BMW i3 REx Versus Chevy Volt – Real-World Comparison Test


BMW i3 REx Versus Chevy Volt

BMW i3 REx Versus Chevy Volt

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 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

Editor’s Note: This post appears on Tom’s “The Electric BMW i3” blog.  Check it out here.

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

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.

BMW i3 REx Versus Chevy Volt

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.

Volt Interior

Volt Interior

i3 Interior

i3 Interior

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.

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.


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.

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


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.

i3 Versus Volt

i3 Versus Volt

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.

BMW i3

BMW i3

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 in his Green Car Reports article here.

Categories: BMW, Chevrolet

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46 Comments on "BMW i3 REx Versus Chevy Volt – Real-World Comparison Test"

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As much as it pains me to say it, the BMW is much better looking in these photos than in the ones I have seen before. And all credit to them for their pioneering work with carbon fiber.

That said, it is NOT on my shopping list. “Buy American, the job you save may be your own”. End of story.

Hi Noel.

Thanks for dropping by.

Well I’m glad I tracked you down. You had me worried. I’ll be checking in with you here regularly. The array of articles is very impressive. And a big shout out to “static”.

Hey, hey Noel, good to see you, (=

/dusts off old handle

The carbon fibre for the i3 is produced in the USA (Moses Lake, WA), so it’s at least a little bit american.

Would be very interesting to have efficiency at different speeds analyzed for the current EV crop. As this would allow people to pick the vehicle that suits them best for the driving they do.

I want a real side by side test of these 2 cars on a 5% grade where both cars enter the bottom of the hill exactly at the start of REx mode.

I did the test on my Volt and reported the results in a detailed article found here:

The Volt very easily held a constant 65 MPH on the 5% grade.

Of course there would be no point in doing the comparison since the Volt would have won hands down.

but alas I know these are 2 different cars and that the design philosophies are just different.

The Volt is still the best bang for the buck out there….but then I guess I’m prejudice since I own a Volt.


Don’t worry. With the same speed that BMW unleashed the “i3 Blog Squad” in an attempt to bury the nasty little fact that this thing won’t go up a hill, BMW will unveil its new, improved Fuel Cell i3 ReX.

I’m quite certain it will be as well thought out as the current CARBMobile and looky here, Nine Points! Of course, the lease rate will probably be as much as a HondaJet.

Mentioning the i3 in the same sentence with the Chevy Volt is about as silly as comparing the i3 to a Tesla. But if you repeat something over and over and over again people start to believe it, right?

I recently took a trip in our Volt touring Mt. St. Helens and to the Sunrise entrance of Mt. Rainier at 6400 feet (not high for Coloradans but don’t forget starting elevation:). I have to say that I appreciate the ability to not even have to think about if the Volt will handle the range or grade.

Tom is putting on 33k a year in New Jersey. I am putting on 11k a year out west. We’ll both be over 90% EV, and I think we both chose the right tool for the job. For subsequent generations of plug ins, I hope the variety keeps increasing. One size does not fit all.

No. I think you are correct. 11k is a lot of money.

The difference grows to $15k when you consider Volts are selling on the average $4k under MSRP.

Yup. And soon they will be liquidating the 2014’s. I bet discounts on those will be $8K this fall.

They don’t “liquidate” Volts. Countless claims usually back into the same 4, or 5, off. Some conflate their GM credit card points into the mix, but this includes “loyalty” and “consumer cash”. BTW, the i3 is currently 2-3k off depending upon region. This is all discussed on the place we know and trust, called the internet.

Tom fails to mention the cost of his i3’s wrap- a non-stock color option. i3 owners and blogsites always seem to chince on the MSRP. Go to and read the prices on the i3s with ReX. I’m finding $55,000+ for the Terra Cool package with the goodies. The price quoted here is more a mid-level BEV i3. So go nuts for all those dollars. Volt has a form-factor of a racey, swoopy fastback, while i3 has the form factor of a minivan. So go nuts driving all performancey* – haha…( not a word, but my word for BMW drivers’ habit of making every right hand turn or freeway onramp the Nurburgring or Indianapolis 500 ). So a guy zipping around squealing the itty-bitty motorcycle tires ( price those proprietary replacements = boy! ) in a car that looks like an ugly minivan…and, like I say -…knock yourself out, fella! I prefer the Volt form factor, even if it does ride a bit soft…it makes Prius look like a shopping cart in the driving dynamics category. Volt does have a plastic interior and needs improvement, but is near replacement whilst i3 is a brand-new model. Deals on Volt are numerous… Read more »

I don’t know about the Volt being a sleek design. Parked next to my Focus EV at the car show, the Volt looks 90’s boxy and old fashioned. At least the i3 has a futuristic look to it. Unmistakable. Whereas the Volt kind of looks like other Chevy’s from the front. The point is on EV only, the i3 blows away the Volt. Highest efficiency of the US production cars. So you want performance too? Car and Driver just got a 6.5 second 0-60 time in their i3 test. Quickest in its class. So the Volt as a bigger ICE engine and biggest gas tank? Not exactly something to be bragging about being ground breaking technology. The i3 is record breaking. Give credit where its due.


I think of the last 30 trips I have made from/to my house. They weren’t earth-shattering adventures, but they did accomplish many tasks and do some meaningful work. A car as a tool, not a toy. We can use our main transportation car as a toy – you know – carve corners as if we were imagining being an F1 driver, punching the accelerator from the stoplight – sure, we’re breaking laws in doing so, but as long as we don’t get caught – it adds to the fun, right? Well – we also know if we get speeding tickets, oiur insurance will go up and perhaps even lose our license, so our logical side knows the track is the place for shenanigans like these. It’s much better to have fun when not putting others’ safety at risk. Even so, that fun comes at a price of tires, and wear-and-tear on pricey car parts far above the commute or trip to the supermarket. With an ICE car, you can do a burnout and carve around some curves on a mountain road and your friskiness won’t mean you don’t make it to the next destination. With gas, filling stations aplenty line… Read more »

You don’t seem to be understanding that getting relatively good economy and having fun do not have to be two exclusive things! I’m sure there are plenty of people out here that will take good acceleration if it is available in one of the most efficient vehicles in the US. For one, it can be a safety factor in getting you out of a jam, and secondly, many of us have fun achieving max acceleration at times in our current EVs. The point is, in my LEAF and Focus, I drive fairly spirited around town. I still average about 90mpge. The same exact driving in my ICE Mini Cooper S, rental 2014 Altima, or 2013 328i yielded 16-17mpg! So comparing 16mpg of the ICE to 90mpge driving the same spirited way is still about 5 times more efficient in the EV. Don’t you find that a big advantage regardless of how you like to drive?

Also, I just sat in the rear of an i3 yesterday. The coach doors are no problem when it comes to ingress/egress. And have you actually priced out the tire of those special Ecopia tires? They are probably among the cheapest of the current line of BMW model tires.

As I said. As a techie fan and perhaps one in wonderment mode of something “new”, you aren’t the best judge of the usefulness of these rear doors. Parents are. And, as I’ve said – folks for whom the new car rush has faded. Many pickup trucks have had these opposing doors without handles on the outside that have to be operated in a specific order. What happens is – you, the driver, have to instruct your passengers how to work the doors. This is fine in the beginning…But soon – human nature shows we tire of reminding folks how to use a car door. The end result if you forget to tell people, is that they learn by trial and error. LOL! This means fiddling and banging the door and wondering why it doesn’t shut, then banging it harder and then becoming frustrated whilst you then sometimes have to get out – travel to their side and close the door for them!!!! Now to you, at the auto show or showroom…Or if you’re like Tom and use the rear cargo area – but mainly use the front two seats in daily use…You may be OK with it. But if… Read more »


Good comparison Tom, it seems like you did this fairly and I enjoyed reading. I have some questions about this part in the Efficiency section..

>>”We drove with the climate controls set to 72 degrees and the windows closed.”

For the Volt, do you recall what climate mode was used? Regardless of the temperature I have it set at, it seems there is a big difference in the energy usage % for hvac. This would make a difference in the efficiency tests. Where I live the climate is pretty mild. Most of the time I leave it in Eco mode, but I am able to use ‘Fan Only’ mode almost as much, and rarely have to put it on ‘Comfort’. Does the i3 have similar modes?

I agree that the VOLT could use a higher power charger, and 6.6 Kw charger makes sense, but they could also add the Spark EV’s DCQC option as well.

Meh. Most of the charging is overnight and does fine with 3.3KW. And you always have gasoline when you need it. If you want to drive more on electricity then consider going pure electric.

That Volt is looking good

What I’d really like is a Volt w/a battery the size of the i3.

Charging capabilities too.

+10! That’s totally where it’s at. My commute requires exactly those specs to get close to 90% electric. I’m getting a bad feeling though that this is not in the cards for the gen 2 Volt. Hope I’m wrong.

I found this to be a very useful article, since I am a 2012 Volt owner considering a BMW i3 in the not-too-distant-future. Having driven an i3 twice I do like the performance feel over that of the Volt. However, I also like the Volt’s quietness. What a quandry!

woudn’t recommend a volt to an i3, just get the grandaddy of them all, the tesla

Nice word choice, Tom. To each, his own, as far as what “frequent”, “long” trips mean.

You guys need to get back together, this winter, using that same 72 degree setting. I believe that’ll be the “fat lady” at the opera.


i3 has much more room. The volt makes you feel like a sardine.

I don’t like either cars….lol


i3 is CFRP (Carbon Fiber Reinforced Plastic).

So, the conclusion is that if you like the i3, you will buy the i3 (Tom). If you like the Volt, you will buy the Volt (Dave)


Geez, I could haven’t told them that.

Tom’s point is valid. Both are good cars and designed for slightly two end of the same EREV stick.

BTW, I hope they repeat this in the winter when the extreme heat is needed.

Also, repeat this with Volt 2.0.

Guys, don’t be fooled by this so-called comparison. I have read of three different occasions where the BMW i3 Rex have lost a significant amount of power on the highway because the generator could not maintain the state of charge of the battery (once in the UK and twice in the US). As far as I know, there has never been such a case with the Volt. The Volt is a better car and much more affordable. It is very unsafe for the BMW i3 Rex to cut your speed in half in the middle of the highway without warning. This is a major accident waiting to happen. If you are driving on the freeway and your BMW I3 Rex suddenly looses power and you can’t get it to go any faster than half the posted highway speed don’t be surprised if you are pulled over by a highway patrol officer. It is a safty hazard.

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

But it is narrower. That probably helps for aerodynamics but perhaps they should have made it a little bit wider so they could fit a 5th passenger in there . . . and more more batteries.

Both cars are great though and it seems which one is better for you depends on your particular driving needs.

Tom, at the beginning you said that the Rex was misunderstood and that it wasn’t a “limp home” or emergency backup. But then at the end you recommended against using it for long trips, which seems to imply the opposite. Was that recommendation only based on the size of the gas tank? If it had a ten gallon gas tank and you weren’t driving up the Rockies, would you recommend it for long trips? Why or why not?

That is a very good question John. “If it had a ten gallon gas tank and you weren’t driving up the Rockies, would you recommend it for long trips? Why or why not?” I will be checking to see if Tom Moloughney answers it.

Elroy says he prefers the looks of the Ford Focus Electric over Volt. I grant you aesthetics are TOTALLY subjective. I differ from you in that while a couple details of Volt I would change – I do really enjoy it’s appearance and consider it very sporty looking indeed. Myself, I don’t mind the appearance of the FFE and Ford Fusion Energi, I just have to look at the wheels and tiny details to determine them from their ICE counterparts. There is no ICE Volt counterpart, and I very much like that it’s a stand-alone vehicle. Elroy says i3 is quicker and thusly may be safer in some situations. I own a 2nd gen. Prius and it’s slower than my Volt. Never in 7 years with the Toyota and 3 years with my Volt have I ever been in a situation where either one was so slow as to put me in a dangerous situation. If you read BOTH VERSIONS of the above comparison – one on and this ( Tom’s ) version – one guy chose Volt the other i3. In the Volt owner’s article he states i3 feels quicker because of it’s allows in more road noise,… Read more »

To me, the i3 is much more “utilitarian” in looks and overall ability. I still wish today that GM had tried to put the Equinox platform into a Volt style setup. Or maybe the smaller SUV like the little Buick they make into this class. I think it would get a lot more attention and probably even more buyers that way. While the smaller Cruze platform seems like a good choice on paper, it’s ultimately very limited in appeal to today’s buyers.

Thanks for a great read! Im going electric here in sweden and have boiled it down to two options, curios about your advice. Family with two forward facing kids (4 and 6), mainly daytrips and vacation driving. Single car, commute with bus. Drives about 9000 miles/year.
1 – Ampera 2012, 86000 miles, 14500 usd
2 -i3 rex 2015, 50000 miles, 22000 usd
Very hard to guesstimate these vehicles future depreciation since very few bmw’s on market with higher miles and very few amperas/volts overall.