BMW joins the lithium mild hybrid game
The BMW 7 Series ActiveHybridBMW will debut the new 7 Series ActiveHybrid at the Paris Auto Show next week, a vehicle that was developed out of a joint venture with Mercedes Benz and the S400 hybrid. However, while much of the hybrid technology is the same, the gasoline engines and gearboxes are quite different according to Edmunds.
Yes, this is another luxury hybrid that most of us will never consider purchasing, but it is also another example of the growing interest in lithium-powered mild hybrid powertrains. And, soon, such lithium powertrains will make their way into much cheaper hybrid vehicles. Is that not progress?
Labels: BMW Series 7 ActiveHybrid, Hybrid Vehicles, mercedes s400 hybrid
posted by Dahcredyns at
8:35 AM
17 Comments:
This is just about global warming emissions. They'll do as little as possible and this is as little as possible.
Three words. Doomed Accord Hybrid.
It had 20hp electric motor with a V6 as well.
I hope they reveal the emission reduction as well. Accord Hybrid made no improvement in emission using the same setup.
well the accord was definitely the wrong hybrid at the wrong time.
also, these are lithium hybrids.
when gm rolls out their new BAS hybrids with lithium they expect at least a 20 percent improvement in fuel economy. if they can do this cost effectively I think it will sell.
this mercedes is said to achieve a 15 percent increase in fuel economy. better fuel economy will result in lower emissions.
Not necessarily. GM two-mode SUV hybrids actually pollute more (per EPA standard) than non-hybrid version yet they get higher MPG.
http://www.gm.com/experience/fuel_economy/altfuel/emissions/50state/pdf/2008MY.pdf?exist=false
The non-hybrid Yukon has ULEV2 emission rating while Yukon 2-mode hybrid has Bin5/LEV2 higher emission.
Dennis - By that same reasoning the Ford Focus is just as green as the Prius. The emission ratings you reference are only fuel systems emissions, which are essentially emissions that leak out of the engine, gas cap, etc. If you are speaking to CO2 emissions, then fuel economy is essentially the standard.
It is more than gas fumes escaping from the cap. The difference between LEV2 and ULEV2 are the NMOG and CO2 from the tail pipe. Since we know Yukon hybrid has lower CO2, it must be the NMOG increase that attributed to the change in emission standard. We are talking about 64% NMOG increase from the tail pipe exhaust between the two standard. I hope BMW pays attention all type of emission from the tail pipe and not make the same mistake.
Diesel engines produce less CO2 compare to gas engines but they are much higher in NOx, HC, etc... solving part of the solution.
Focus PZEV reduces SMOG related emission but increases CO2... again solving partial problem is not the solution.
The real full solution is to reduce all types of emission while increasing MPG. We know Hybrid Synergy Drive has been proven to be the solution instead of pollution.
Can E-FLEX achieve the same? Without the use of Atkinson cycle, I doubt it as that combustion cycle is cleaner.
well i think that if people are going to use the Volt, or some other E Flex vehicle in the future, consistently beyond its electric capabilities, then the Volt probably isn't the best solution for either fuel economy savings or pollution.
also, with BMW, this technology is supposed to eventually make its way into a diesel hybrid configuration as well. in either case, i'd assume that BMW is very focused on emissions with this vehicle as the EU has definitely been rattling its global warming saber much more than the US.
Li-ion is a great buzz word, but not that helpful in of itself. They are about half the weight of NimH, at about twice the cost. For the small packs used in non-pluggable hybrids, that weight difference is fairly negligible. For example the Prius battery weighs 80 lbs, cutting that in half would have almost no effect. Doubling its capacity for the same weight would have very little effect either. As long as a hybrid battery has enough capacity to capture and release energy stored in normal stop and go driving more battery won't be much help. The Prius already has enough, as its been demonstrated that you can double the battery or cut it in half without affecting mileage under normal driving conditions. You also need a battery that can charge and discharge quickly to make efficient use of that energy. The Prius NimH can already charge at >10 times its capacity (>60A) and discharge at >15 time capacity (>100A). Thats already better than most Li-ion currently offered, and approaching diminishing returns.
as a big fan of the Prius, I don't necessarily disagree with what you are saying, but most analysts agree that economies of scale look better for lithium technology than for NiMH technology. so, in the long run, lithium does potentially offer a significant cost benefit. for non plug-ins, i think this is where the real advantage lies, in addition to smaller packages which give designers more room to create more functional hybrids.
even toyota, which has invested a massive amount of money in NiMH battery technology, was very interested in converting non-plug-in Prii into lithium powered hybrids. they still are and reports leaking out of Toyota indicated that the lithium hybrids that toyota was testing were achieving a fairly significant increase in fuel economy without plugging in.
Emissions ratings most deal with what comes out of the tailpipe, though evaporative emissions are considered. Evaporative requirements are very strict until you start talking about CA's PZEV standards. MPGs are an important factor in emissions, as they are measured in g/mi. The more gallons of fuel a car uses per mile, the more stuff one would expect to come out of the tailpipe. This is very true with CO2, but other emissions, CO, NOx, NMOGs etc that contribute to smog and breathing problems vary greatly with the tuning and emisisons equipment on the vehicle. There can also be a lot of variation within a bin, you have to look at the actual test results to see more detail.
For example, a 34mpg Camry Hybrid is generally cleaner (not counting CO2) than a 46 mpg Prius. This is mostly due to it being a newer design, with newer emissions controls. Expectations are that the new Prius due next year will catch up.
Emission --Prius -- CamryHy
CO --------- 0.1 ---- 0.0
NOx ------- 0.01 ---- 0.01
NMOG ----- 0.009 --- 0.006
Sadly it is true that GMs hybrids are all much dirtier than their counterparts. Here are a few examples:
Emission --CamryHy --MalibuHy
CO --------- 0.0 ----- 0.6
NOx ------- 0.01 ---- 0.05
NMOG ----- 0.006 --- 0.037
Emission --EscapeHy -- VueHy
CO --------- 0.1 ------ 2.4
NOx ------- 0.02 ----- 0.04
NMOG ----- 0.006 ---- 0.062
Somewhat shockingly, the Vue Hybrids CO and NOx numbers are actually worse than the H3. The Malibu Hybrid's numbers are also worse than the non-hybrid Accord, Camry, and V6 Dodge Magnum.
I think it's important to note that the Vue and Malibu hybrids are currently mild hybrids.
OK, I'm gonna be mean and sarcastic for a second. Since Bob Lutz doesn't believe in the whole man-caused global warming theory, i guess we shouldn't be surprised by these results. I know that's not totally relevant in this conversation, but I just had to throw it in there.
Mild is putting it mildly :-)
Not that GMs non-mild Hybrids do that much better. The Tahoe 4WD Hybrid improves efficiency (reduces fuel consumption) by 30% in city, and 5% on the highway for a 19.9% combined improvement. To accomplish this they have to grow the engine from 5.3L to 6.0L, degrade emissions from T2B4 to T2B5, and the hybrid is still slower than the standard 5.3L.
In contrast, the Toyota Highlander 4WD Hybrid improves city fuel consumption by 37%, and highway by 8% for a combined 26.9% improvement. At the same time the engine gets smaller, from 3.5L down to 3.3L, emissions get better, from T2B5 down to T2B3, and the hybrid is still faster than the non-hybrid.
Can't say I'm too impressed by 2-mode.
well, the dual mode was designed for people whom actually need full sized SUV functionality - something most owners don't actually, regularly need - such as towing or carrying heavy payloads. these are the conditions when the 2 mode hybrid powertrain excels. when you aren't doing these tasks, however, much of the dual mode hybrid functionality is wasted, which is why GM isn't in any rush to make dual mode hybrid cars, its like paying for functionality not needed.
We'll see how the clutches in 2-mode transmission will last.
I just saw another use for the 2-mode in NYC today. It is being used as a T&L (Taxi Limo) SUV! At least it's 20 MPG is better than 15 MPG Crown Vics.
and now that the cadillac escalade hybrid is out there'll be a new taxi/limo for the very rich as well!! 20 miles per gallon has never been so green and cool.
i guess it's progress, not much, but progress. i think.
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