By on October 14, 2010

America has always been a land of extremes, and our automotive scene is no different. While current automotive debate obsesses over a high-efficiency halo car, our domestic auto industry is mounting a comeback largely on the back of pickups and large cars and crossovers. Meanwhile, we’re falling behind in the quest to make all cars more efficient with practical “bolt-on” systems like “stop-start” or “microhybrid” systems that turn off gas engines at stops. So what are we missing out on? According to a report from SeekingAlpha, stop-start systems provide

estimated fuel savings range from 5% in government mandated tests and 10% under real world city-highway driving to almost 20% in congested city traffic

Which would provide a hell of a lot more fuel savings than any high-price, limited-production eco-halo car. But, as Mazda has complained, the US EPA test cycle doesn’t provide any Monroney Sticker advantage to stop-start systems, even if they provide real-world improvements in fuel efficiency. Maybe instead of trying to keep EVs and plug-in halos on subsidy life support as long as possible, our government should be looking at ways of incentivizing across-the-board efficiency improvements like those offered by stop-start systems.

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15 Comments on “What’s Wrong With This Picture: Land Of The (Stop-Start) Free Edition...”

  • avatar

    I would love a stop-start system in my car. Most cars these days are pretty efficient on the highway, it is the city mileage that is always much lower. If that could be improved by such a simple system that is also inexpensive, why not? There is a huge premium for hybrid drivetrains that achieve the same result, with virtually no net savings from the reduced fuel consumption due to the higher initial cost. A cheap stop-start system would pay for itself very quickly.

  • avatar

    I’ve wondered for quite a while why more car companies haven’t been adding simple start/stop systems on their cars. It seems like such a no-brainer. If anything, it could leapfrog a manufacturer to the top of the “most fuel efficient fleet” hill by CR or whoever. GM needs to include their start/stop hardware on all their cars and trucks, just DON”T LABEL THEM HYBRIDS! Label them for what they are and watch the average fuel economy rise, which can be marketed to death.

  • avatar

    Spot on!
    In Europe, for instance, the smart is most often, if not always, one of the “micro hybrid drive” type, i.e., start-stop type.
    Not so in the U.S.  Why?  Well, why try a different setup with potential liability, etc., if EPA won’t be acknowledging it?  See, that’s the problem when government mandates the sticker.
    Anyway the other fun fact is that U.S.-market engines purposefully burn high quantities of gasoline (from a cold state) to keep the engine and exhaust hot for catalytic converter/EPA purposes.  In short drives in cold climates in congested cities in the U.S. only, start-stop economy may be harder to attain than what some expect!

  • avatar

    GM offered a stop-start style system for a few years. The 2010 Malibu BAS was rated at 26/34/29 by the EPA, which I believe was the best city mileage rating for any nonhybrid midsizer. So there must be at least some EPA boost for the system.
    However, IIRC, every single person and automotive publication in the US blasted the Malibu/Aura BAS up one side and down the other.

    Part of this is because GM was stupid and put a “hybrid” badge on it, but part of it was because auto publications seem to only care about highway miles and never bothered to test the system in heavy traffic. So we got a lot of “only one MPG better than the 6-speed Malibu!!!!” ranting.

  • avatar

    One of the issues with Stop Start is that the Air conditioning / Heating is disabled. This can be overcome by moving to electric driven ancillaries (like the 3rd Gen Prius) but adds to the cost and increases the required battery capacity, obviously nowhere near a full hybrid cost increase but in a market where many people want a focus sided car for sub $16K something has got to give.

    • 0 avatar

      If there’s no heat or air conditioning available when the engine is off, then it’s quite a stretch to use a term like ‘microhybrid’ for a vehicle that simply does something you can do in any car with which you’re willing to give up interior climate control.  I assumed that ‘microhybrid’ meant that there was at least some energy recovery during braking to power those accessories and maybe get the vehicle rolling again from a stop.  If not, please kill the term.

  • avatar

    How does having automatic stop/start make a car a hybrid, even a ‘mini’ one?
    It does seem like a no-brainer to add this to any modern fuel injected car, except maybe diesels.

  • avatar
    Facebook User

    I’m sure it returns better real-world gas mileage, but being someone who drives at least 1/2 miles during non-rush and has exactly 1 light between the highway & the house (town of 27k) I’m not sure how much it would add to my gas mileage…

  • avatar

    I am guessing that in 5 or so years, you will start to see this on many vehicles.  Fuel economy regs getting tighter, this will help… just got to get this into the testing somehow.

    • 0 avatar

      easy peasy, just add a Drive Thru test cycle.

      America is the land of fast food.

      EPA cycles would then be:

      Drive Thru

      I’d suggest the Drive Through test be normalized to the equivalent of sitting in a drive through with 5 cars waiting taking about 15 minutes to complete (

      City cycle

      * Trip length: 11 miles
      * Test time: 31 minutes
      * Number of stops: 23
      * Time spent idling: approx. 18%
      * Maximum speed: 56 MPH
      * Average speed: 20 MPH
      * Engine temp at startup: Cold (75 degrees outside air temperature)

      Drive Thru Cycle

      * Trip length: 0.01 miles
      * Test time: 15 minutes
      * Number of stops: 7
      * Time spent idling: approx. 98%
      * Maximum speed: 3 MPH
      * Average speed: 0 MPH
      * Engine temp at startup: Warm

      Then just decide what percentage it’d take to make the Drive Thru cycle barely affect the combined mileage. I haven’t done the math but something like 10% Drive Thru/50% City/40% Highway seems reasonable adjust the mix of the 3 tests until the Yukon/Tahoe/Sequoyah look worse without making them look any worse than you have to and without making the Prius look unbelievably better than it is.

      If there is any political backlash on the name “Drive Thru Cycle” call it “Traffic Jam Cycle” instead and bump the max speed up to 13 MPH, lower the idle time to 50%, and increase the Trip length accordingly.

  • avatar

    Combustion interruptus.

  • avatar
    Greg Locock

    Of course there is nothing to stop you manually stopping the engine at each stop, for a week to see if it is worth it.

    I bet you find the fuel savings are minute.

    In my case my car use about 2 pints of fuel per hour when stopped, even with the AC running flat out. SO in my 6 hours of driving a week I spend perhaps 20 minutes at idle, 3/4 of a pint saved out of 6 gallons. Um, every little helps, but color me unimpressed.

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