2015 Frankfurt/IAA Auto Show Prius Second Showing

Thanks for the detailed review. The implications of load efficiencies are coming back to me now.

Is this a fair summary of the situation?

• Car motors operate at part load most of the time
• The type of motor used by Tesla (induction motor) is less efficient at part load than full load
• By using 2 motors rather than one and switching one off at lower loads, Tesla improve efficiency under most operating conditions.
• The two motors could be set up to drive the front wheels together, to drive the front wheels individually, or to drive the front wheels with one motor and the rear wheels with the second motor which is the option Tesla has chosen
• The type of motor used in the Prius thus far is most efficient at low loads so adding an extra motor would not provide this particular efficiency benefit (there are other potential benefits such as 4WD)

 

Thanks
Some photos looking toward the rear from the drivers seat and from the center mirror would help tell us whether lines of sight to the rear and the rear quarters are improved, worse or much the same.

 

Excellent. Try to bring along a "selfie-stick" and use it to take photos or a video of the underside of the car with the camera light enabled all along the car from front to back.

But first, make sure there aren't any other people standing around in skirts or dresses or you might get in trouble....

 

Especially in a Tesla!

Most motors are, but the curve is worse for a squirrel cage induction motor than most.

To be clear, that was an example. I don't know that they actually do this but they could. What I'm sure they do is map the efficiency surface (efficiency versus power and RPM) and pick an optimal point for where they are currently operating.

No, just one motor on the front and one on the back. So no opportunity to control one wheel at a time.

I didn't say it wouldn't, but the effect would be reduced, possibly to zero or less if you include windage and friction losses, and also increased rolling and acceleration losses due to extra weight.

 

There's a pretty good pic of the rear underside, albeit a bit too closely cropped. Don't see anything untowards, tho I wouldn't know what to look for. Post 47 here:

2016 Prius Eco | Page 3 | PriusChat

(click image to get higher resolution)

 

I think Tesla also uses different gear ratios for the front and back motors so that gives another dimension to play with and balance for best efficiency and torque at different vehicle speeds and motor rpms.

The 2WD 2016 Volt gets some of this effect as well since it can use either or both motors in the transaxle together (attached to separate planetary gears sets) at somewhat different motor gear ratios when the gas engine is off. A one-way clutch prevents the gas engine from spinning backwards when the smaller motor is energized so it can add to the total torque output.

A future Toyota PHEV with the 2 planetary gear set HSD could easily add a passive one-way clutch to the engine to play this game too, especially if it had battery output power large enough to come close to or exceed the larger motor (MG 2), even if they chose not to add something like the Volt's other two actively-controlled clutches.

 

You can see the horizontal arms of the (independent) rear suspension. IS there a rear axle?

 

All Prius up to now have a solid rear axle. Maybe you are confusing the axle with the half-shafts.

 

I think that channel on the right is the axle in that picture. It connects the two wheels together. It, of course, doesn't spin or carry drive power.

 

The axle is the shaft that the wheel spins on. An axle may or may not spin itself. In the example shown each rear wheel has a separate axle that is just a few inches long.

 

There is a black & white interior new Prius in 2015 Frankfurt/IAA Auto Show

Bwinternal by Grus posted Sep 16, 2015 at 12:06 PM

Captured some screens from the AutoMotoTube's Youtube video

And for the record, the official TOYOTA Press Conference recorded by Motoren & Mehr
no more details than the Press Release text ...

 

That's a hub or spindle.

 

Axle
Axle - Wikipedia, the free encyclopedia

 

I see "backup sensors" on both the rear and front of the car! Great addition!

 

I have counted 12 sonar sensors from PriusChat's Las Vegas photos, although obviously they are for the upper models.
CRAZY? Even current Lexus LS600hL "just" have 10 sonar sensors.
Here is a mixed picture:

ICSx12 by Grus posted Sep 16, 2015 at 12:35 PM