Thursday, May 8, 2014

BMW i3 BEV vs REx: Your Purchase Matters



On REx models the i3's range extender sits next to the electric motor above the rear axle.

Many people considering a BMW i3 are a bit torn between the full electric version (BEV), and the range extended version (REx). What they may not know is their decision will indeed help BMW decide what electric range their future EV offerings have.

Now that the EPA range rating for the BEV i3 has been announced at 81 miles per charge customers can finally decide if they BEV i3’s range will suit their needs. If it doesn’t and they still want an i3, their only choice is to fork over the extra $3,850, and get the range extender. There are electric vehicle enthusiasts that consider this unacceptable because they don’t ever want to put gasoline in their electric vehicle, it just seems wrong to them. Others don’t mind, since they will be driving on electric the vast majority of time and using a little gas is OK with them.

Basically there are four main groups of perspective i3 purchasers:

1)      They are interested in the i3 but the 81 mile EPA rating is just too low for them and the range extender is out of the question. They walk away from the car and consider their other electric vehicle offerings.

2)      The 81 mile range works for them. They get the BEV i3 and understand its limitations.

3)      They really wanted the BEV i3 but the range rating was too low for their comfort so they reluctantly ordered the i3 REx. (I fit in this box)

4)      They really liked the idea of the range extender from the start and wouldn’t have bought an i3 without it. The ability to drive primarily on electric but have the range extender there for the few times they need more range is perfect for them. Not ever worrying about getting stuck on the road because they ran out of charge or a public charger was broken or blocked is paramount for these people.

Of course there are other factors, like local incentives and especially HOV access in California, but these are generally the four boxes the typical potential i3 customer will fit in. It will be interesting what the percentage of BEV buyers to REx buyers are, and don’t think BMW isn’t watching that very closely. I have personally spoken to BMW mangers that have said the breakdown of BEV to REx sales will give BMW a clear indication of what range people are comfortable with. If BEV sales dominate, BMW will take that as verification that the range they gave the i3 was right for this vehicle and perhaps consider future low-range EV's. Conversely if the majority of i3s sold are range extended versions, or if sales in general don’t meet expectations they have a clear message: The potential customers didn’t believe 81 miles per charge was enough, especially for premium brand EV and they are more likely to make the next EV they offer have a longer range. In other words, your purchase is your vote. Buying a BEV i3 is telling BMW that 81 miles is fine, and buying a REx i3 is telling them it’s not.

Hopefully BMW will break out the sales of the BEV i3s and the REx i3s in their monthly sales reporting instead of just including them in one group. That may just help to give us a better idea of what to expect next from the i brand.

25 comments:

  1. BMW's plan isn't completely water tight though. Later I might want to send a different message than the one made by my wallet.

    I'm buying into the idea of security upfront as the REx mitigates the transition to a fully electric car. If I realize the extended range doesn't get used much I'd want to send the message that I could have used a BEV all along.

    I'm guess I'm just suggesting that in terms of how BMW shapes their future product offering I'd expect them to consider sales just a portion of a rapidly evolving market.

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    1. Yes, it's definitely just one factor they will consider. I didn't mean to imply it is the only thing they will consider. For what it's worth, I do believe BMW will come out with longer range EV, regardless of how the i3 sells, but they are indeed watching how BEV sales compare to REx sales. If REx sales overwhelm BEV sales That is a clear message to BMW that most customers didn't believe they could live with a 60 to 90 mile range.

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  2. I wonder how the decision to buy the REx version will be influenced by prior ownership of an EV. I have had a ford focus electric for over a year now. Anxiety about how this experiment with a pure EV would work for me influenced me to get a short 2-year lease on the Ford Focus Electric. However, having had the car for over a year, I am confident that a 81 mile range is fine for me (we do have a second car for longer trips if needed). I am looking forward to the BEV i3 and do not think I need to spend extra for the REx. However, if I had the option of a slightly longer range with a bigger battery I would probably take it. It would be shame if my current choice for the non REx version serves to dissuade BMW from providing such a model in the future.

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    1. I would have preferred an optional larger battery to a REx as well. Maybe, BMW will make it a third option in the future, for the people in categories 1, 2 and 3.

      To be quite honest, BMW's "marketing" evaluation of the model sales (BEV vs. REx) won't mean squat in a couple of years. Once Nissan has a 150 mile LEAF and Tesla has a 200 mile Gen III, very few people are going to want an 80 mile BEV or an extremely limited REx.

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  3. I've been driving electric for 5 years now. The first car I had was the MINI-E and it had an average range of about 105 miles per charge in fair temperatures. I now have the ActiveE and that has about a 94 mile range in the same conditions. The i3 should have about an 80 mile range. It's just not enough for me, as I drive more than the average person. In the winter, the i3 will have about a 55 to 60 mile range (I know from the people in Europe that had one through this past winter there) and that just isn't enough for me. I could barely make it with the ActiveE and losing 10 more miles of range would make it just too inconvenient to rely on for my every day driving needs. I love the i3, but reluctantly need the range extender. Not for range anxiety, but because the range simply can't accommodate my needs.

    BMW's has consistently reduced the range of it's EV's and that is indeed puzzling to me:

    MINI-E: 90 to 110 MPC
    ActiveE: 80 to 95 MPC
    i3: 70 to 90 MPC

    Of course you can get more or less than that will efficient driving, But with each new EV BMW has reduced the range nearly 10%. It's puzzling.

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  4. I'm solidly in the #4 camp, as I believe the REx version to be the more environmentally friendly vehicle for most people, as it eliminates the need not only for a second gas guzzling vehicle completely, but can be used mostly electric for trips just beyond the range of a BEV. A bunch of folks on Tom's forum site compiled a list of good reasons to purchase a REx:

    1. It is incredibly inexpensive. You cannot find a liquid cooled, highly efficient, staggeringly low emission 34 hp gen-set anywhere for $3,850, much less one that imposes no volume penalty, and integrates seamlessly with the i3's electrical system.

    2. It imposes a negligible weight penalty, slowing the zero to sixty time by only 0.8 seconds (still quicker than any other EV except the Teslas), and increasing the fuel consumption to carry the additional weight by only 4.65% (seehttp://www.bmw.com/com/en/newvehicles/i/i3/2013/showroom/technical_data.html#m=i3_range_extender) or roughly $129 (assuming $0.11/kWh) over the course of 100,000 miles

    3. It eliminates the cost to rent or own and maintain a gasoline fueled vehicle for trips beyond a BEVs electric range.

    4. It eliminates both the embedded and produced pollution caused by renting or owning a gasoline fueled vehicle for trips beyond a BEVs electric range.

    5. It allows for a greater ratio of EV to gasoline powered driving for any given size battery bank:
    - For EV only trips, it allows for full use of the battery's capacity, as the driver need not hold any EV range in reserve
    - For trips beyond the range of a BEV, it allows for not only EV use, but use of the the battery pack's full capacity. Consider a trip of 110 miles, only 100 of which could be reached by a BEV in its most economical mode. The BEV would stay in the garage, and the gasoline powered vehicle would travel the full 110 miles on gasoline only. A REx would be able to travel approximately 90 miles on electrical power, and need to travel only 20 miles using gasoline.

    6. A BEV is limited to travel only between charging opportunities, making most trips outside of a roughly 30 mile radius inconvenient (3.5 hour wait to charge), and many trips impossible (no realistic charging opportunity). A REx can travel pretty much from any point on a map to any other point on the map conveniently with only a few minute stop for fuel every hour.

    7. The REx offers the flexibility to change plans as situations change. An unexpected errand that would be impossible for a BEV to include in its planned range for the day would not even be a second thought for a REx

    8. Certified morons like myself occasionally forget to plug the car in at night. A REx would get me to work the next day with no issues, whereas doing the same with a BEV would cost me over $150 in cab fare.

    9. The battery range degrades tremendously as temperature drops - not so with the REx.

    10. The battery capacity degrades with time and use - not so with the REx. A trip that you might be able to make on a brand new battery may be impossible 8 years and 100,000 miles from now when the battery will have degraded to as little as 70% of original capacity (BMW's warranty figure).

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    1. This comment has been removed by the author.

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    2. "The battery range degrades tremendously as temperature drops - not so with the REx"
      Is that because the REx helps warm the battery or is it that power from the REx compensates for loss of battery power so its deficit is not felt by the driver?

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    3. I think the range will take a hit in winter but the Rex will ensure the SOC does not get low enough for the performance to degrade much. But we do not know for sure yet...

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    4. There is no reason to expect any acceleration performance decrease due to cold weather. The car should be capable of tapping the full 170 hp / 184 ft-lb throughout a broad temperature range regardless of where the electricity is coming from. The point I was making is that the pool of energy stored in a battery decreases significantly with temperature, whereas the pool of energy stored in a gas tank does not.

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  5. My first thought was why does BMW have to figure it out themselves, isn’t there already a good deal of evidence that some buyers are worried by a 80 mile electric range? I suppose the reality is that how much a buyer would spend for more range varies by market segment. BMW has to gauge it for their own product. Leaf buyers aren’t going to be as willing to spend $10K for an additional 15kWh as Tesla buyers, for instance.

    I’m considering an electric car right now and have to make that same judgment myself. Just about anything electric can handle my normal commute, as a matter of fact I do it on an electric bike when the weather is nice. I still like the idea of the Rex for those rare times I’m venturing outside my home range.

    I’m exasperated by people that insist that they need a car with 500 miles of range and a 5 minute refuel to accommodate their once a year road trip; no compromises. But I do get nervous considering being restricted to an 80 mile range with a multi hour recharge, even though that might only be an issue a few times a year. The REx seems like a worthwhile backup option giving you peace of mind if you’re going to be pushing the limit of your range and the ability to way exceed it if necessary.

    The inconvenience of the small tank and the possible limitation on sustained high speed actually makes it feel more like a real electric car rather than just a plug in hybrid, even if the difference is just one of scale and technicalities. I still wish US got the “Hold state of charge” option, however.

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  6. Thinking about the range of the Rex, everybody agrees will be shorter than the Bev, but is it not because the battery will not deplete the last 6.5% while on the Bev it will? All explanations are focused on the extra weight of the Rex, no mention of the above SOC difference. I'm estimating 71 miles range and 40 mpg combined for the Rex, for an ideal total range of 140 miles. Plenty for a city car, even for a suburb car...
    Also, the noise will be higher with speed in US as it tries to keep the SOC at 6.5% by changing the Rex RPM accordingly... so around town it should not sound like a lawnmower unless you are seriously speeding...

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    1. Alex, the range will be effected by the extra 265lbs the REx weighs, but the main culprit is as you mention, the fact that the Rex turns on at about 6%.

      Even if they weighed the same, the REx would have about 6% less all electric range. I expect your 140 mile estimate to be about right, but don't forget, you can simply fill up with gas if you need to go further and as long as you keep it under about 74mph, you can drive as long as you need to.

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    2. Indeed one could do that - a small gasoline canister that fits in the frunk could fit about 2 gallons (based on visual estimates of the frunk size).

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    3. Alex,

      A comparison of kWh per 100 km for the two vehicles on BMW's spec site (http://www.bmw.com/com/en/newvehicles/i/i3/2013/showroom/technical_data.html) shows that the extra weight of the REx system imposes a 4.65% consumption penalty. I agree with your 71 mile electric range estimate, since the 6% REx operation reserve added to the 4.65% consumption increase would add up to reduce initial electric range to 89.4% of the 81 mile EPA range, or 72 miles. What we all might be missing (to include the EPA, whose testing protocols may not be sophisticated enough to catch it) is that after gasoline depletion, there is still ~6% useable battery capacity remaining, which should be good for another 5 miles, bringing the total REx EV range up to 77 miles.

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  7. One thing I cant figure. when they gave up the heatpump on the rex model, hy didnt they use hot coolant from the rex to heat the cabin? you would only get it when the rex was running or at least warm, but at least the car would have longer range in rex mode, as it is some of your fuel goes to generate electricity to make heat for the cabin, while waste rex heat is dumped into the atmosphere to cool the rex.

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    1. None of us work for BMW so can only speculate that the limited scenario when such gains would exist would not justify the added complexity as the space under the dash seems to be very crowded (bad on the schematics online).

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  8. I'd put myself into a 5th category: category 4, but only if I could buy a European spec range extender. At this point I'm probably going to hold onto my gasoline car until BMW comes to their senses and offers a non-crippled REx in non-CARB states, or the 150-mile-range Leaf becomes available, or the Tesla formerly known as Model E becomes available.

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  9. I've been all over categories 2 and 3 for most of the wait... However, I may end up as category 1 (per your prediction as well.). http://pascual.co/ActiveE/2014/05/if-tom-is-correct-about-bmw-i-guess-theyll-just-lose-me-as-a-customer/

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  10. I would have fit in #3... I know I would have had to get the i3 REx version as I often drive 100-150 miles in a day with no way to easily recharge.

    I really like the i3 but in Georgia it would have cost me an additional $5,000 tax credit that a BEV qualifies for. I also do not like the fact that you cannot engage the Rex early when needed for highway speeds like you can in Europe. North GA does have some steep long grade hills. I understand the reason for the REx limitation based on the ZEV credits, but I disagree with it in that while it helps BMW sell more ICE cars in California, it hurts the ownership experience in my opinion.

    I wound up with an 85Kwhr Tesla Model S and after driving it for a few months it was the right choice for me. I am in sales and support for an area roughly 100 miles in diameter. Unexpected trips are common but usually less than a 50 mile detour. I have been charging the Model S to about 200 miles of range and have got down to 50 miles several times doing my daily driving. I now realize that I would have had to use the Rex more often than I originally though I would especially in cold weather. I am not sure how well the REx would hold up to that much usage over time. The "Not for Daily Use" statement by BMW executives would have always been in the back of my mind. Likewise, I am not sure that 100% (or 90-95%) cycling of the battery almost daily would be good for the pack.

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    1. Horses for courses. Sounds like you chose wisely, based on your everyday needs. Good hearing from you again. One slight correction though, the REx would only need to cycle approximately 82% of full charge assuming daily depletion of all available battery capacity prior to REx engagement. It holds 13% of total capacity in reserve for all operations, and an additional 6% of useable capacity in reserve for REx operation.

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  11. I'm not buying it, the REx, and the REx versus non-REx determining the range of future i cars. BMW can't be that stupid, when cars with greater range enter the market BMW can't say "our data shows that 81 miles is enough". They will respond or loose customers, when the Tesla Gen3 premieres Tesla would destroy BMW if they stuck to low range numbers. Picking between the REx and non-REx i3s has to be a choice between gas and electric, look at BMW-i and BMW's other plug-in offerings, they're all plug-in hybrids, except one, the non-REx equipped i3. If the sell more REx i3s they could drop the electric only i3s sighting demand.

    ,CDspeed

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    1. Picking between the REx and non-REx i3 is more of a choice between the most efficient and the 5th most efficient EV available for sale. The next realistic step up in range (the 60 kWh Tesla Model S) imposes more than a 30% increase in consumption per mile. There is a market for vehicles built to help reduce our impact on the planet, and I'll tip my hat to BMW for giving us the two best vehicles in their respective classes to help us do so.

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  12. Anybody have a pic of the BMW i3 REx ICE and its generator? An extensive search of the web only reveals engines for BMW scooters and bikes that BMW says it has based the ICE used in the car.

    Its not hard to stick a camera under the car. Does BMW have a squad whose job it is to scrub pics of the engine from the web??

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    1. Very easy to find: http://www.etk.cc/bmw/EN/search/selectCar/I01/MCV/BMW+i3+Rex/USA/11/

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