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An Anonymous Coward writes:
Until now, electric cars could be broken down nicely -- at the high end there is Tesla S & X, and then there is everything else (possibly including Tesla 3). A few possible competitors either quit early (Fisker) or haven't made it to production yet (Lucid, Faraday Future). This split covered price, luxury and range. Now there is a serious competitor from Jaguar and Motor Trend tested the I-Pace in Europe. While they report trouble finding charging points (it's a new car after all), they generally seemed to be impressed.
As BEV platforms go, the I-Pace’s skateboard layout is conventional. There’s a motor at each end, one driving the front wheels, the other the rear, and in between is a liquid-cooled 90-kW-hr battery pack with 432 lithium-ion cells that also provides structural integrity for the chassis. The Jaguar-developed motors are synchronous permanent magnet units with concentric transmissions that align the motors with the axles. Total output is 394 hp and 512 lb-ft.
[...] Much of Germany’s autobahn is subject to speed limits, so we spend a lot of time at 75–80 mph. There’s not much wind today, but the higher speed boosts consumption to 43 kW-hr per 100 miles. On one derestricted stretch I wind the I-Pace up near its 124-mph Vmax. It gets there easily, but I burn 6 miles of range in the process (and yes, a gasoline version would also burn fuel with such a surge). Feeling guilty at the extravagance, I back off and settle down to 75–80 mph again.
(Score: 1, Interesting) by Anonymous Coward on Saturday June 09 2018, @04:05PM (1 child)
> It seems to me that if you put the engine at the other end of a short shaft, just a shaft with no gears or other complications,
As a minimum it's going to need a constant velocity (CV) joint at the wheel for steering and reasonable suspension geometry. For a non-steered (rear) wheel there is swing axle suspension (Beetle, Corvair, etc) that has no outer joints, but expectations for handling have gone beyond swing axles...
> IIRC Subaru AWD has been computer controlled for a long time
Audi, Subaru and many others have used electric/electronically controlled diffs for quite awhile. I believe that these generally (don't know about every kind) default to a reasonable passive system *when* the electronics fails.
(Score: 3, Interesting) by Arik on Saturday June 09 2018, @05:45PM
Well yes, correct, I should have been less categorical, let's say *minimum* of gears and other complications, obviously there has to be a linkage to let the shaft change attitude without tilting the wheel and vice versa, but that's something every (modern) car has regardless if I'm not badly mistaken here. I looked up swing-axle and this is nothing like what I am thinking of. It would basically be a wishbone suspension, well I guess it really would be a wishbone suspension, because what would change is only the bit that's carrying the power, not the suspension itself.
Reading back on that, I'm sure my wording is confusing and that's not entirely unrelated to the writer being a bit confused as well. But the basic point I'm trying to make is that four engines per wheel does not require actually mounting in the hubcap to eliminate a lot of heavy gear, just mounting them closer to the wheel would still eliminate a lot of heavy and expensive gear. You can even tune the weight-distribution by moving them in or out slightly, even if the way I described it initially was confused. And since it's going to be computer controlled either way, whether with a central powerplant and drivetrain or separate powerplants, that doesn't seem like a good objection.
"Audi, Subaru and many others have used electric/electronically controlled diffs for quite awhile. I believe that these generally (don't know about every kind) default to a reasonable passive system *when* the electronics fails."
I mentioned Subaru because it's the one I have a lot of experience with. It's always worked very well for me and I'm not aware of any major problems with it. I was skeptical when they went to that - I LIKED my fully manual Subaru I learned to drive on that car and I knew I could trust it. But the new transmissions have earned respect, they have always worked quite well for me.
Of course when I say 'new' transmission that's all relative, I haven't drive a truly recent one. For all I know they have finally rewritten it in javascript as a webapp running through the entertainment system already.
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