As automakers look to meet ever more-restrictive emission standards and ever-increasing fuel economy goals, automatic start stop systems, which shut down an engine after a few seconds of idle and then instantly restart it, will become more and more commonplace.
As with any new technology, start stop systems have both fans (who praise the added fuel savings) and detractors (who can’t embrace the idea of sitting in a dead car at a traffic light).
BMW includes the start stop system in its latest 3-Series and M3 models, but drivers have the choice of turning the system off when the car is started via a dash-mounted switch.
On new 3-Series cars, however, the system is only deactivated while the car is running; shut off the ignition, and auto start stop will reactivate by default the next time the car is started.
That’s not exactly popular with BMW drivers in the United States, many of whom have no prior experience with similar systems. BMW dealers have been hit with numerous customer requests to deactivate the system, or to make it stay off instead of on by default.
A new service bulletin from BMW now allows dealerships to program the start stop system into “Last User Mode,” which will eliminate the need to manually deactivate the system (should you choose to do so) each and every time you get behind the wheel. Select “on,” and the system stays on; select “off,” and it stays off on future re-starts.
That makes the 3-Series identical in start stop function to the M3, which comes with “Last User Mode” logic by default.