On the S , when it was available as either rwd or dual motor, the dual motor configuration had better range.
One motor is tuned to be most efficient at consistent highway speeds, one at stop and go inconsistent speeds.

 

On the S , when it was available as either rwd or dual motor, the dual motor configuration had better range.
One motor is tuned to be most efficient at consistent highway speeds, one at stop and go inconsistent speeds.

I wonder how the motor is tuned on the RWD. If it's tuned somewhere in between the two motors of the AWD, I can see the lower range overall. If it's identical to one of the motors on the AWD, I would think RWD would always outperform in range in the scenario where the same motor in AWD is engaged and other is idle, since the RWD would weigh less.

Never thought about AWD providing greater range on any vehicle than its 2WD counterpart. Rather fascinating.

 

How can two motors with the same 75KW battery pack achieve the same range as a single motor with the same battery pack? Wouldn't two motors use more energy than one motor does?

That's not *necessarily* the case.

As MelindaV states, the dual-motor S is actually *more* efficient than the RWD version. In that case, the rear motor is geared for acceleration, while the front motor is geared for highway efficiency. The better highway efficiency of the front motor makes up for the added weight (that also means the Model S is a front-wheel drive car during normal highway cruising ).

In the case of the Model 3, it turns out that the AWD version is less efficient than the RWD version. During EPA range testing, the RWD version ended up with a range of 334 miles, while the AWD version received a range of 308 miles. But in both cases, Tesla asked for a "variance" to advertise them both as having a range of 310 miles, which the EPA granted.

https://electrek.co/2018/07/24/tesla-model3-epa-ratings-advertise/

 

As MelindaV states, the dual-motor S is actually *more* efficient than the RWD version. In that case, the rear motor is geared for acceleration, while the front motor is geared for highway efficiency. The better highway efficiency of the front motor makes up for the added weight (that also means the Model S is a front-wheel drive car during normal highway cruising ).

In the case of the Model 3, it turns out that the AWD version is less efficient than the RWD version. During EPA range testing, the RWD version ended up with a range of 334 miles, while the AWD version received a range of 308 miles. But in both cases, Tesla asked for a "variance" to advertise them both as having a range of 310 miles, which the EPA granted.

What explains the lower range on Model 3 AWD compared to RWD and the higher range on Model S AWD compared to RWD?

If the EPA tests were inadequate for the Model 3 AWD, you would think Tesla would have cried foul.

 

Just wish I knew how it lost the 11% (or more specifically, the non-weight-related ~7-%-ish of it) - wheel selection, drivetrain losses, or broken torque sleep - because it really matters in terms of buying decisions :Þ I'm surprised there's not been a proper attempt by anyone to test this out yet. But I'm sure we'll get one.

 

Just wish I knew how it lost the 11% (or more specifically, the non-weight-related ~7-%-ish of it)

maybe EPA test drivers couldn't help themselves smacking on the go pedal with glee? Too ashamed to note it in the test notes?

;-)

 

My AWD model 3 should be here soon, and I will be doing range tests with it against a friends RWD.

 

Excellent!!!!

Don't forget:

• Same route (loop, flat land, at a time and place with little traffic and few stops / starts / sharp turns)
• Same day, close to the same time (but not so close as to be drafting)
• Same speed
• Same tire pressure
• Same wheels and tires, with tires at least roughly in the same tread condition.

Also, ideally:

• Multiple test speeds (55, 65, 75, 85 mph?)
• Rolldown tests (e.g. on flat land, with a camera pointed at the speedo, and at a preferably high speed, shift into neutral and roll to a stop. Then do the same thing in the opposite direction)

We can figure out where the energy is going with this and what the actual efficiency difference is!

 

Let's see, how can this be true?

• All energy sent to rear wheel and the front is left to free wheel?
• 50% energy to front 50% to the back.

These aren't gas engines. They really don't cost anything if they are just sitting there. They are pretty efficient, so 50% front, 50% rear isn't that bad of an option.
But as others have mentioned, Tesla has optimized the power train, allowing one motor to be more efficient at lower speeds and the other better for the higher speed. By using intelligent controllers, they are able to transition between the two without anyone noticing.

So, in reality, the question is more like "Why would you lose efficiency if you had two motors."

 

Everyone should read this excellent summary and analysis of the EPA data by Troy: https://teslaownersonline.com/threads/tesla-model-s-x-3-range-at-65-70-75-80-mph.5496/

 

One thing that hasn't been mentioned yet in this thread is that the rear motor in both AWD and RWD M3s is not an induction motor, instead it's a variant of a permanent magnet motor, which is unique to the 3. That's got to account for some of the difference between the 3 and the S when it comes to single vs. dual motor.

(Source: https://electrek.co/2018/02/27/tesla-model-3-motor-designer-permanent-magnet-motor/)

 

One thing that hasn't been mentioned yet in this thread is that the rear motor in both AWD and RWD M3s is not an induction motor, instead it's a variant of a permanent magnet motor

Oh, we've been discussing that on this forum for quite some time.

Read over these threads:

• PM or induction?
• How do the AWD different motor types complement each other?
• Model 3 drive unit (motor, inverter etc) is 5.7% more efficient than Model S

 

Downhill with a tailwind.

 

Yes, you can. It lets you use physical braking less because you have more total regen capability. Furthermore, a front motor is in a better position for regen than a rear one because the center of gravity shifts forward when decelerating.

While I agree there are limited situations in which the dual motor could recapture more braking energy I will point out that regen braking in the RWD LR Model 3 is strong enough that I never use the brakes above 4 mph. So, for me, the AWD would not recapture more energy except perhaps on snow/ice where the regen could be transferred to the front where there is a bit more traction available for braking. But this would be a very small difference. On a road race course, yes, the AWD could probably capture a lot more regen energy.

 

A little while back someone posted some data about how the dual motor in the S, and any incremental regen that it might provide was essentially negated by the increase in weight. Does that sound reasonable in this case? Certainly the M3 weighs much less than an S, so getting over the power/weight threshold for regen to be able to produce a tiny incremental amount of energy could be possible.

 

Can anyone with a model 3 with AWD post the efficiency numbers they are seeing?

As someone waiting on a non-p AWD car I’m very interested if this car can make it 300 miles on a charge of highway driving. Or if a 250 mike round trip with no charging access can be done easily.

This point greatly interests me as I live in the land that Tesla forgot (also known as North Dakota).

Sorry if this has been posted before, but I’ve been scouring all forums since AWDs started delivering trying to find some efficiency numbers.

 

Here you go:

 

Thank you! This is exactly what I was looking for.

 

If I'm not mistaken that's pretty close to the RWD. 227wh/mile = about 330 miles to a full charge. That sounds good to me.

 

There are a variety of limits in the regen system that may or may not be reached - current to the battery, power from the front motor, traction on the front wheels, ditto for the rear, interaction with friction braking, behaviors programmed by software for various reasons including traction and stability. We know the first - maximum current to the battery - varies according to state-of-charge and temperature. Tesla engineers know how all this plays out, but it's probably too complicated for mere owners to figure out.

I've read that the most difficult thing to develop for the Prius was the brake pedal, including providing the simulated resistance during regen and the transition to friction. There's an indicator that helps you know when you're braking too hard for regen alone. It's interesting that Tesla avoids that complexity by restricting the brake pedal to friction, and the regen to the right pedal.

 

You point out one of my favorite features of the Teslas: the brake pedal is the mechanical brake, regen is controlled by the accelerator pedal. This is way better than attempting to blend regen and friction braking in the brake pedal -- the sense of control in the car is much stronger and regen is entirely automatic; I think Toyota, with a hybrid car, part legacy, part forward-looking, chose a legacy-style control for acceleration and braking, whereas Tesla did the right thing and invented a new paradigm.