Car magazine has test driven the new MINI Cooper 1.6 with BMW's start/stop technology and likes it a lot. The system on the manual transmission car requires you to put the car in neutral when you come to a stop in order for it to work, which does seem a bit funky to us -- we don't know anyone who puts their car in neutral every time they stop at a light. However, once you learn to do that, you'll get all the benefits of having left your engine running, and you'll increase your fuel economy by about 9%.
The system also only kicks in once the car is up to full operating temperature. If you wish to turn it off (and keep the engine running at all times) there's a button near the gear lever. The MINI also benefits from having an alternator that only charges the battery when necessary, and a light indicator telling the driver when to shift up.
Performance-wise, driven with ultimate economy, the MINI matched Prius CO2 emissions and got -- count 'em -- 74 mpg. Assuming Car uses the Imperial MPG metric, that converts to a still impressive 61 mpg in our U.S. cycle. The zippier Cooper S turned in 46 mpg, or 38 mpg in using the U.S. metric. Even accounting for a drop in real-world mileage, those are still impressive numbers. This is the system that BMW is going to introduce across its entire range, and so far, it's an auspicious beginning.