By Jim Taylor, Editor MACS ACtion Magazine
The “stop-start” technology that shuts down a car’s engine at a traffic light and then restarts with a touch on the throttle, is just beginning to appear on the North American market. Elsewhere in the world however it’s quite popular, with nearly half of the cars sold in Europe and Asia being equipped with the system. It can be used on both hybrid and normal, liquid fueled engines.
One reason stop-start is not seen here is that until very recently, EPA didn’t include the function in its official MPG testing. Thus, OEMs reasoned, why put it on U.S. cars if it won’t bring the intended benefits; let’s just save the cost.
The costs aren’t huge, and where it is offered as an option in this country, the added amount is often well under $500. That cost, supporters say, can be easily recouped through fuel savings over the life of the car.
One test showed a fuel economy increase of over 10 percent for a vehicle in mostly urban use.
As CAFÉ requirements tighten, car makers are now beginning to offer the system more widely , and versions of the system are scheduled to appear on various products from Ford, Kia, Mercedes-Benz, Toyota, Porsche, Mazda and BMW. For some, it’s included as standard and on others it will be an extra-cost option. Either way, you’ll see much more of this system soon.
And although the systems are quite reliable, overcoming owner objections in the U.S. is proving to be another challenge as well. Many buyers, particularly in the up-scale market, are old enough to equate a car shutting off with “a stalling problem” at lights. No matter how easily the car restarts, they still get a little wobbly without the engine running all time.
BMW thought they had anticipated that problem by equipping their stop-start cars with an override button that can shut the function off during each drive cycle. If the driver didn’t care to save fuel, just detach the system to get normal idling at a stop. Later, when the ignition was next cycled off, the override canceled itself and stop-start benefits were available at the next start-up.
But even with that, they underestimated some of their clients. What the company found is that some owners don’t like having to switch the system off each time they start the car—they expect the override switch to stay engaged all the time.
So BMW has now issued a service bulletin allowing dealers to engage a different operating mode in the control computer upon request. After the update, once the override switch is engaged, the stop-start system will remain off through subsequent driving cycles.
Sometimes the old dogs just won’t learn new tricks.
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