[Spoiler Alert + Mild Speculation] Tesla has created a monster!

[scaesare]

My (likely) theory is the lack of drive shafts and wiring to the front wheels means the document is not accurate.

Occam would agree.

 

[e-FTW]

Am only at page 5, but loving the geek out.
Thinking of going back to school to study electrical engineering...

 

[hill]

....snip.......
As for the "weird" aspect... I actually like... no, love... anything that's traditionally considered "weird" but reduces drag. I love sleek, low-drag forms. Shape it like an airplane and you have my heart. The Prius Prime, however, has its weirdness (sorry SageBrush... ) in its styling, factors with no bearing on drag. But, of course, people can disagree about looks!
There's no drag advantage to that "moustache" tail or those "gills" / "mandibles" on the front. No weight advantage. They just... wanted it to look like that for some reason. And some of the details are just strange .....snip.......

no reason to apologize if one thinks a car looks idiotic. Our Nissan Leaf is the Paragon of looking idiotic, imo. But at least it ostensibly served a purpose. Low drag CD. However this new Prius Plug-In, with less than it's sister hybrid's 5 seats, has a crappier drag CD. The company chose to deliberately ignore drag over this kind ofJapanese Power Ranger animation thingy going on. Hey, perhaps younger buyers don't mind.

I would vote that there is more power available than 192kW/ / 258 HP

Could it be it default runs in an efficiency mode with that power (and doesn't do 0-60 in 5.1) unless you get it into some kind of Sport mode?
I don't think there is any switch we saw for sport/insane type alternate modes, but maybe there is some not yet published way to bump up the HP when you want quicker 0-60?
Has anyone heard anything about special launch modes?

considering how much lawsuit saber-rattling there was when it was discovered everyone's top performances we're being throttled back after so many uses .... it would make sense that from here on out - such performance limiting will be well-documented & require signatures before anything with performance happens again.
.

 

[JRP3]

Our Nissan Leaf is the Paragon of looking idiotic, imo. But at least it ostensibly served a purpose. Low drag CD.

Except the horrible styling didn't really translate into an appropriately low cd to justify it, 0.32 as measured by Car and Driver
Nissan Leaf - Wikipedia

 

[McKricas]

So when I plugged in all the values necessary for the Model S (different tires, mass, frontal area, cd, motor curve, final drive, etc), I got what I would consider pretty damn close:

• 0-60 = 4.45 sec
• 1/4 mile = 13.1 sec @ 107 MPH

Not shabby IMO. Great, so let's try the M3! This is where it got interesting......
When I used all the M3 data (tire size, mass, etc.) it came up short from 0-60. It was predicting 0-60 in 5.84 seconds. We know the LR (which is what all the parameters are based off) should be at 5.1 seconds, so what are my levers? Even driving the transmission efficiency to 100% (impossible), only gets me to 5.5 seconds. Lower resistance tires can't get me there. I can't change mass, tire size, final drive ratio, frontal area, or Cd because we actually know these things. I'm open for suggestions of what to try, but my only option was to go to the torque/power curve. Again, the curve is completely flat for basically ALL of the 0-60, so you can't really say it's how I modeled it. I found that if I applied a 1.14x multiplier to the output curve I came in at 5.1 seconds. That would mean that instead of 192 kW motor, it's more like 219 kW (346 HP)! By the way with that 1.14x multiplier I now get:

• 0-60 = 5.1 sec
• 1/4 mile = 13.9 sec @ 101 MPH

Summary:

• I know my first order estimates do NOT consider traction, I'm ok with that for now.
• Something is off with the data, they still aren't coming clean with this car. Either more powerful motor than advertised, lower mass, or ???
• This message is to further the thread...."Tesla has created a monster!" and I don't think they are ready to fess up yet!
• If your interested in the calcs, here's the google sheets:
• Tesla quarter mile calcs.xlsx

I think the problem is the wrong value for mass you're using: 1928 Kg instead of 1740 Kg. Check the EPA document for Model 3 curb weight : 3837 lbs.

Reseting your multiplier and using the correct mass results in a 5.26 sec to 60MPH. If you also take in account that all Tesla measures uses an one-foot rollout during the 0-60 (which improves values a bit) this 5.26 seems about right.

 

[Model 3]

If you also take in account that all Tesla measures uses an one-foot rollout during the 0-60 (which improves values a bit) this 5.26 seems about right.

I thought they only did that for the Performance models?

 

[McKricas]

I thought they only did that for the Performance models?

Until the last Model S/X performance refresh, yes. Tesla measured Perfomance models with the one foot rollout and the rest without.

But after this refresh Tesla started to use only one type of measure, the one followed by Motor Trend's which remove the first foot rollout. This is also one reason for the (much) increase in performance of the latest base Model S.

If you check the Design page it now says the same comment for all models:

"Performance acceleration ratings are based on maximum battery power mode and follow Motor Trend's test procedure of subtracting the first foot rollout time to represent drag strip performance.

 

[Model 3]

But after this refresh Tesla started to use only one type of measure, the one followed by Motor Trend's which remove the first foot rollout.

Thanks for the update...

"Performance acceleration ratings are based on maximum battery power mode and follow Motor Trend's test procedure of subtracting the first foot rollout time to represent drag strip performance.

On the Norwegian page no models got that comment, but it is written at the bottom of the page under the title "Performance" (yes, title in English not Norwegian, as it is on the model name), which I would interpret as "Performance models only". The rest of the text is translated. So this is just like it has been for awhile.

 

[McKricas]

On the Norwegian page no models got that comment, but it is written at the bottom of the page under the title "Performance" (yes, title in English not Norwegian, as it is on the model name), which I would interpret as "Performance models only". The rest of the text is translated. So this is just like it has been for awhile.

Yes, but previously there was a different statement for Regular models (which did not include the rollout). Now, there is only this statement for all models.

Also, it makes sense for Tesla to have only one measure procedure.

 

[insaneoctane]

I think the problem is the wrong value for mass you're using: 1928 Kg instead of 1740 Kg. Check the EPA document for Model 3 curb weight : 3837 lbs.

Reseting your multiplier and using the correct mass results in a 5.26 sec to 60MPH. If you also take in account that all Tesla measures uses an one-foot rollout during the 0-60 (which improves values a bit) this 5.26 seems about right.

Good catch. Yes, it appears that I somehow used an incorrect mass. I don't know where I got it from. Again, thank you for checking my math!

This adjustment puts the quarter mile time at 14.0 (maybe a hair under) @99 mph (maybe 100 mph)...

 

[JeffK]

I don't know where I got it from.

It's from wikipedia's high end weight listing (someone should fix it).

 

[insaneoctane]

It's from wikipedia's high end weight listing (someone should fix it).

Good catch... Makes me feel less like a idiot...

 

[McKricas]

insaneoctane,

A challenge for you if I may :

Taking in account (for instance) that the Model 3 LR - 75kWh battery pack can output ~403 kW of power (and the inverter also supports it), what torque/power do you think the motor should have to give a less than 4 sec 0-60 mph ?

 

[insaneoctane]

insaneoctane,

A challenge for you if I may :

Taking in account (for instance) that the Model 3 LR - 75kWh battery pack can output ~403 kW of power (and the inverter also supports it), what torque/power do you think the motor should have to give a less than 4 sec 0-60 mph ?

By definition of every Tesla torque/power curve I have seen, this is easily done by 403kw. By the way, at 403kW (540 hp) you are at 775 Nm (571 ft lbs). You only need about 273 kW and 525 Nm (367 Hp and 387 ft lbs) to get under 4 seconds.

 

[insaneoctane]

For the record, this estimate is pretty robust because of the simple torque/power curve of EV motors....
You'll notice the torque (red) is at 100% from 0 km/h to about 60 km/h. It is here where it's easy to model different motors, because when the torque starts to fall down, you have reached maximum POWER (blue). As the torque starts to fall, it does so at a rate that has constant power until around 100 km/h. After 100 km/h the torque starts to fall enough that maximum power is no longer maintained. It's pretty amazing that you have solid modeling data from 0 km/h to 100 km/h just by knowing ONE number- the kW rating of the motor. You do have to be able to assume similar gearing. Beyond 100 km/h you have to do some guessing/scaling.

 

[McKricas]

By definition of every Tesla torque/power curve I have seen, this is easily done by 403kw. By the way, at 403kW (540 hp) you are at 775 Nm (571 ft lbs). You only need about 273 kW and 525 Nm (367 Hp and 387 ft lbs) to get under 4 seconds.

Thank you.

So a 273kW combined dual motor power should be the bare minimum for the Performance version of Model 3.

From my calculations the 75kWh battery pack is able to output 1150 A at only 5C of discharge (better than the Model S) for the mentioned 402.96 kW of power.

If the inverter has an ~95% efficiency, the total power to be delivered to the motor will be ~383 kW, which, given the mass of the Model 3, would translate in a very nice acceleration. Probably around 3.0 sec 0-60.

 

[McKricas]

Should also add that I don't see Tesla offering a 3.0 sec Performance Model 3.

It would be too similar to the current P100D for less than half the cost.

I think a value of ~3.8 sec would be good enough without entering too much into Model S territory (2.5 - 4.1 sec).

 

[Nuclear Fusion]

Should also add that I don't see Tesla offering a 3.0 sec Performance Model 3.

It would be too similar to the current P100D for less than half the cost.

I think a value of ~3.8 sec would be good enough without entering too much into Model S territory (2.5 - 4.1 sec).

There's no doubt they will software limit it

 

[Swampgator]

BMW M3 does 3.9.
They will want to beat that. I have long thought they will target 3.1-3.2 secs. That is still almost a full second slower than P100D

 

[tomas]

There's no doubt they will software limit it

Hmm. So you are saying that they will overspec the DU, inverter, battery, etc. for their highest performance 3, and then software limit it to perform below capability even with absolutely no intent to use the extra capacity? That would only possibly make financial sense if they were using the same components in another high volume vehicle (so not new roadster) that would use the full capacity. I don't buy your logic.