Inspecting the 2014 Mazda Mazda3
by Alain Morin
Photo: Alain Morin
To improve fuel economy the engineers used an external vacuum. At cruising speed, SKYACTIV technology requires the throttle to be three-quarters open rather than the usual one-quarter. However, this would make the brakes less efficient as they work on the vacuum. That’s why there’s an external vacuum (or vacuum pump).