BMW i3 REx vs Chevy Volt: My Take

The Challenge

Last week I was contacted by High Gear Media Senior Editor, John Voelcker and asked if I had interest in doing a head to head comparison piece between my i3 REx and a Chevy Volt. Green Car Reports contributor David Noland (who happens to own a Volt and a Model S) wanted to pit the Volt against an i3 REx and asked John to reach out to me and find out if I was up for it.

I liked the idea of swapping cars and driving side by side for a few hours and that met David's needs as well. David wanted to do an efficiency test and measure the miles per kWh's used driving 15 to 20 miles in a city environment, and then do the same thing at highway speeds of 65 to 75mph. Going in, David expected the i3 to be more efficient in the city driving test, but the Volt to be more efficient on the highway test where weight plays a lesser role and aerodynamics are more important. The i3 is tall, has a large front area and is a bit boxy compared to the Volt. This creates a much higher CdA which will lower the i3's efficiency at high speeds. Having driven my i3 for a while now, I knew it would be more efficient in the city cycle, but I figured it would probably tie the Volt on the highway leg of the test. My i3's life time efficiency so far is 4.5 miles per kWh and I do at least 50% of my driving at highway speeds.

David averaged 4.1 miles per kWh over a 46 mile drive at highway speeds. This was driving about 15 miles in charge depleting mode and another 31 miles with the range extender running.  The display only shows an average speed of 56.7mph, but much of the trip was done at 70+ mph

David was also very interested to find out how the range extender performed. In my opinion, the i3's range extender is largely misunderstood. Even months after the launch, few people really understand how it works, what it can and cannot do. It has been called everything from a "limp mode" to an "emergency use only" option, and quite honestly BMW hasn't done itself any favors by not fully explaining how it works and how to use it properly. I promised David he could drive it as he wished, and even purposefully overwhelm the REx by driving fast enough to use more energy than the range extender could produce, should he desire to do so. At one point he even asked if I minded if he did just that, but due to the other traffic we couldn't really sustain a speed much over 70mph for long and we were not going up and long, steep inclines so the REx was able to put out enough power to maintain the SOC between about 4% and 6%. In short, we couldn't overwhelm it without driving in a an unsafe manner.

Getting ready to take off from Nauna's Bella Casa in Montclair

There aren't many long climbs in my area and I've driven with the range extender on quite a bit. I haven't found any condition where it isn't perfectly capable of allowing me to drive as long as I needed to, including hundreds of miles if I really wanted. However I know the REx has its limits, unlike the Volt. I have heard stories of people not being able to maintain highway speeds as the car drops to 45 mph suddenly. That's a problem that BMW needs to address. I think they need to make a better effort to communicate to the customers what the limits are, and I also believe the customer needs to be cognizant of the limits and keep an eye on the SOC under high speed driving up long inclines. It's not a do-all-under-any-condition vehicle. The range extender has limits but I definitely believe that for the vast majority of people it will do just about anything they need. Also, since the i3's electric range is double that of the Volt, the range extender will be used much less, so it's reasonable to understand why it is less robust.

People are surprised when they see the i3 next to other EVs. It is larger than I believe many people think it is.

On the Road
 
I felt very comfortable behind the wheel of the Volt as I've driven many of them and have always liked the driving experience that they offer. However, this was the first time I've driven a Volt since getting my i3 REx three months and about 6,500 miles ago. The two cars definitely feel very different. The much heavier Volt absorbs road irregularities better and is quieter at high speeds, where the boxy i3 has noticeable wind noise. The i3 is much quicker, especially at higher speeds and has better braking and handling. The i3's steering is more direct and sensitive and the Volt's brakes seemed a little spongy or squishy compared to what I'm used to in the i3. The i3 is clearly more of a performance car, while the Volt offers a more supple, softer ride. The regenerative braking on the i3 is much stronger than the Volt's, even in Sport mode and low driving gear. I'm sure I would adjust to it if I had a Volt for awhile, but I just couldn't get myself to stop for traffic lights without needing to depress the friction brake pedal every time. I almost never use the friction brake pedal on my i3 unless it's an emergency situation where I need to slow down unexpectedly. I really love this on the i3, and haven't found any other EV to have a regen system that matches it. It's definitely one thing that BMW got right. I know the Volt blends regen with friction braking so I suspect most of the time I depressed the brake pedal I wasn't even using the friction brakes, but I've really grown fond of the one-pedal driving of my i3 that anything else now seems sub-standard.

The interior of the Volt

The interior of the i3

I found both cars comparable in seating comfort and room, with the Volt having a larger cargo area. Because the e-drive motor and range extender are under the deck behind the rear seats, the i3's cargo deck is higher, which cuts down on the cargo space, but it also doesn't have a tailgate lip so you can slide objects in and out without having to pick them up over the lip to remove them as is the case with the Volt, which my bad back appreciates. Personally I like the uncluttered, modern interior look of the i3 better, and the large center display probably is the nicest I've seen in any car besides the Model S. However the exterior styling of the i3 is definitely unconventional and I'm sure many people will say they like the look of the Volt better, but styling is subjective so I'm not really going to get too caught up appearance here. One thing I really do like in my i3 is how the absence of a center transmission tunnel (battery tunnel on the Volt) provides a much more open, spacious feel in the cockpit. In fact, this makes it quite easy to slide across from the drivers seat and exit from the passengers door if you want to.  

The Volt has a larger cargo capacity, but with the rear seats folded flat, the i3's cargo space is definitely adequate for my needs.

Efficiency

David really wanted to focus on the efficiency of the cars so we did roughly 15 miles of city driving, followed by 15 miles of highway driving at 60 -70 mph. There were a few occasions we got up to 75 or so to pass other vehicles but for the most part we drove in the middle lane and averaged a little under 70mph. In the city cycle the i3 averaged a 5 miles per kWh used compared to the Volts 4.5. The Volt did better than I expected in this part of the test though, which I am happy to report. On the highway test the i3 delivered  4 miles per kWh used and the Volt averaged 3.5 mi/kWh. David and I were both surprised that the i3 actually had a larger advantage on highway driving than it did in city driving, but was 14% on the highway. I suspect if we drove faster, and averaged over 70 mph, the Volt would have caught the i3 in efficiency. The test also isn't perfectly controlled, since David and I aren't the exact same drivers. However, we are both very experienced electric vehicle drivers, and understand perfectly well how to maximize efficiency with the use of regenerative braking and limiting jack-rabbit style take offs. We drove with the climate controls set to 72 degrees and the windows closed.

During the city driving test. I jumped out of the Volt at a red light to grab this picture.

Conclusions

Having had quite a bit of previous experience driving Volts, there were really no surprises for me. I have always liked the Volt, and nothing from this experience has changed that. It's a very capable extended range electric car that offers a good ride, decent performance and nice styling. It is a better choice for long range driving (over 200 miles) and definitely if you live in a mountainous area. I can't even count how many people I've recommended the Volt to; and many have stopped back to my restaurant weeks or months later to show me that they took my advice. With a starting price of $34,999 it's a really a great deal. The i3 REx on the other hand starts at $46,125 which is $11,000 more. Yes, you do get a more nicely optioned vehicle but it's very hard to ignore the $11,000 difference. If price is a big consideration then it's hard not to pocket the eleven grand and take home a Volt.

However buying a car isn't always a rational decision, and there are indeed emotions involved. If that weren't the case we'd all be driving $15,000 Honda Fits. There are a lot of reasons why the i3 REx is a better EV for me than the Volt. First off, I drive about 33,000 per year, and the 38 mile AER of the Volt would mean I'd be driving on gas about as much as I drove on electric. The i3 REx will allow me to drive on electric over 90% of the time. For me to increase that 100% I'd need to jump up to Model S-type range because the times I have needed the REx were usually 150 to 200 driving mile days and there are no other current production electric vehicles capable of doing that without using a robust DCQC network which doesn't yet exist in the Northast. Another consideration is the 3.3kW onboard charger that the Volt has. I'd find it very hard to buy any EV that was limited to 3.3kW charging. My i3 can actually charge faster from zero to full an a level 2 EVSE than a Volt can, yet it has twice the electric range. GM absolutely needs to upgrade the onboard charger to a minimum of 6.6kW for the next generation Volt in my opinion.

I've read many comments on various online forums regarding the size of the i3's gas tank and I can say I categorically disagree with the notion that the car needs a larger gas tank. In fact, I'd be fine with a smaller one. If you think you need a bigger gas tank on the i3, then what you really need is a Volt because you're buying it for a use that it's not really intended for. The i3 REx is fine for driving in range extender mode for short distances, and I think it's really a great car for trips up to 150 miles or so, but if you really need to frequently drive more than that, it just may not be the best fit. If you need to go further once a month or so, then sure that shouldn't be a problem as long as you don't mind the 2-3 minute stop to refill the tiny tank, but frequent long distance driving just isn't the car's best use.

I also put a big emphasis on the driving experience and the i3 is really a blast to drive. The Volt is fun in its own right, and it is certainly no slouch by any means, but the i3 is noticeably faster and has a much more direct steering feel. I also love the fact that the i3 is all carbon fiber reinforced plastic and aluminum, the open cockpit and simple dashboard with the large center display. It was indeed the better choice for me, but honestly, I would be very happy driving a Volt also, especially if I drove less than the 90 miles a day that I do now. I don't think you can lose with either of these extended range EVs. Just pick the one that fits your budget, needs and desires and you'll be happy with whichever you choose.

You can read David's thoughts on his Green Car Reports article here.

After 2,000 Miles: The Likes

Now that I've had my i3 for nearly a month, I'm starting to get a good feel for what I like and what I don't. My initial thought was to do one post with both the likes and dislikes at this point, but after assembling the lists, I realized I wouldn't be able to spend enough time on each topic if I did it that way. Therefore I decided I'd do two consecutive posts, with one for the likes and one for the dislikes. I'm tackling the easy one first, the likes:


Adaptive Cruise Control With Stop & Go: This feature is really useful. It's kind of like locking in on the vehicle in front of you with a tractor beam and letting it pull you along. I've found it great for both low speed and high speed driving and the car will even come to a complete stop and accelerate again once the car in front of you does. The only things that aren't perfect is I've found it sometimes leaves too large of a gap in between you and the car you are chasing (for safety reasons I guess) but that allows people to easily cut in front of you if they want to. Also, some times it disengages for no apparent reason and when it does that, the car goes into full regenerative braking mode, since you don't have your foot on the accelerator. It seems to do it more in the rain and also when approaching overpasses. Both could possible confuse the camera-based system. That is not an ideal situation by any means, and something I hope BMW will address with a software update in the future. If the adaptive cruise control does disengage by itself, the car should temporally suspend the regenerative braking until the driver touches either the brake or the accelerator themselves. 

This display appears when the adaptive cruise control system automatically disengages

Seating Position: Like many things in any "likes & dislikes" list, this is highly subjective. The seating position in the i3 is very high, and really "un-sports car like". It's actually like sitting in a mini SUV. I like this position and really like the outward vision you get in the car, with lots of glass surfaces and an absolutely huge windshield. The only thing I had to get used to was that you cannot see the nose of the car at all. The hood drops off so prominently, it's impossible to see it from inside the car. After a week or two I was past that though, and feel totally comfortable with not being able to see the nose at all.

The high seating position and the abundance of glass allow for a great outward view

Charging Rate: One of the advantages of having a small battery in your electric vehicle is that it will charge quickly, provided it has a robust onboard charger. The i3 is supposed to be able to accept up to 32 amps @240V which would be about 7.7kW. I haven't seen my charge rate quite that high, but I do seem to be pulling about 6.9kW from my home EVSE. That's good enough to refill a fully discharged battery in about 3.5 hours, or give me roughly 25 miles of range per hour of charging. My ActiveE took about 5 hours to fully charge when it was new, and then when BMW lowered the charge rate due to onboard charger problems, it was taking nearly 7 hours to fully charge. My i3 charges in about half the time it was taking my ActiveE and that makes such a difference for someone like me that does a lot of driving.

Charging at home. The quick charge rate has allowed me to drive 120+ electric miles in the same day without the need of the REx a couple times already.

Cargo Space: For the past five years I've been driving BMW's beta test electric vehicles which were converted gas cars. Both vehicles had severely compromised cargo areas because they were conversions. I use my car to run errands for my restaurant and I'm frequently picking up various supplies. The hatchback cargo area of the i3, especially with the seats down is so much more useful than either the MINI-E or the ActiveE was and I'm so happy to finally have a real purpose built electric vehicle. The battery packaging doesn't interfere with any of the passenger or cargo space, as it's located directly beneath the passenger compartment in one large aluminum case. As much as I liked my previous EV's, the fact that they were indeed conversions did limit their utility.

Delivering a catering order

Picking up some supplies

The Interior: If the unconventional exterior styling has some people scratching their heads, just tell them to open the doors and take a seat inside. The interior is stunningly beautiful, with well laid out instruments and more space than a car of this size ever deserves to have. The tall body and wide stance allows the i3, which is more than a foot smaller than a 1-Series to have nearly as much interior space as a 3-Series. The huge 8.8" center instrumentation screen is amazingly clear, and somehow doesn't have a glare problem as I feared it may. The seats are comfortable and the armrest is adjustable so you can set it at the height you prefer. There is plenty of space to store stuff with huge door pockets, each that will hold two beverage bottles. There are two cup holders between the rear seats and two cup holders in the front with a slot for another optional cup holder. In all the car has up to nine beverage holders. I thought German engineers didn't understand the American obsession to hold drinks in the car?

The "Tera World" interior of my i3

The Efficiency: The i3 is the most efficient passenger car available in the US. So far, according to the data I'm compiling it's nearly 25% more efficient than my ActiveE was. That means I'm using 25% less energy that the ActiveE which was a pretty efficient EV in its own right. I actually did a blog post last week on the subject of efficiency which you can view here.

If you can curb your enthusiasm for the instant torque, the i3 can be an extremely efficient machine

Comfort Access: OK, so this isn't really anything related to it being an electric vehicle, but it's the first car I've owned with this feature. You just walk up to the car with the key in the pocket and it unlocks when you grab the handle. Then get inside and just press the start button and it turns on. When you leave you just touch the door handle in a particular spot and it locks. The only thing I don't like about this, which will definitely be mentioned in my "dislikes" post, is the extremely loud beep the car makes when you lock or unlock the doors. It's ear-piercingly loud and makes everyone in the general vicinity look your way. Update: It was pointed out to me in the BMW i3 Facebook group that you can disable the beep which I just did. For those wanting to do the same, it's in Settings>Doors/Key>Acuoustic sig.Lock/Unlock. I believe the base model (Mega World in the US) doesn't have the beep feature, but Giga and Tera Worlds do, and you can disable it there.

The Range Extender: I was on the fence for a long time trying to decide whether to get the REx or not. Once it became evident the BEV i3 wouldn't have a real 100 mile range that I could depend on, the REx really became a necessary decision. I'd prefer having a 100 mile EV and a good robust fast charge network, but that will take a few more years, at least here in the North East. For now, the range extender concept works perfectly for me. When I first got the car I purposely didn't charge it so I could fully test the REx performance and it worked even better than I imagined. I did about two hundred miles of driving in REx mode, mostly highway driving at 70 to 75 mph and it was perfectly capable of maintaining the charge. I still haven't had time to really test it by overworking it until it cannot sustain the charge, but I will. The good news is that I'll have to actually try to do that, because it is definitely robust enough to do anything I'll need it to, and that includes 230 mile trips to Vermont. I drive about 30,000 miles per year, and I'm guessing I'll do about 1,000 miles with the REx running. The one great thing about the REx is not having to think about where I'm going in order to make sure I can plug in if I need to drive a little farther than planned. I believe in the near future the range extender won't be necessary, but with where battery tech and charging infrastructure is today, I believe it makes sense for a lot of people and will certainly help with the adoption of electric vehicles.

The i3's range extender sits next to the electric motor above the rear axle.

Collision Warning: Collision Warning with Brake Priming Function is activated at speeds up to 35 mph. It  is able to respond to both moving and stationary vehicles ahead, as well as to pedestrians. If you are rapidly approaching a vehicle or pedestrian, it offers a audible warning and "primes" the brakes so they are ready for the moment you depress the brake pedal. BMW claims this allows for shorter stopping distances. What I really like though is the audible alert. I've only had it come on twice so far and in neither time did it actually prevent me from having a collision, but I could definitely see it doing just that under certain circumstances (like distracted driving). It's definitely a neat safety device and one that I hope all cars have some day.

Hill Hold: If the BMW engineers that are responsible for the hill hold on the i3 are reading this I'd like to say something: Bravo! You nailed it! Electric cars will roll freely forwards or backwards like manual transmission cars do. For the ActiveE, BMW employed the same kind of hill hold feature like they do on their conventionally-powered cars. You needed to depress the brake pedal to activate the hill hold feature, and it would release in a couple seconds. It wasn't bad, but it wasn't perfect either. The i3 won't roll backwards at all unless you put it in reverse, and you don't need to depress the brake pedal to activate the hill hold, it just does it automatically. However it will roll forward to assist in your launch, which is the way it should be. The hill hold feature doesn't time-out, and holds the vehicle as long as you need it to. This seems so natural when you drive it, and now that I've experienced it I'm wondering why no other electric vehicle manufacturer has come up with this yet. I'm sure they will copy it though.

Soft Speed Limiter: This is another feature that I believe is unique to the i3 and is pretty innovative. Perhaps the biggest range thief with electric vehicles is excessive speed. The i3 employes a unique soft speed limiter to gently remind you that you are driving fast and perhaps you should consider slowing down to extend your range. There are three driving modes in the i3: Comfort (this is what the car defaults to) Eco Pro and Eco Pro +. There is no soft speed limit in Comfort mode, but while driving in Eco Pro and Eco Pro +, the soft speed limits are at 75mph and 55mph respectively. The reasoning behind this is if you are in comfort mode, you likely have plenty of range and aren't consciously concerned with extending it. However if you selected Eco Pro or Eco Pro +, you likely are concerned with how much range you have and are making an effort to maximize it. Since driving fast is very inefficient, the car coaches you a bit and "reminds" you that you may want to slow down. Here's how it works: When you reach the speed that the soft limit is set at (75 mph  for Eco Pro and 55 mph for Eco Pro +) the car will not exceed that speed, even if you continue to depress the accelerator. In order to go faster, you need to continue to depress the accelerator further and after a couple seconds it realized that you are aware that you're passing the soft limit but wish to do so anyway, and it will indeed accelerate. It actually takes off rather quickly with an abrupt burst of speed at that point, almost as if to say "Well you asked for it!" I really like this "coaching" feature. There have been plenty of times in my other EVs that I was driving on the highway and wanted to keep my speed down a bit to conserve energy but would find myself creeping up and driving faster than I wanted to without noticing it. With this feature, you really won't pass the soft limit without really intending to, you can't do it by accident.

When you activate Eco Pro +  mode, you get this display prompting you to keep your speed under 55 mph for maximum range. This lead some people to assume it meant the car wouldn't go faster than 55 mph in this mode, which is not correct.

Acceleration: I saved the best for last. The i3 is really a blast to drive. I have the REx i3 which is about a half a second slower than the BEV and have been timing myself from 0-60 in around 7.6 seconds. It's not Tesla fast, but it is a really a quick little car and is much faster and more fun to drive than my ActiveE was. The instant power in the 10 mph to 50 mph range is amazing and feels quicker than my Porsche Boxster did when accelerating at those speeds. This is indeed a fun car to drive, and drives so much better than anyone would expect just from looking at it.