The best way to harvest what is essentially 'free' engine power under braking or when running on a trailing throttle for example, has challenged engineers for decades.
The most common solution is brake energy regeneration: capturing kinetic energy that would otherwise be lost when slowing down. Such systems have been in use for some years - Formula One racing cars started to use them in 2009 - but Mazda's system is unique.
i-ELOOP (short for 'intelligent Energy Loop') is the world's first passenger car system to use a capacitor to store the electricity. The all-new Mazda6 is the first of Mazda's SKYACTIV technology models to be available with i-ELOOP.