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BMW i3
- Thread starter gregincal
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- Electric Vehicles
I'm sure I'd get bored but out of curiosity, a look at the numbers...
starting wad: $1,000,000,000
days to live: 100 years * 365.25 = 36,525
available outflow per day: $27,378.51
Assume expensive 3 meals a day: $300
Assume $200 hotel room a day: $200
Assume a ritzy new set of clothes every day: $5,000
$21,878 extra to spend on non-essentials daily
I could keep myself from being bored for at least a few years like that.
Brewster's Millions comes to mind.
Brewster's Millions (1985) - IMDb
Actually, I disagree. Sometimes having a viable alternative opens up the market, and both suppliers grow more as a result. Now, I agree that the i3 isn't much of an alternative, but I'm sure there are some die-hard bimmer fans that will buy it, and it looks like a perfectly viable car in European cities, so maybe it will be a success, and get more people to actually consider Tesla (and other) electric vehicles. So he may be wrong about his own car, but I think his logic is correct.
Agree. Having alternatives is healthy. There are many on this forum who own other EV's and Hybrids and their feedback is often very insightful and much appreciated. I'm sure once the i3 is available there will be forum members who will lease an i3 while they wait for Gen3. Getting their feedback will be very interesting. Even though the i3 is compromised in many ways the more attention EV's get is a good thing.
surfingslovak
Member
Yes, we have seen this effect with other EVs as well, and I would personally know a number of LEAF owners who have purchased a Model S or a even a Roadster. That said, the comparisons between the i3 and the Model S are both ridiculous and a bit unfair. It's similar to the face-off between the Volt and the LEAF two years ago. They were a different vehicle type (BEV vs EREV) with their own strengths and weaknesses, yet the press ended up pitting them against each other because there were so few other choices on the market at the time. Discounting the Cadillac ELR, there is no other EV in the premium segment as of this writing, and the comparisons drawn between the Model S and the i3 go sometimes a bit too far. I too would have hoped for a stronger BEV variant, and considering the weight and cost penalty of the REx, it looks like BMW could have made a 30 or 32 kWh BEV with a comparable weight and price. That said, it looks like the i3 is getting plenty of attention and could sell well. I'm hopeful that this will be the case, since a rising tide lifts all boats.
Indeed. I have learned quite a bit from Roadster and MINI-E owners, which led me to the ActiveE program later. The EV community has certainly benefited from both the LEAF and the Volt. These owners have collected invaluable real-world driving experience and most of them will continue to drive electric. Same goes for the lesser known EVs and compliance cars.
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smorgasbord
Active Member
From what I can tell, the 650cc scooter engine that BMW is using as a range extender will output about 35hp, because they're not going to let it run at 7500rpm. (http://insideevs.com/bmw-i3-range-extender-is-nearly-flat/). As others have pointed out, that's not enough HP to keep a 3000+lb car (range extender adds 350lbs) moving at decent acceleration nor speed. So, that means getting the range extender to come on well before the battery is depleted, since you don't want to drive solely on the electricity it's producing in real time.
Now, some have said that CARB rules prohibit the engine from coming on until the battery is almost depleted, but the Volt has a Mountain Mode that lets the engine come on at only 50% depletion. So, presumably BMW could do that as well. Of course, you'd have to live with the engine running at how every many thousand RPM even if you're standing still at a stop light (like the Volt and Karma do, or at least did). The Karma didn't qualify for HOV stickers in CA, btw. To top it off, the range extender adds almost 3/4 second to the car's 0-60 time and reduces the all electric range noticeably.
I'm having a hard time imagining the range extender being practical. Either it doesn't come on until the battery is depleted and then you've got a 1.5 ton car running on a 35 hp powerplant, or it comes on after 40 miles and runs all the time no matter what speed you're driving at. I guess it's a limp home on the side streets emergency mode, but for almost $4K and 350lbs, I'd rather have another 15kWh or so of battery - wouldn't you?
The BMW i3 really competes with the Tesla-powered Toyota Rav4EV. The BMW is probably nicer on the inside, but the Rav4 has more Tesla battery power.
Now, some have said that CARB rules prohibit the engine from coming on until the battery is almost depleted, but the Volt has a Mountain Mode that lets the engine come on at only 50% depletion. So, presumably BMW could do that as well. Of course, you'd have to live with the engine running at how every many thousand RPM even if you're standing still at a stop light (like the Volt and Karma do, or at least did). The Karma didn't qualify for HOV stickers in CA, btw. To top it off, the range extender adds almost 3/4 second to the car's 0-60 time and reduces the all electric range noticeably.
I'm having a hard time imagining the range extender being practical. Either it doesn't come on until the battery is depleted and then you've got a 1.5 ton car running on a 35 hp powerplant, or it comes on after 40 miles and runs all the time no matter what speed you're driving at. I guess it's a limp home on the side streets emergency mode, but for almost $4K and 350lbs, I'd rather have another 15kWh or so of battery - wouldn't you?
The BMW i3 really competes with the Tesla-powered Toyota Rav4EV. The BMW is probably nicer on the inside, but the Rav4 has more Tesla battery power.
EVNow
Well-Known Member
25 kW is actually quite good. If you were to empty i3 (or Leaf) battery in an hour, you would have used about 20 kW on average and probably driven at 70 mph. Apparently REx comes on at 18% SOC. That mean some 3 kWh of reserve is available on top of the 25 kW. That is good enough for non-limp mode travel on non-mountainous terrain.
You think a small four-seater competes with an SUV? That doesn't make much sense.
I still think the i3 mostly competes with the Volt. The closest pure EV is probably the Leaf, but the i3 is different enough to not really be a close competitor.
smorgasbord
Active Member
I think when you look at interior volume, the i3 won't seem so small.
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I guess I'm biased by thinking about a 3000 pound car is being pulled by a scooter motor that's been derated to less than half it's normal output. I had a bike with a 40hp motor, and that was just fine, but this car weighs 7.5 times as much as my old bike! I just can't see that working, regardless of the steady-state numbers say. Can you help me understand?
i3:
- Seats 4 people
- 260 liters of cargo space with rear seats up
- 1100 liters of cargo space with rear seats down
Chevy Volt:
- Seats 4 people
- 310 liters of cargo space with rear seats up
- 1005 liters of cargo space with rear seats down
Nissan Leaf:
- Seats 5 people
- 370 liters of cargo space with rear seats up
- 720 liters of cargo space with rear seats folded down
RAV4 EV:
- Seats 5 people
- 547 liters of cargo space with rear seats up
- 1746 liters of cargo space with rear seats down
The RAV4 EV blows both the i3 and the Leaf out of the water. And the Leaf is significantly better than the i3 with rear seats up. The Volt however is similar in size.
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The reason that the i3 will not perform like a 35 hp car is that *full* electric power will be available for a few typical accelerations using the "depleted" battery just like a normal hybrid does. This is called "charge sustaining mode."
The Volt does the same thing, giving 111 kW performance with a 55 kW generator. However 55 kW is much more livable when climbing mountain passes than the i3's 25 kW will be.
GSP
Should e pointed out to non Californians that the first year Volt did not qualify for CARB stickers. GM pretty much lobbied themselves in. At least Carb gave them a green sticker (as opposed to the white one for pure EVs) so CARB can drop them later on like the did with the Prius and their yellow stickers.
And I'm with Smorg on this "free energy" bamboozling. A tiny motor can not drive a big car in a normal fashion. Running it's output through a battery to an electric motor is not magic. It's actually a bit less efficient than direct drive since all power conversion has a a little loss.
However, as long as the engine provides more than the average power needed by the car than the battery takes care of providing the needed power during the peaks and absorbs energy during the troughs. If you're driving 60 mph, than that works out to 25kWh/60 miles, or about 400wh/mile, which is plenty of energy even accounting for charging losses. The car obviously isn't a drive anywhere car like the volt, but generally shouldn't have any trouble sustaining normal driving while using the ICE under most circumstances. Since the energy produced by the engine is constant per time rather than mile slower average driving is better, and faster worse.
smorgasbord
Active Member
OK, so another way of looking at it is that instead of sitting at 900 rpm idling or 1500 rpm doing 10 mph, the engine will be doing 3500 rpm (or whatever) all the time and thus be putting electrons into the battery for use on subsequent accelerations, etc. Could work, if BMW has figured out the NVH issues. I wonder what the MPG is when the battery is just about empty.
Looking at the Volt and Karma, which are the other 2 range extending vehicles I know of, the difference is that both of those actually use the engine to generate more power during normal driving, while the i3 is all battery electric. The Volt has an undersized electric motor, so the gas engine kicks on when you need the oomph, and the Karma's battery doesn't output enough on demand, so the gas engine kicks in to supply more juice. BMW went with a full-sized (for lack of a better term) battery/motor, so all the gas engine does is charge to the battery. I guess BMW decided not to do the Karma thing and route juice from the gas engine directly to the motor because then it would qualify for the HOV stickers, like the Karma.
I expect that the reaction the the BMW i3 is not what BMW expected. Some jumped on "it's a BMW EV" and thought it was instant competition for the Model S. Others looked at the outside and poo-pooed it right off the bat. Unlike other manufacturers, BMW actually did a bunch of EV field testing with real people via the Mini-E and Active-E, so I figure they've got how the i3 performs pretty well dialed in. I also think the i3 will look better in person than in the photos/videos, and especially the interior will feel much more open - like a Model S, not a Rav4 or Volt (or Karma).
gnelson
Member
I have to disagree with smorgasbord. I own a Volt and understand its operation. The ICE is only operational in the Volt when the battery is depleted. If you use Mountain Mode the ICE will start sooner. Once the ICE is operational it can also assist in propulsion, but it is mostly used for electricity generation. I have plenty of oomph in the Volt without the ICE, and it is never utilized in my Volt in Houston unless the battery is depleted.
gnelson
Member
The reason that the Volt has enough oomph is the motor generator will supplement the 149 hp electric motor giving more than 200 hp of electric propulsion.
See the article that explains the 4 modes:
http://www.designnews.com/document....84,industry_auto,aid_229545&dfpLayout=article
People should think of the Volt as and EREV (extended range electric vehicle) although is is technically a hybrid. The problem with the hybrid label is people totally misunderstand how the volt functions!
See the article that explains the 4 modes:
http://www.designnews.com/document....84,industry_auto,aid_229545&dfpLayout=article
People should think of the Volt as and EREV (extended range electric vehicle) although is is technically a hybrid. The problem with the hybrid label is people totally misunderstand how the volt functions!
smorgasbord
Active Member
gnelson
Member
It is easy to get confused because the Volt has 4 different operating modes, and that can be confusing. Most of the time it is only being propelled by electricity. Another issue contributing to the confusion is people are dogmatic about referring to the Volt as a hybrid. As I have stated it is technically a hybrid, but it is actually and EREV. Others seem to want to diminish its operation to make the i3 seem to be a better alternative. I would never consider buying the i3 vs a Tesla Model S or vs a Volt. I look at the Volt as being a very good alternative for a second car with the Model S being my primary car. If I had unlimited cash, I would have 2 Model S' and no Volt. The Volt is priced competitively with the i3 and is so much more utilitarian not too mention being much more visually appealing.
EVNow
Well-Known Member
I had the same issue.
In general when you drive, you need more power only when accelerating or going up a hill. The battery supplies these bursts of power.
I was worried about going up the various hills around Seattle area at a decent clip. For eg. in Leaf, I need about 40 kW to go up a hill (12 to 15% gradient) at 40 mph or so. We can get that 40 kW in i3 by using the 25kW from the genset and 15kW from the battery reserve. Infact we can go up this way for some 7 miles. Similarly, you can calculate how far you can go on a gentle gradient on freeway @ 70 mph etc. So, what I figure is 25kW is adequate for "normal" driving everywhere - except probably across a mountain pass.
Apparently when BMW guys were asked whether REx implies limp mode - they were surprised by the question and said "ofcourse, not", paraphrasing. So, my guess is they already figured out what is needed for normal driving and came up with the 25kW as the needed power.
Still, my interest in i3 is mainly for this REx - since it is too expensive as a BEV compared to Leaf without much extra to offer (4x my Leaf lease). So, I'll be doing some test drives on REx before signing on the dotted lines.
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