Where Are the Micro-Hybrids?

August 26, 2009

With all the recent buzz and federal dollars going to all-electric cars, the opposite—and more practical and affordable—end of the gas-electric spectrum is missing in action in the United States. Micro-hybrids, also known as start-stop systems, use regenerative braking and battery storage to allow cars not to burn fuel while at a stop. Cars using stop-start do not provide propulsion to the wheels, but the technology is low hanging fruit—a cheap and easy way to get about 10 percent more miles per gallon. The cost of a micro-hybrid system can be as low as $500 per vehicle.

Automotive News reported this week that Mazda is struggling to bring micro-hybrids to the US. The company says its system, called i-stop, is good for a 10 percent fuel economy improvement in big city driving, but complained that the US Environmental Protection Agency does not account for the system’s benefits in emissions and mileage testing. Could America’s environmental agency be the stumbling block to bringing a technology to market that some observers think should be required as standard equipment?

Europe sees micro-hybrids as a key strategy for reaching stricter emission standards. Industry analysts forecast that micro-hybrids will exceed all other forms of gas-electric technology. More than 1 million vehicles could use micro-hybrid technology in 2010. Strategy Analytics Automotive Electronics Service forecasts that global sales of stop-start micro-hybrid systems will reach nearly 20 million units a year by 2015. Auto supplier Bosch has sold more than a half-million stop-start systems to BMW, which offers the system as standard equipment in its 1-series vehicles. Supplier Valeo—which estimates that in cities, cars spend up to one-third of their time idling at a standstill—announced last year that it agreed to supply 1 million systems to PSA Peugeot-Citroën by 2011.

A micro-hybrid is the simplest kind of gas-electric technology. It is commonly composed of an energy storage device—like a battery—and a beefed-up starter-motor that can also act as a generator. The car’s engine control unit shuts off the engine when the car slows down or comes to a stop. As soon as the driver puts in the clutch, moves the shift lever, or accelerates, the battery powers the starter motor, which quickly switches on the engine. Stopping the engine while vehicle is at idle conserves fuel, but one disadvantage to this type of system can be the noticeable starting and stopping of the engine.

Mazda’s ”i-stop” uses a different approach, restarting the engine through combustion. Mazda’s system initiates engine restart by injecting fuel directly into a cylinder while the engine is stopped, and igniting it to generate downward piston force.

The upcoming 2009 Frankfurt Auto Show will debut the BMW 320d diesel vehicle and Kia Venga, which will both use stop-start. Europe has so many cars with stop-start that the UK’s AutoExpress recently did a “shoot out” comparing the systems. The BMW 320d beat out its competition—including the Volkswagen Passat BlueMotion diesel, Toyota Auris (sold as a Corolla hatchback elsewhere), Mini Cooper, Citroen C2, and Smart ForTwo.

AutoExpress described the BMW 320d’s stop-start performance: “When you come to a halt at a red traffic light, select neutral and take your foot off the clutch. The power is cut quietly, and you’re left to wait in vibration-free silence.”

In the US, it’s the automakers that are silent. General Motors flirted with micro-hybrid technology in its first hybrid pickups, as well as the early version of its Saturn hybrids. But with the discontinuation of the company’s mild hybrids, the US market is lacking a single micro-hybrid.


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  • mls21

    Does anyone know how these systems work when the air conditioning is running at max capacity? Sitting in grid lock in August is a pretty common occurrence. Without the engine running, the AC doesn’t work well, and draws a heavy load off the battery.

    I’m guessing you can just disable the system when the weather doesn’t permit it. Hopefully I wouldn’t have to hold in the clutch to keep that from happening…

  • mls21

    I decided to answer my own question. I got this from Wikipedia:

    “Since automobile accessories like air conditioners and water pumps have typically been designed to run off a serpentine belt on the engine, those systems must be redesigned to function properly when the engine is turned off. Typically, an electric motor is used to power these devices instead.”

    Sounds like a no-brainer to me.

  • Dom

    I REALLY like the fact that the European micro-hybrid (start-stop) systems work well with manual transmissions, something I feel is sadly lacking in most US hybrids. It also makes sense for diesel vehicles, as they can get some of the benefits of hybrids without the additional cost added on top of the extra cost of the diesel engine.

  • steved28

    The AC in my Altima hybrid is icy cold. It’s all electric. I like it better than the belt driven compressors, which always seemed to lack output when my old ICE car or truck was stopped at idle. The AC in the Altima is just as cold when the engine is off as when it’s running, and you don’t have to overcome all that engine heat that typically emits from a stopped vehicle in hot weather.

  • veek

    General Motors spent many millions developing this type of system, it was heavily advertised, it delivered a high percentage EPA economy gain, and yet it obviously failed, due to “poor sales.” Have their marketing people (or any other experts) explained why it did not succeed? This might help others understand how to bring more successful micro-hybrids to market.

  • ex-EV1 driver

    Of course Micro-Hybrids will be popular with the existing ICE-based industry: They won’t have to do anything except more of the status-quo.
    What we need is something different from the status-quo and I have a feeling that the American people realize this.
    Why spend a few bucks extra to get insignificant benefit from a start-stop ‘hybrid’?
    Anyone who really cares will be willing to pay more to actually get something that provides more. Those who don’t care won’t pay anything for anything extra.

  • alancamp

    It sounds like they are trying to ‘sell’ the concept of ‘micro hybrid’. It’s not gonna fly. Soon they will want to call a car a micro hybrid because of the amount of tail wind it accumulates. Start stop does not make the car a hybrid. If that was the case, all cars would be hybrid since we all start our cars, and then stop them, then start them again. If an obese person lost 100lbs, they can increase fuel economy by 10% also, so then every car they drive will be a micro hybrid. I think the consumer who is looking to actually buy a hybrid vehicle, is looking for something more than just a hybrid sticker on the car.

  • Samie

    Too late? ex-EV1 driver is right the willingness to pay for 1.6 -3mpgs @ 10% is becoming irrelevant. Why would anyone apply this to small cars? We are going to see EV’s along w/ improvements in standard hybrids so I’m not sure what the extra $500 gains in overall consumer preferences. I have doubts that some manufactures are really doing a cost & benefit analysis on some of these technologies or finding out how much consumers are willing to pay for extra mpgs & if they are willing to pay how many more mpgs is required to actually make it a benefit in overall consumer preferences? This kind of stuff is not hard to do.

  • X_man

    The mazda3 seems very intersting but since its not going to offered in the U.S. thats a big downfall for many mazda lovers and people who are interseted in the car very much.

  • Dan L

    Micro-Hybrid is a nice feature. I’d rather have Micro-Hybrid than no hybrid. But it is a small feature, like power windows, cruise control, or a roof rack. To make this the main selling point of the car is an insult to the buyer. I think that many buyers stayed away because they realized that they were being insulted.

    Seriously, what did they think we’d say? Wow! This car is so advanced that it turns off at stop lights! The overall fuel economy is improved by almost two percent! My search is over! I’ m not leaving the lot ’til I own this baby!

  • simon@syd

    I keep having this thought – what if someone was to sell a kit? Could a $500 kit be applied retrospectively to cars? Probably not. But imagine that – then the whole fleet could be getting that 10% increase in efficiency!

  • Kit for Micro hybrid?

    @simon@sid
    I doubt that a kit will be soon availible for several reasons.
    Depending on the ICE-Design a beefed-up starter will not fit until you exchange some other parts around. This may be a major redesign.
    To do the stop – a lot of things have to be monitored. Some sensors could be necessary – depending on the place where the sensor is placed – also a major redesign
    You need a lot of control software, this is the brain for the system. I doubt that any carmaker will sell the software for self falshing the engine control unit.

    @mls21: the all electric AC is a little more expensive as the belt driven one. So do not expect a lot of them in the mild hybrid sector. Usually the ICE does not stop when AC is on max cool. (and there may be several more restrictions which prevent the ICE to stop)

  • marco

    To the hybridcars journalist

    In Europe no one call the Start and stop system as hybrid, the only car that confuse this term is the smart. Its called smart mhd, which was prompted as micro hybrid.
    Because to be considered as hybrid the electric engine has to help the car, and in this case there is no additional engine.

    The start and stop system which is currently ín cars does not stop the system with the ac on, even in slow mode. This only happens in one car BMW 730.

    From my experience, the problem is when the car turns on again it looks like you start the car. with all the vibration associated, and on high traffic zone is quite unpleasant.

  • Nelson Lu

    I have a few thoughts about this article, which, as I’ll explain below, I believe is misguided in thinking that “microhybrids” (as the article puts it, and which apparently the article felt to be a better-sounding term than “mild hybrids”) is a viable “hybrid option” (as opposed to a viable “conventional ICE option”). The technology isn’t bad; it’s just misleading and market-ineffective to market them as hybrids, micro- or mild or otherwise.

    But I’ll start with the question that has been posed by others — why did GM fail so miserably at marketing cars with this technology? I think it’s a matter of failure of imagination and failure to package the technology correctly.

    I’ll take my own experience — a year and a half ago, I was starting the process of planning to replace my car. I looked at my various options and one of the vehicles I looked at was a Chevrolet Malibu Hybrid. Not a bad car at all, but it came in a nearly one-package-fits-all configuration that lacked some really necessary things for me:

    1) it lacked passenger handles;
    2) it lacked a power seat (later remedied by GM);
    3) it lacked a hands-off cell phone system unless you switch to GM’s integrated system with OnStar (which required getting a new phone number); and –
    4) worst of all, it lacked a spare tire, apparently to save weight; rather, it used a “tire repair kit,” which made me thoroughly uncomfortable about driving the car on a lengthy commute that passed through rural areas.

    (GM should not be blamed alone for that last misstep; Honda did the same thing with the Accord Hybrid, which eventually the market rejected as well.)

    In essence, the Malibu Hybrid, as I said above, isn’t a bad car, but it paled in comparison in experience with the other options that I looked at (which included the Toyota Camry Hybrid and the Nissan Altima Hybrid). Ultimately, I decided to wait for a Ford Fusion Hybrid (since I liked the conventional Fusion but wanted to get a hybrid). I am about 12K miles into the vehicle, and the Ford Fusion is simply far nicer as a car.

    And that leads back to the issue why I think the technology ultimately is a losing one as a “hybrid option” as opposed to “conventional ICE option” in the marketplace. GM might have marketed it poorly, but there was only so much they could do with it. To have even an appreciable fuel-efficiency gain that would even catch people’s attention, they had to find ways to reduce the weight — and that led to the ill-advised no-spare-tire configuration. GM also opted not to go with an electric HVAC system — which might not be viable without a sufficiently large battery — which meant that the efficiency gain was even more marginal when HVAC is on. Sure, one can leave the HVAC off entirely for more efficiency in any car (that includes the electric HVAC systems in the Fusion, the Altima, and the Prius), but that ruins the driving experience.

    Another carmaker might do things differently, and as has been noted elsewhere online, the BMW 1-series can be considered a mild hybrid in some ways (although BMW avoided calling it one), and is doing moderately well. But the 1-series provided an extremely small fuel efficiency gain compared to its similarly-sized brethren, and BMW would have failed miserably marketing it as a green car, since it wouldn’t look like one at all when one looks at its fuel efficiency figures. I am all for incremental gains as far as efficiency is concerned, but it will draw no traction in the marketplace when the efficiency is not appreciable in numbers. (And for me, the 1-series was too small and too expensive (for its size, that is).)

    Yes, I would applaud Mazda’s stop-start system even if it brought no MPG improvement figures; it will simply be good for the environment incrementally. But it is not a replacement for hybrids and other technology even more efficient than hybrids.

  • Samie

    Car manufactures should take note to people like Nelson Lu’s car buying experiences. Sometimes people w/i the auto industry can’t do a good job evaluating real consumer preferences.

    -2010 Chevy Hybrid Malibu 24-25k EPA 26-mpg city and 34-mpg highway

    -2010 Chevy Malibu 22k-23K but LTZ cost more…. EPA 22 city & 30-33 highway

    So the point here is the Two-mode added about 2k to the cost & gave consumers no real gains in highway mpgs & marginal returns for city driving.

    Looking at other Hybrids (2010 Ford Fusion Hybrid, Camry Hybrid, & Altima Hybrid) you can see no real mpg gains in highway miles but city driving gave 7 to 15 mpgs more from these competitors. See http://www.caranddriver.com/reviews/comparisons/09q1/2010_ford_fusion_hybrid_vs._camry_hybrid_altima_hybrid_and_malibu_hybrid-comparison_tests

    All have similar pricing for their hybrid models. I’m not sure if these other hybrids do or do not have donuts but you can see GM failed at justifying added costs to consumers who were in the market for hybrid sedans.

    The next gen of Two mode has to be better or else again it will fail. Cost is a issue too. We seen this on some of GM’s SUV models the mild-hybrid added 6-9K more. Also before the death of the current two-mode system there really was little improvement in efficiency or cost (larger SUV’s) over the time frame of this system. I think the Malibu is a great car but as others have said I don’t think consumers are being fooled by poor attempts at hybrid branding. This is why again I don’t understand the attempts to find out consumer preferences before investing millions into R&D that ends up being a wash. For GM I’m concerned that management doesn’t get it, they are wasting money into projects consumers won’t buy or don’t care about (eg. E85 or Hydrogen) & I doubt GM will have the capital to invest into improving the Volt or finding ways to reduce its cost. There are people in the auto industry that are 100x smarter than I but I wonder sometimes if they really get it or are some just living in a bubble?

  • Skeptic

    As others have noted, these are not hybrids. They are a fine idea and, really, need to be in all cars, but hybrid? Not.

    Repeat after me:

    “AUTO STOP-START IS NOT ‘HYBRID’”
    “AUTO STOP-START IS NOT ‘HYBRID’”
    “AUTO STOP-START IS NOT ‘HYBRID’”
    “AUTO STOP-START IS NOT ‘HYBRID’”

    Thank you.

  • ex-EV1 driver

    Skeptic,
    There’s really no need for you to try to convince people to follow your mantra. Clearly, judging from the sales of GM’s ‘hybrids’ compared with Toyota, Honda, Nissan, and Ford’s, people already get that Auto Stop-Start is not a Hybrid.

  • ROY STEWARD

    I drive a Cadillac DeVille. The car gets about 24MPG on the highway which is quite remarkable. The MPG reading is 24 MPG at 30MPH and 26 MPG at 50 MPH. In town, the car averages about 14-15 MPG. Obiously the gas is being “wasted” on idling and acceleration. An inexpensive “mild hybrid” system to eliminate idling losses and attenuate acceleraton losses would be especially usefull on this car. I would guess that the MPG could be about 20 with a well designed system, whatever you choose to call it. I think the automotive media did a disservice to us all by criticizing GM for their “mild hybrid” efforts over the past several years. There is room for a 20 MPG DeVille mild hybrid, a 45 MPG Fusion hybrid, a 50 MPG Prius and an “x” MPG Volt. The 20 MPG DeVille might have the best payback for the price premium associated with the hybrid.

  • Csaba

    If the motor has 1) starter-motor that can also act as a generator connected directly to the gearbox or motor and 2) has regenerative breaking then it is a hybrid, although µ-hybrid.

    This is low hanging fruit. It can be produced NOW without waiting for some break through like battery-prices. It can give up to 10% reduction of gas consumption NOW. And a combined starter-motor and generator maybe will increase cost $100 or less than a separate generator and starter-motor.

    Only when battrey prices has dropped 75% will plug-in hybrids become common.

    So µ-hubrid is good, regardless of what some people here write. I think this will be come standard in Europe within three years.

  • veek

    Regarding the requests to retrofit the microhybrid system: Howz about saving $500 and just shut the engine off at prolonged stops? If you want you can even put in a reminder light that comes on when the car is not moving! I stopped my car’s engine while in traffic several months ago (and even shut the engine off before coming to a stop when I could, which is actually dangerous and not recommended) and noticed no change in my particular car’s fuel consumption over five alternating tanks, so maybe the EPA is right to be skeptical. Regenerative braking is another matter, but unless the battery is made bigger (and costlier), and the battery somehow helps the drive belt run accessories (to avoid overcharging the battery), this would not seem practical.

  • jhon_k

    thank you for writing about Micro-Hybrids.
    convertible cars

  • alessio

    I definitly agree with you

    start stop on a traditional engine only produces more wear and tear and it can also cause alot of cooling and lubrificating problems

    and all belts produce alot of friction!!!

  • Toddy

    I actually enjoy the comments more than the article. Thanks for a great discussion.