[BlackBeamer80]

When running in electric mode on the 50e, does it operate in AWD or rear wheel drive?

[TurtleBoy]

AWD

[nZtiZia]

Originally Posted by BlackBeamer80

When running in electric mode on the 50e, does it operate in AWD or rear wheel drive?

BMW's xDrive system is AWD (as already mentioned). in all drive modes under normal conditions (not just electric mode), it has a 60:40 rear:front bias that changes quickly as the road conditions warrant.

[jad03060]

The EV motor is IN the transmission case, so the drive train remains exactly the same...it's just clutches that decide which motor or motors are in use driving the vehicle. When using the ICE, there are clutches on the front and rear of the EV motor that are open. When the EV motor takes over, it disengages the drive shaft from the ICE, or can close both ends and let both motors propel the vehicle through the same drivetrain.

[ScaldedDog]

/\ My favorite thing about the 45e. You don't have to care whether it's running on gas, electrons or unicorn tears. We can fill it up when it needs it, plug it in when we get home, and just drive the thing.

Mark

[aaaaaaaaaz]

Yes.

You can open "live car > xView" to see the real-time power split to front/rear axis.
(see this video

at 1:22)

What I observe is it shows more closer to 0/100 on normal chill drive, and closer to 40/60 when quickly accelerating especially from stop, regardless of using ICE or electric.

[nZtiZia]

Originally Posted by alanzyy

You can open "live car > xView" to see the real-time power split to front/rear axis.
…
What I observe is it shows more closer to 0/100 on normal chill drive, and closer to 40/60 when quickly accelerating especially from stop, regardless of using ICE or electric.

interesting. sources on the xDrive system and all logic regarding torque would have those values reversed: 40F/60R under normal conditions, 0F/100R when quickly accelerating

[jad03060]

A study done ages ago by Audi found that the losses from friction and drag in a typical all-wheel drive system were not significant with theirs. Now, one can suspect that it is biased, but their reasoning said that a 'pushed' wheel caused more friction and thus drag than one that was powered, thus 'pulling'. A pushed (or pulled) wheel is always trying to go uphill slightly to overcome the deflection caused by the weight on it. Audi claimed their all-wheel drive system was thus more efficient than a F or R wheel drive system.

Anyway, as was said, the PHEV doesn't change operations about all-wheel drive based on which motor is providing the propulsion unlike some that put the EV motor on an individual axle, and the ICE on the other. Balancing that situation is a little tougher, too.

[eelnoraa]

Originally Posted by nZtiZia

interesting. sources on the xDrive system and all logic regarding torque would have those values reversed: 40/60 under normal conditions, 0/100 when quickly accelerating

I think acceleration is always the best to put all power to RW unless RW is slipping.

[cobramite]

Originally Posted by jad03060

A study done ages ago by Audi found that the losses from friction and drag in a typical all-wheel drive system were not significant with theirs. Now, one can suspect that it is biased, but their reasoning said that a 'pushed' wheel caused more friction and thus drag than one that was powered, thus 'pulling'. A pushed (or pulled) wheel is always trying to go uphill slightly to overcome the deflection caused by the weight on it. Audi claimed their all-wheel drive system was thus more efficient than a F or R wheel drive system.

Anyway, as was said, the PHEV doesn't change operations about all-wheel drive based on which motor is providing the propulsion unlike some that put the EV motor on an individual axle, and the ICE on the other. Balancing that situation is a little tougher, too.

Interesting and makes good sense.

[aaaaaaaaaz]

Originally Posted by eelnoraa

I think acceleration is always the best to put all power to RW unless RW is slipping.

This seems consistent with what I see from the xView - normal time put all power to RW; in acceleration/cornering less than half goes to front. Let me try to take a video tomorrow.

[nZtiZia]

Originally Posted by alanzyy

…
What I observe is it shows more closer to 0/100 on normal chill drive, and closer to 40/60 when quickly accelerating especially from stop, regardless of using ICE or electric.

Originally Posted by alanzyy

This seems consistent with what I see from the xView - normal time put all power to RW; in acceleration/cornering less than half goes to front. Let me try to take a video tomorrow.

I’m confused. in your first post, you said 0/100 F/R on normal chill drive and 40/60 F/R when accelerating, so I replied it should be reversed: 40/60 on normal chill drive and 0/100 when accelerating

Originally Posted by eelnoraa

I think acceleration is always the best to put all power to RW unless RW is slipping.

I agree, but he said he sees 0:100% rear bias during normal chill driving and 40:60% rear bias when accelerating

[jad03060]

The logic looks for slip, and shifts drive accordingly.

[aaaaaaaaaz]

Originally Posted by nZtiZia

I’m confused. in your first post, you said 0/100 F/R on normal chill drive and 40/60 F/R when accelerating, so I replied it should be reversed: 40/60 on normal chill drive and 0/100 when accelerating

I agree, but he said he sees 0:100% rear bias during normal chill driving and 40:60% rear bias when accelerating

Not sure what you means, but what I observe seems to be consistent with what eelnoraa is suggesting and different from what you suggest

[aaaaaaaaaz]

Took a short drive and recorded the xView screen. Apologize for poor video quality.

At the beginning of video and at 00:45 - accelerating from stop sign, xView shows more of a 40/60 split.

During other time / normal driving it seems all power goes to rear.

[nZtiZia]

that was very helpful. i understand now, thanks!