Official Mercedes B-class EV thread

[Devin]

That issue they are having sounds a lot like the RAV4's "Check EV System" error that can be mostly ignored by the driver or reset. The solution for most people has been a firmware update. Sounds like there's a Tesla issue at the heart of this problem in both the RAV4 and MBED where Toyota/Mercedes' computer just spazzes out when it gets encountered.

 

[edatoakrun]

About the same size as a LEAF, yet the B class requires 40 kWh to get the EPA-combined-cycle-100-miles the LEAF does on 30 kWh?

I attributed the relatively poor efficiency of the Tesla S and RAV4EV to be due to their overweight/oversize designs.

But the weight alone (~600 lbs more than the LEAF) of the B-class could not seem to account for it's relatively poor efficiency.

The results of all three of the Tesla drivetrains in the city and the highway cycles seem to indicate less efficient operation (especially in regeneration) not only as compared to the LEAF, but also to the other compliance BEVs.

You can use the tool below to get the EPA test results for all US market BEV/PHEVs.

http://fueleconomy.gov/feg/Find.do?action=sbs&id=35247&id=34699&id=34425&id=34775" onclick="window.open(this.href);return false;

 

[GRA]

About the same size as a LEAF, yet the B class requires 40 kWh to get the EPA-combined-cycle-100-miles the LEAF does on 30 kWh?

I attributed the relatively poor efficiency of the Tesla S and RAV4EV to be due to their overweight/oversize designs.

But the weight alone (~600 lbs more than the LEAF) of the B-class could not seem to account for it's relatively poor efficiency.

The results of all three of the Tesla drivetrains in the city and the highway cycles seem to indicate less efficient operation (especially in regeneration) not only as compared to the LEAF, but also to the other compliance BEVs.

I wonder how much if any of the difference is due to the use of AC induction motors. ISTR the LEAF uses a synchronous motor?

 

[lorenfb]

About the same size as a LEAF, yet the B class requires 40 kWh to get the EPA-combined-cycle-100-miles the LEAF does on 30 kWh?

I attributed the relatively poor efficiency of the Tesla S and RAV4EV to be due to their overweight/oversize designs.

But the weight alone (~600 lbs more than the LEAF) of the B-class could not seem to account for it's relatively poor efficiency.

The results of all three of the Tesla drivetrains in the city and the highway cycles seem to indicate less efficient operation (especially in regeneration) not only as compared to the LEAF, but also to the other compliance BEVs.

I wonder how much if any of the difference is due to the use of AC induction motors. ISTR the LEAF uses a synchronous motor?

The Leaf motor uses permanent magnets for the motor's rotor (exterior) and an interior stator that's pulse-width modulated. The motor is similar to the motor used in a hard drive, i.e. a D.C. brush-less motor.
The Leaf motor is more efficient and requires a less complex controller, but has less torque capability
and less max RPM than does the A.C. motor of the Tesla & Volt.

 

[jsongster]

The current B platform was designed from the get-go to be a FCV and an EV, as well as an ICE, so I think that is a no brainer...

I will bet you $100 that they bring a fuel cell to market for 2018.

The number one reason to sell the Fool Cell will be that they ONLY have to sell the car in California... if they keep with the BEV, they will be required by 2018 to sell in CARB-ZEV "coalition" states - California, Connecticut, Maryland, Massachusetts, New York, Oregon, Rhode Island and Vermont.

That's when they can step out, like Toyota and Honda (and I predict GM, probably Ford) and say, "We tried to sell the electric cars but nobody wanted them.

++1
Just like last freakin time...

 

[sparky]

About the same size as a LEAF, yet the B class requires 40 kWh to get the EPA-combined-cycle-100-miles the LEAF does on 30 kWh?

I attributed the relatively poor efficiency of the Tesla S and RAV4EV to be due to their overweight/oversize designs.

But the weight alone (~600 lbs more than the LEAF) of the B-class could not seem to account for it's relatively poor efficiency.

The results of all three of the Tesla drivetrains in the city and the highway cycles seem to indicate less efficient operation (especially in regeneration) not only as compared to the LEAF, but also to the other compliance BEVs.

I wonder how much if any of the difference is due to the use of AC induction motors. ISTR the LEAF uses a synchronous motor?

I think the motor differences are only a few percent. I don't know the composition of the EPA combined cycle test but, why couldn't nearly all of the difference be rolling resistance? If that energy consuming force can be described as F = Crr * M(ass) * g(ravity) where Crr is the coefficient of rolling resistance, I would expect cars like the LEAF and i3 to do well since they employ low rolling resistance tires as well as have the lowest mass. Seems that Crr and M are higher for both the B-class and Tesla. I don't know if the EPA test even accounts for aero drag at all so the rolling resistance portion may be the more significant effect there whereas drag is a much bigger effect at most USA driving speeds.

Normal driving with my Tesla is about 3 mi / kWh. Normal driving of my LEAF is about 3.5 mi/kWh. Anecdotal info but I don't see a big loss of efficiency with the Tesla beyond what I would expect from it being a heavier car with higher Crr.

 

[GRA]

About the same size as a LEAF, yet the B class requires 40 kWh to get the EPA-combined-cycle-100-miles the LEAF does on 30 kWh?

I attributed the relatively poor efficiency of the Tesla S and RAV4EV to be due to their overweight/oversize designs.

But the weight alone (~600 lbs more than the LEAF) of the B-class could not seem to account for it's relatively poor efficiency.

The results of all three of the Tesla drivetrains in the city and the highway cycles seem to indicate less efficient operation (especially in regeneration) not only as compared to the LEAF, but also to the other compliance BEVs.

I wonder how much if any of the difference is due to the use of AC induction motors. ISTR the LEAF uses a synchronous motor?

I think the motor differences are only a few percent. I don't know the composition of the EPA combined cycle test but, why couldn't nearly all of the difference be rolling resistance? If that energy consuming force can be described as F = Crr * M(ass) * g(ravity) where Crr is the coefficient of rolling resistance, I would expect cars like the LEAF and i3 to do well since they employ low rolling resistance tires as well as have the lowest mass. Seems that Crr and M are higher for both the B-class and Tesla. I don't know if the EPA test even accounts for aero drag at all so the rolling resistance portion may be the more significant effect there whereas drag is a much bigger effect at most USA driving speeds.

Normal driving with my Tesla is about 3 mi / kWh. Normal driving of my LEAF is about 3.5 mi/kWh. Anecdotal info but I don't see a big loss of efficiency with the Tesla beyond what I would expect from it being a heavier car with higher Crr.

You may well be right. The latest (Sept.) issue of C&D has a head-to-head comparo of the i3 and B-Class. As you'd expect from C&D they prefer the i3 for its sportiness (and ability to get people to notice it; the B is invisible in SoCal, sort of a more expensive Coda (although it probably most resembles the C-Max), but the B-Class wins out in utility and normal driving. One of the biggest differences with the B is that it uses Michelin Primacy 225/50 tires instead of the dinky LRR donuts of the i3. Even so, despite hauling around over 1,000 lb. more mass and having slightly less power, it equals the i3 in 30-50 passing time (2.5 sec.) and beats it from 50-70. The i3 is a bit faster 0-60, IIRR 6.5 vs. 6.8 sec., the B-class is faster 0 to 90 (the i3 tops out at 92 or 93, the MB at 101) and the i3 is slightly faster in the quarter mile. While I'd undoubtedly prefer throwing the i3 around, for day to day usage as a car the B seems to come out well ahead.

 

[lorenfb]

"I would expect cars like the LEAF and i3Visit the i3 Forum to do well since they employ low rolling resistance tires as well as have the lowest mass."

That's what Elon would say, as it's just basic Physics 101!

Total Energy Consumed = Motor/Controller Losses + Rolling Resistance Losses + Coefficient of Drag Losses

 

[TomT]

Update on the "Do Not Change Gears" software issue for one customer:

"Good morning. There has been nothing to report until about 10 minutes ago. Resolution from a software update is "2-3 months away" and MB is buying the car back from me. They kindly advised me to make my 1st payment due next week, and they will refund it in the buyback which takes 2-3 weeks I was told. I have been graciously advised I will not be charged for the 152 miles I drove, I will be refunded my down payment and the first monthly payment I am to make. That's it."

 

[pkulak]

Update on the "Do Not Change Gears" software issue for one customer:

"Good morning. There has been nothing to report until about 10 minutes ago. Resolution from a software update is "2-3 months away" and MB is buying the car back from me. They kindly advised me to make my 1st payment due next week, and they will refund it in the buyback which takes 2-3 weeks I was told. I have been graciously advised I will not be charged for the 152 miles I drove, I will be refunded my down payment and the first monthly payment I am to make. That's it."

Wow. That kinda sucks if you already sold your other car.

 

[TomT]

Yes, and there are reportedly a number of cars afflicted with the problem... Some customers are choosing to simply ignore the warning and continue using the cars.

Wow. That kinda sucks if you already sold your other car.

 

[nosuchthing]

Interesting it did not happen to the two engineers in that MBB "it's electric!" commercial...
It must have been that lightning as the car rose above the cave. It shorted the motherboard.

 

[GRA]

Interesting it did not happen to the two engineers in that MBB "it's electric!" commercial...
It must have been that lightning as the car rose above the cave. It shorted the motherboard.

Maybe they missed the meeting where it was discussed?

http://www.brucegray.com/images/ap1.jpg" onclick="window.open(this.href);return false;

 

[nosuchthing]

Anysing goes vrong viz your Mercedes Benz ve vill replace...
...Z DEALR!

 

[JasonA]

So how can they say in the commercial "The first BEV sold in the United States" ?? :roll:

Ummm.. no..

Really surprised you guys haven't caught on to this and griped yet :twisted:

 

[Devin]

So how can they say in the commercial "The first BEV sold in the United States" ?? :roll:

Ummm.. no..

Really surprised you guys haven't caught on to this and griped yet :twisted:

The commercial VO says it's the first electric Mercedes, and the disclaimer says it's the first BEV sold in US [by Mercedes] since Mercedes has had test EVs elsewhere.

 

[JasonA]

So how can they say in the commercial "The first BEV sold in the United States" ?? :roll:

Ummm.. no..

Really surprised you guys haven't caught on to this and griped yet :twisted:

The commercial VO says it's the first electric Mercedes, and the disclaimer says it's the first BEV sold in US [by Mercedes] since Mercedes has had test EVs elsewhere.

Just because John Hamm is saying it doesn't mean anything.. print is everything.. and it doesn't say [by Mercedes]

It's shady advertising at best.. :roll: When the average consumer sees this, what are they so assume?

 

[TomT]

Kind of like Nissan's "100 miles..."

It's shady advertising at best.. :roll: When the average consumer sees this, what are they so assume?

 

[Devin]

So how can they say in the commercial "The first BEV sold in the United States" ?? :roll:

Ummm.. no..

Really surprised you guys haven't caught on to this and griped yet :twisted:

The commercial VO says it's the first electric Mercedes, and the disclaimer says it's the first BEV sold in US [by Mercedes] since Mercedes has had test EVs elsewhere.

Just because John Hamm is saying it doesn't mean anything.. print is everything.. and it doesn't say [by Mercedes]

It's shady advertising at best.. :roll: When the average consumer sees this, what are they so assume?

If the average consumer sees that and doesn't put two and two together then I have no sympathy for them.

Nobody can reasonably argue the audio and video track are to be taken separately (otherwise it'd be either radio or print!). When I worked in film we didn't duplicate all visible and audible elements in each other form because people might not be paying attention. If people don't want to listen, they can read a book or a newspaper.

 

[redLEAF]

From the perspective of a Tesla S owner ... if MBZ ever sends me such an invitation I'll be sure to take them up on it

http://www.washingtonpost.com/blogs...sla-fanboy-meets-mercedes-benzs-electric-car/