Car And Driver Results: BMW i3 Versus Mercedes-Benz B-Class Electric Drive Comparison Test

AUG 19 2014 BY MARK KANE 37

Mercedes B-Class Electric Drive & BMW i3

Mercedes B-Class Electric Drive & BMW i3

Car And Driver released interesting test results of two electric cars: BMW i3 and Mercedes-Benz B-Class Electric Drive.

As it turns out, both cars can accelerate to 30 mph in 2.7 seconds. However, the i3 is quicker to 60 MPH, but the electric Mercedes has a higher top speed of 101 mph.

It is worth noting that the B-Class ED has a lot of highway power behind it, and is considerably quicker from 60mph to 90 mph. (9.9 seconds vs 7.9 seconds)

The much lighter BMW i3 stop in less distance than the M-B..

Estimated range as tested for Mercedes-Benz B-Class Electric Drive stands at 84 miles, several percent above 79 miles for BMW i3.

And there are sound level measurements, indicating that the Mercedes is quieter (typically 3 dB is something that humanoids experience as a change of one “degree”).

In the second part, we see non-technical results showing a win by BMW i3, but with just a slight advantage. i3 has been recognized as more fun to drive, and with better performance, steering feel, brake feel and handling.  However, the electric Mercedes offers better comfort and more space. i3 leads in terms of design and finish too.

What these results mostly show us is that the vehicles are near evenly matched.  So, choose the one that’s right for you

Results From Car and Driver Put BMW i3 On Top

Results From Car and Driver Put BMW i3 On Top

Categories: BMW, Mercedes

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37 Comments on "Car And Driver Results: BMW i3 Versus Mercedes-Benz B-Class Electric Drive Comparison Test"

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Of course the weighing of each category is highly subjective so even if the assessment for each was not (it is) the grand total seems meaningless. Hey, everyone likes points and high scores. 😉

It would have been great if the comparo included a wider range of similarly sized EVs with an 80 mile or so range such as the Focus EV and the Leaf.

The one right for me? Neither in this category.

Exactly right. That weighting, what economists call each consumer’s “utility function” is both critical and highly personal.

For me, looking at how I use the vehicle that would replace my old Scion xA, my comfort level with price, my desire to minimize my carbon footprint (taking into account my use of virtually zero carbon electricity), etc., leasing a Leaf was the right choice. But that’s just me, as the saying goes, and I’m sure for other people, including a few I know beyond this site, a Volt would be the only logical choice.

Such product comparisons, especially when they involve such complex items, can still be useful as a source of (hopefully) unbiased test results.

1,082 lbs. that’s nearly the weight of an entire Model S battery pack (on top of the 28kWh useable battery that’s already in the car)

62% greater efficiency. That’s either impressive or embarrassing, depending on which side you’re viewing it from.

I’m pretty sure that the B-class has a lot more room inside (plus a 5th seat) and larger frontal area. Pretty amazing that it was faster 50-70 than the much lighter i3.

Interesting that C/D got 97 MPGe in the B-Class, and the i3 only had a 26% efficiency advantage.

My view is that EVs are so damn efficient that it doesn’t really matter. MB spent more on a big battery pack, while BMW spent more on CFRP. Same price, but MB wound up with more range.

If only MB included fast charging.

The interior space of the i3 isn’t much smaller than that of the B class, but I guess the B class has a bigger trunk.
I don’t give rats ass about the bigger front of the B class, you can’t use it for anything 🙂

Very good, but
Missing cost comparison,and energy consumption

I’ve seen a few i3s on the road and am always surprised at how small they look in real life, as compared with the pictures.

Off topic, I noticed that Kia put up a huge billboard on the 405 in LA yesterday for the Soul EV. Is that now on sale?

The results are flawed, here’s how. C/D rates the i3 at 79 miles and the MB ED at 84 miles yet in the scoring results, the i3 scores 10 while the MB ED scores 5 !!!

How is that possible? The EV that has less mileage scores tops at 10 points while the one that has more mileage scores half as much???

Therefore, using C/D results, if we were to reverse the scores and award the MB ED 10 points and the i3 5 points, the MB ED would win 203 to 201. Go figure!!

C&D’s EV tests aren’t very good. Most of the time they’re weighted strongly in the “fun to drive” category, because that’s what their readers want.

Good catch!


Mileage usually refers to the fuel economy not the range

Yes, but this is where C&D misses. Watts are cheap, and utility is all about range. We’d all poll with a majority picking the better AER, over efficiency.

C&D doesn’t do real world miles, for its tests. I haven’t driven i3, but the MB doesn’t seduce one to “hit it”. No place have I found what people are getting for B-class range. It is kind of sad, but the car doesn’t seem to be moving much. Maybe its drivers don’t share that ‘electronaut’ enthusiasm.

Probably because it’s uglier than a Leaf and an i3, and that’s saying something.

Normal looking not for you?

My wife describes me as “normal enough” all the time. I guess it’s a compliment.

I think it is pretty shortsighted to dismiss the importance of efficiency. After all, this has a direct impact on the CO2 footprint of the car as long as the majority of electricity is produced from non-renewable resources.

Also, in many countries (such as BMWs home market) electricity prices are significantly higher than in the US. Finally, if and when EVs are adopted by the mass market, demand and bottlenecks in electricity supply and distribution will almost certainly drive the prices up.

On the other hand, the few miles difference in range seem pretty immaterial to me (even more so given that BMW has the optional range extender).

No matter how wishful we might be, range gets people to move over to EV’s, from ICE, and that’s a win for the environment. That’s the prize, right now.

I think Short-sighted is when people think short, like the CO2 difference between 84MPGe and 124MPGe. At the U.S. electric mix, the MB is about .06 pound more per mile. Big deal. Gas cars emit about .50 pounds more than either of these two, every mile.

The typical gas driver, who might understand range, but who doesn’t get flu-stack and E&P emissions, won’t buy a car that doesn’t deliver enough miles. He’ll simply stick with gasoline. MPGe won’t matter to him. So, I cheer on range.

I’d say, The REx i3 will do more, for CO2, than BEV i3’s and let you come up with why I think that is so. Hint, it’s akin to Volt miles exceeding Leaf miles.

Well, if you think that >25% efficiency gain is “not a big deal”, I don’t know what to tell you. Of course it is a huge deal at fleet level. And if you find 84 instead of 79 miles range something to “cheer on”, you seem to be easily amused. In the real world, if 79 miles are insufficient, it is unlikely that 84 miles drastically improve the situation. Having the ability to occasionally add 80 miles of range in minutes at any gas station, on the other hand, goes a long way to remove people’s range concerns and will thus help the adoption of EVs.

Until such time as affordable BEVs can deliver the same range as ICEs in all weather conditions over a period of a decade or more, neither mainstream consumers or even most EV enthusiasts will give a rat’s ass about efficiency, because any EV is far more efficient and cheap to run than any ICE.

A Model S is a relatively inefficient BEV, but it’s also the one with the most utility and flexibility due to the range provided by its large and heavy battery. Only when ICE-comparable range is achieved and PEVs are mainstream, will comparative BEV efficiency matter to most people.

It isn’t just me, FFY. In the same way buyers and fleet managers focus upon mpg, to save money, they will focus on range. Swapping a gas mile for an electric mile, which generally costs one third as much, is where behavior changes. And the Mercedes Benz B-Class features 87 EPA miles of range, vs. the 81 of the BMW (non-Rex), before using an additional 6kwh of depth from a much larger Tesla battery. ~104 miles is not a small range difference.

BMW has gone on about how much more efficient their electric drive is. It is more efficient, and that’s great, but it saves its owner that 25% on electricity, not gas. To save an owner that 200% extra they have to pay for their gas miles, you need to focus on range. Even better, if the focus is on both.

“It is all about fuel economy not range.”

LOL. That was then (ICE), this is now (EV).

C&D has not adjusted yet.



I think the 10 for i3 was based on its wonderful MPGe rating.

C&D is applying old metrics to a new products. Due to the cost of gasoline MPG is an important factor for ICE vehicles, but for EVs range trumps MPGe any day.

Apparently they decided that ‘mileage’ was fuel economy and they didn’t really score range. And yeah, they SHOULD score range . . .although they are not far apart. Range is much more important for EVs since electricity is cheap.

The ‘Range Plus’ MB’s haven’t been delivered, and feature about 28% more range (104 miles) vs. the i3’s 81. Of course, that can’t be verified until they get here, but it shouldn’t be too hard to do with 33 vs. 18kwh.

I would have rated Rebates for both as a 5, since they are both eligible for a $7500 federal tax credit. Actually, maybe rate the i3’s as lower since their lease does not provide the full value.

I am also curious about the sounds at Idle rating. Both of my electric cars (Rav4 and Volt) make no noise at idle except outside traffic.

They are getting much faster 0-60 times than what I’ve seen stated on the interwebs. I think their method may be off?

Agree with kdawg the numbers seem odd. Two cars with basically the same HP and the one which is a thousand pounds heavier goes as fast 0-60 as the one which is 1000 pounds lighter. Really?

Could it be due to the thinner tires having less grip?

The Merc has a lot more torque (251 lbs ft vs. 184 for the i3) and the much larger battery probably allows them to pull the juice from it that much harder. Add in more aggressive throttle mapping and you’ve got better acceleration. I haven’t test driven the B class (not in Texas yet), but when I test drove the i3 I noticed it had that same soft hit on initial acceleration that my Volt has.

“soft hit”, exactly. The MB rolls out like all EV’s but the hit is harder, than Volt for instance. I’m 6′, and can say it is bigger in person. The roofline was higher than my chin. In visiting BMW, the interior space difference is obvious, especially in the back. People will think I’m vein, and its irrelevant, but the Harmon Kardon system is much better than Bose (goes w/o saying?). The head rest adjusts up/down, forward and back, an EV first!

No electric car ever uses all of the talk from the second you hit the pedal. They all have some sort of software control to stop you spinning the wheels uncontrollably. I suspect the BMW will have an amazing array of settings that you can adjust and play with to optimize it.

Interestingly I drove an early i-MIEV and if you took a corner quickly (well as quickly as you can in an i-MIEV) and applied the accelerator you could get the back end to step out. The car was fitted with all sorts of data loggers and sensors so I couldn’t explore this feature to its full potential but I suspect it could be quite good fun especially on a slightly damp road.

As for why they got different 0-60 times here compared to other places I am not sure but I think if you let all the talk out and limit it with the traction control you could have more fun in an electric car than we are currently permitted to have in commercially available BEV’s.

The results might have tilted towards MB had C/D factored in the upgraded range option. That is a BIG deal in my book, to be at 100 miles vs 85. Not saying I don’t think the I3 is a great car, just that for most EV drivers range is quite important.

Smart ED

0-30 – 3.1 Seconds
0-60 – 7.8 Seconds

According to the C/D EV comparison,

Smart ED:
0-30mph: 3.1 sec.
0-60mph: 9.8 sec.

You are off by a good 2sec in 0-60mph.

too bad both the cars are unattractive

I’m glad to see the 0-30 time included. As more EV’s start appearing I would hope to see a category for 0-50. My BMW Active was extremely fast to 30 and pretty quick to 50 and much quicker than the 0-60 time would have indicated. For real world street driving EV’s are much faster.

As a general statement, I think it is fair to say that most people are concerned with:
1. Vehicle size/practicality
2. Range
3. Cost

Appearance, handling, stereo, efficiency, etc., are much further down the list.

Here, the i3 is a smaller “city” type car, and the MB is clearly a conventional car. The MB has greater range — unless you get the i3 Range Extender, which really changes the equation (and probably by C&D gave the i3 the significant nod in that category). Cost appears to be fairly close and so not a factor.

BTW: I disagree with the C&D assessment re MC range — I bet at 100% charge it is more like 110 miles to true empty.