#idle-stop

Among the many new SKYACTIV technologies that Mazda plans on introducing to its global lineup, a unique start-stop system is one of the most important. Initially Mazda had decided not to bring its idle-stop system to the US as the EPA system didn’t measure a major improvement in efficiency, but ultimately the decision was made to make all of its vehicles idle-free by 2015. But an early test of a SKYACTIV idle-stop-equipped Mazda2 by Automotive News [sub]’s Hans Greimel reveals an interesting characteristic:

a funny thing happened when I paused for a red in Tokyo’s harbor district.

After a few moments of silence, the engine clicked on, as designed, to help keep the air conditioner going. OK, that’s normal. But as the engine jumped to life, so did the steering wheel. To my surprise, I found the engine’s start-up vibrations turning the wheel to-and-fro in my loose grip.

By 2015, no new car made by Mazda will stand around idle. By this year, Mazda plans to install its idling stop function on all of its new automobiles, says today’s Nikkei [sub]. Some domestic and European Mazda already have this feature. In a few years, it will be universal, including North America, where current EPA regulations discourage idle stop.

Idle-stop technology, which turns off a car’s engine instead of idling, is available from a number of automakers in the European and Japanese markets. Mazda claims nearly half of its Mazda3 compacts and Biante minivans sold in Japan are ordered with the $500 option, as consumers seek out fuel economy improvement without the cost of a full hybrid system. So, why doesn’t Mazda sell idle-stop equipped cars in the US? According to the company, though Japanese fuel economy tests show stop-start improving efficiency by seven to nine percent “the EPA city-mode test cycle includes only one complete vehicle stop, so stop-start technology registers only a 0.1- or 0.2-mpg improvement.” And who would pay $500 for that?