Tired of Getting Zero Miles Per Gallon? Stop/Start Technology is For You
by Michael Graham Richard, Gatineau, Canada on 02.14.08
Walk, cycle, carpool, take public transit, car-share, telecommute. Try to live close to the things you need and to where you work. But if you have to own a car, get the most efficient model that fills your needs, drive sanely, combine trips, keep it in good mechanical condition and keep your tires properly inflated. That's basically the message that we would repeat in all our car posts if we weren't afraid of becoming redundant... But as long as there are millions and millions of cars out there, we need to look at green(er) cars of the future and at current ways to make our cars more efficient. One of these is stop/start, a relatively simple technology that is unfortunately almost completely absent from North-America (except in hybrids).
The way it works is simple:
When your car comes to a stop, either a red light, a stop sign or in stop-and-go traffic, you are getting zero miles per gallon. But if you had stop/start, which is mainly composed of a bigger starter motor, your car would simply turn off the engine and then restart it almost instantaneously when you take your foot off the brake pedal (or off the clutch in a manual transmission car).
How well does it work? Well, reviewers of the Stop/start Mini Cooper in the UK had this to say:
you can push the button near the gearlever to turn the stop-start system off. But we can't think why you'd want to. It's a simple technology that works seamlessly in the background, and you'll save money by letting it do its thing.
Depending on the car model and type of driving, fuel savings are usually estimated at between 10% and 15%, and stop/start is one of the reasons why hybrids do much better in city rather than highway driving.
You can get stop/start on many Asian and European cars (such as the Citroën C2 and C3, the BMW Mini and the Japanese version of the Yaris), but except in hybrids, it is MIA in North-America. Come on carmakers! At least make it an optional feature!
See also: ::Toyota iQ: Less is More for Small Urban Car, ::Mazda's Smart Idling Stop System, ::Is Your Car Getting Zero Miles Per Gallon?, ::Treehugger Homework: Stop Engine Idling
They are here, but they are widely rejected, even by treehuggers. In the US vehicles with start/stop (BAS), such as the Saturn Greenline models were dismissed as too expensive for the amount of fuel saved or not being "green enough" compared to full hybrids.
Well, GM's implementation *was* too expensive, IMO. I think they tried to do too much for stop-start, but not enough for a hybrid and kind of ended up in between.
Maybe some user-friendly marketing would help: how about simply calling it ... 'Pause'?!
Somewhat more intuitive, don't you think, and self-explanatory? Wouldn't such a renaming help people overcome their fears of the unknown?
I love the idea of "pause". Very nice framing!
Isn't this essentially what the Prius's hybrid system does? Or is it like a Prius that doesn't use the electric motor when it's moving AT ALL?
"10-15% saved doesnt sound like much. Much more could be saved by reducing weight and other gadgnets in the car."
It doesn't have to be one or the other, though. I'll take the 10-15 + whatever else I can save with other techniques.
One reason why we don't see it in NA is the lack of benefit it does to the MPG numbers. It does, however, make a reduction in the CO2 numbers in the UK, which means lower road taxes and a real incentive for the consumer.
10-15% may not sound like much but consider it over 10 years for every vehical - especially things like big trucks.
The stop tech also means cleaner air.
I'm not knocking it, but I am curious about what kind of safety interlocking the system has (for someone that 'thought' they had turned off their car when they get out for exmaple)? Also how does this system work in stop and go traffic? With airconditioning? Keeping engine heat up when in cold weather, etc? If you lock up all four tires on ice does the computer think you are stopped and kill the motor (and your power brakes and steering)?
Having had things like traction control and ABS decide (wrongly) what my car should be doing on snow and ice before, something like this makes me leary...
-Lego
up to 80% of the non-CO2 harmful emmissions of short-trip driving are before the catalytic converter heats up. If the converter cools off again, you'll be dumping another load of CO and NOx, as well as VOCs into the air.
There are many ways to design such systems so they are "smart"; engine won't stop if temps are below a certain level, it can recognize real stops from emergency braking, etc.
It's real concerns, but I doubt it's anything that hasn't already been solved. Such systems have existed since the 80s.
Treehuger had a post a year or two ago about a Japanese add-on kit that would make any vehicle stop/start.
The Yaris has the same engine as my Scion xA. Could I get this "pause" system as an add-on?
My old Subaru can do this. I just turn the key. It helps that I drive the same route all the time and learned the lights, so I know when I'm just stopping for a few seconds of a few minutes.