said it will be negligible 99% of the time.

 

[PessimiStick]

I just called Tesla and got the same response as I asked them the same question a different way. I asked.

"What if I get the 18 Aero rims in the configurator and then purchase your 20 OEM rims on your website....will you bump me back up to 155mph top speed?

Answer = why do you believe its software limited?

I should have told them the Pessimistic programed it that way...but I didn't.

I told them that it was stated in a forum that the 10mph is a pre-programed difference. She said....its a change rim/tire diameter.

And she is wrong.

I would literally bet $100,000 on it, right now.

Edit: In response to your edit, I don't actually believe that you had that conversation, or I greatly underestimated the stupidity of the salesperson you talked to.

 

[Garlan Garner]

And she is wrong.

I would literally bet $100,000 on it, right now.

You have $100K in the model 3 forum?

You should be in the Model S thread. Just kidding. lol

 

[Knightshade]

If you want to argue? - Aint gonna happen.

I'm not arguing with you I'm correcting your errors of fact, and explaining to you the info you claimed we "don't know" is literally written on the side of the tire.

And thus your "explanation" from whoever you supposedly spoke to makes literally no factual sense because of the math you initially dismissed and then claimed you understood but don't appear to understand how it contradicts you.

Called Tesla as they just told me .5 hours ago that there are no software limits on any Performance versions.

And we've already explained that the given explaination is factually nonsense based on known specs and math.

Therefore either the guy you spoke to:

1) Lied to you.
or
2) Didn't know or understand the actual reason for the speed difference and misrepresented it by accident or ignorance to you.
or
3) Said something you heard or understood incorrectly.


As I explained, given the facts we have right now, your explanation is impossible, and I listed the only 2 possible ones for you.

One of them, the far more likely one, is a software limit.


Now- if further facts nobody has given come to light (say- they somehow get a special tire for the 18" P wheels that's not rated to 155 for some weird reason) then another possible reason would exist. But that's not consistent with currently known facts.

And your "tire size" bit is complete nonsense directly contradicted by basic math.

Tesla / Elon and the crew obviously don't know what they are talking about.

Your suggestion that Elon was the one you spoke to is even less credible than the explanation you're trying to claim you were given

 

[lairdb]

(Ignoring deformation at speed.)

235/45R18: 82.7 inches circumference; 766 revolutions per mile
235/35R20: 83.1 inches circumference; 762 revolutions per mile.
(tiresize.com/comparison/)
(Incidentally:
- the same page indicates that this size difference will result in an indicated speed error of 0.7mph at 90mph,
- the MCU does under certain circumstances ask what wheel size is mounted, and may be accounting for even this difference.)

140 mph = 2.33 m/minute.
2.33 * 766 = 1787.33 revolutions per minute.
1787.33 * 83.1 inches = 148527.4 inches per minute.
148527.4 inches per minute = 2.344182449 m/minute.
2.344182449 m/minute = 140.651 mph.

Either
- deformation at speed is substantially (15x?) greater on the 18 than the 20, or
- I made a maths error, or
- something other than wheel RPM is in play.

(Thank you to mongo for pointing out that I typed "diameter" when I meant to type "circumference".)

 

[FlyNavy01]

(Ignoring deformation at speed.)

235/45R18: 82.7 inches circumference; 766 revolutions per mile
235/35R20: 83.1 inches circumference; 762 revolutions per mile.
(tiresize.com/comparison/)
(Incidentally:
- the same page indicates that this size difference will result in an indicated speed error of 0.7mph at 90mph,
- the MCU does under certain circumstances ask what wheel size is mounted, and may be accounting for even this difference.)

140 mph = 2.33 m/minute.
2.33 * 766 = 1787.33 revolutions per minute.
1787.33 * 83.1 inches = 148527.4 inches per minute.
148527.4 inches per minute = 2.344182449 m/minute.
2.344182449 m/minute = 140.651 mph.

Either
- deformation at speed is substantially (15x?) greater on the 18 than the 20, or
- I made a maths error, or
- something other than wheel RPM is in play.

(Thank you to mongo for pointing out that I typed "diameter" when I meant to type "circumference".)

I agree. 140mph equates to ~16,000rpm at the motor because of the 9:1 reduction gear ratio. That just means the 155mph option software unlocks the motor up to it's full 17,900rpm as I stated earlier in this thread.

I assume the front induction motor will have a slightly different peak rpm and gear ratio, just like all dual-motor S/X's, to achieve better efficiency at highway speeds.

 

[favo]

Per tirerack.com the OEM tires are

Rim  Model                      Size        Diameter  Revs/Mile  Max Load        Max Speed    UTQG      Note
19"  Continental PROCONTACT RX  235/40R19   26.4"     787        96 (1,565 lbs)  W (168 mph)  400 A A   TO Tesla ContiSilent
20"  Michelin PILOT SPORT 4S    235/35ZR20  26.5"     786        92 (1,389 lbs)  Y (186 mph)  500 AA A  TO Tesla Acoustic Tech

So, almost no difference in diameter.

ETA: Contis, Michelins

 

[mongo]

I agree. 140mph equates to ~16,000rpm at the motor because of the 9:1 reduction gear ratio. That just means the 155mph option software unlocks the motor up to it's full 17,900rpm as I stated earlier in this thread.

I assume the front induction motor will have a slightly different peak rpm and gear ratio, just like all dual-motor S/X's, to achieve better efficiency at highway speeds.

The PMSR rear motor is more efficient than the AC Induction front (no rotor losses). I predict the front motor will torque sleep 99% of the time...

 

[FlyNavy01]

The PMSR rear motor is more efficient than the AC Induction front (no rotor losses). I predict the front motor will torque sleep 99% of the time...

Now that I think about it, you're probably right.

 

[favo]

The PMSR rear motor is more efficient than the AC Induction front (no rotor losses). I predict the front motor will torque sleep 99% of the time...

You're driving it wrong.

 

[Petra]

At this point, since both tires are rated for speeds over 155, there's only 2 possible explanations-

1) It's just a software unlock (more likely)

2) There's some bizarre instability that only happens above 145 mph that is fixed by the spoiler included in the "performance" pack (this is exceedingly unlikely- but is the only, relevant, mechanical difference we know of between the 18"P and the 20"P)

There is a 3rd, and somewhat silly sounding, option: either due to rotational speed (though, only ~128rpm difference between 145 & 155mph), aerodynamic forces, wheel flex, rebound stresses, or some combination thereof, the aero covers fail and/or can't reliably stay on above 145mph.

 

[Knightshade]

There is a 3rd, and somewhat silly sounding, option: either due to rotational speed (though, only ~128rpm difference between 145 & 155mph), aerodynamic forces, wheel flex, rebound stresses, or some combination thereof, the aero covers fail and/or can't reliably stay on above 145mph.

If that were the case they wouldn't be able to sell the 18" aero winter package folks have mentioned to people who bought sport pack cars... but I appreciate the idea

 

[Petra]

If that were the case they wouldn't be able to sell the 18" aero winter package folks have mentioned to people who bought sport pack cars... but I appreciate the idea

Yeah, that crossed my mind... just trying to come up with alternatives. I'm not actually arguing that it isn't a software lock to entice people to drop more cash.

On the other hand, who knows if the 18" winter wheel package information was correct... I mean, the range and staggering stupidity of answers people get from front line Tesla staff knows no bounds and the words "I don't know" seem to be missing from their customer service vocabulary.

What kills me is that the core of this whole conversation, whether upgraded brakes are exclusive to the Performance Upgrade package or if there's some extra upgrade over stock performance or whatever, can only be answered by Tesla (up until people start taking delivery, of course)... yet, their front line staff are so poorly trained/informed that they don't really have answers.