Model 3 AWD / Performance - lower UDDS Range!

[autospy]

California ARB just posted their certification for the Model 3 AWD and Performance Models. The listed UDDS is 455.32 miles versus 495.1 miles for the RWD.

https://www.arb.ca.gov/msprog/onroad/cert/pcldtmdv/2018/tesla_pc_a3740023_0_z_e.pdf

https://www.arb.ca.gov/msprog/onroad/cert/pcldtmdv/2018/tesla_pc_a3740022_0_z_e.pdf

 

[WarpedOne]

As expected.
UDDS = Urban Dynamometer Driving Schedule consisting of lots of acceleration.

Hint: your first link links to the same document as the second link

 

[ℬête Noire]

How did the Model S RWD vs D shape up on this test?

 

[MP3Mike]

Your first link points to the same place as the second. The correct link should be: https://www.arb.ca.gov/msprog/onroad/cert/pcldtmdv/2018/tesla_pc_a3740023_0_z_e.pdf

So an 8% hit.

The good news, is this means that AWD/P deliveries are probably going to start soon. (Now where are the EPA documents?)

 

[WarpedOne]

Older Model S UDDS tests are hard to find, but here are some :

 

[autospy]

fixed the link.

The image below shows the UDDS test. We're missing the highway test (HWFET) result. The UDDS and HWFET get combined for the rated range. It is possible that the Model 3 AWD/Performance models are more efficient on the highway test -- we'll have to wait for the EPA docs to be published.

 

[autospy]

Older Model S UDDS tests are hard to find, but here are some :

Nice, so the 2018 Model S 75 scored 333.4 miles on the UDDS and the 2018 Model S 75D scored 345.6 miles.

The Model S saw an increase in range on the UDDS with Dual motors, but the Model 3 is showing a decrease...

 

[ℬête Noire]

Older Model S UDDS tests are hard to find, but here are some :

I also found this in a rando's Comment they seem to have found "UDDS" numbers that are slightly different but without citation so I can't check where exactly they are getting those from?

"Model S 75: 85.5 kWh, 342 miles
Model S 75D: 84.6 kWh, 358 miles"

EDIT: No wait, I read their post incorrectly. The above are the 84 – Charge Depleting Highway numbers. Not UDDS.

Note they also have somewhat different battery sizes listed so it implies that for the same battery the D would see an even larger improvement in miles. I'll try crunch some numbers now to see what kind of drop this will look like, although this might be a lot about the induction versus SR PM motor so outside of accelerating to kick in the front motor there might not be much difference at steady cruise?

 

[Daniel in SD]

I guess this makes sense for a test that's nearly entirely drivetrain loss and tire friction (not fast enough for aerodynamics to be in play). I wonder which tires they were using for the test? I'm guessing none of the decelerations were fast enough to use the presumably improved regen.

 

[ℬête Noire]

Nice, so the 2018 Model S 75 scored 333.4 miles on the UDDS and the 2018 Model S 75D scored 345.6 miles.

The Model S saw an increase in range on the UDDS with Dual motors, but the Model 3 is showing a decrease...

One thing about the 75D is that, I believe, it has a smaller rear motor than the 75. Contrasted with the P variants (although I don't think there was every a P75D, only 85 and larger?). So that might help it out and what's going on here.

 

[FlyNavy01]

As far as I understand it, Model S torque sleeps rear induction motor during cruising speeds to take advantage of the higher gearing ratio up front for better range.

Model 3 PM motor is already more efficient than the induction motor, so the Model 3 likely torque sleeps the front motor when cruising and it just becomes a LR Model 3 with ~150-200lbs more deadweight up front during that phase of driving. This means slightly less efficiency overall due to the added mass, with the tradeoff of added power available from the front motor when commanded by the driver.

 

[Trips]

Are these actual numbers or did Tesla have the option to have them lowered? Could they also be limiting the battery/motors to give them room for improvements and greater reliability down the road?

 

[WarpedOne]

UDDS is an actual dyno run with an 'aero fudge factor' applied.

 

[ℬête Noire]

Are these actual numbers or did Tesla have the option to have them lowered? Could they also be limiting the battery/motors to give them room for improvements and greater reliability down the road?

I don't believe there would be any reason for Tesla to have these lowered anyway, as they aren't customer facing numbers and Tesla wants them higher because it guarantees they received the full maximum of 4 ZEV credits/vehicle sold (which they can then resell to other manufactures that aren't manufacturing as many ZEV accredited vehicles).

 

[TesWhisperer]

So now that the certification is posted, this has to mean that deliveries and very soon, right?

 

[WarpedOne]

As far as I understand it, Model S torque sleeps rear induction motor during cruising speeds to take advantage of the higher gearing ratio up front for better range.

May we also stop repeating this marketspeak of 'torque sleep'? It is just a boring freewheeling of a deadweight, nothing fancy.
It is still better to not have that rotating dead weight at all, fighting acceleration and deceleration, causing drag in bearings.

 

[ℬête Noire]

I guess this makes sense for a test that's nearly entirely drivetrain loss and tire friction (not fast enough for aerodynamics to be in play). I wonder which tires they were using for the test? I'm guessing none of the decelerations were fast enough to use the presumably improved regen.

That's why the Bolt did almost as well on this test as the Model 3 LR but on the highway portion the Model 3 LR blew the Bolt away by nearly 10%. The Bolt has a small frontal cross-section but it's Cd co-efficent on that cross-section is a very brick-like .31.

 

[chillaban]

May we also stop repeating this marketspeak of 'torque sleep'? It is just a boring freewheeling of a deadweight, nothing fancy.
It is still better to not have that rotating dead weight at all, fighting acceleration and deceleration, causing drag in bearings.

Torque sleep still involves trying to control the current loop to 0. You can’t just spin a motor as deadweight without generating a back EMF. That’s especially true for permanent magnet motors, where they will passively generate if spun (it’s actually a serious electrical shock hazard to spin the shaft while the leads aren’t hooked up). In AC induction motors it also turns out to be true because the ferrous metals tend to be weakl magnetized over time. And that’s enough to generate just a little bit when spun.

Back when I was a motor controller engineer we actually used the latter effect to do sensorless startup on induction motors. It was a huge shock (no pun intended) that it worked — but we actually shipped it as a reference platform.

 

[WarpedOne]

In AC induction motors it also turns out to be true because the ferrous metals tend to be weakl magnetized over time. And that’s enough to generate just a little bit when spun.

I was not aware of this fact and stand corrected. Thank you.

Do you have any insight into how 'big' this magnetization effect is and how it effects normal motor operation through its life, say after 150k miles, 10 years of operation?

 

[MP3Mike]

So now that the certification is posted, this has to mean that deliveries and very soon, right?

We still need the EPA certification...