California is a critical state for Mazda. Robert Davis, Senior Vice President for U.S. Operations, reminds me that they are headquartered in California, so he knows the California Air Resources Board (CARB) emissions requirements all too well. “We’re a smaller manufacturer, so the ability to meet the requirements they give us are a little bit more challenging.”

It’s one of the biggest reasons car companies are creating gasoline direct injection engines. CARB will tell you that the Federal Government would not be as hard on the automobile companies as they are if CARB were not the initiators of the emission requirements. California created the Clean Air Act, so the state will get pretty much any waiver it wants from the Federal EPA, which means the car companies pay a lot of attention to any rule the California Government tries to set forth.

Which is why Mazda made the announcement at the Los Angeles Auto Show that, in the second half of 2013, the Mazda6 will be available with Mazda’s SKYACTIV diesel technology. Not only is this 2.2-liter a diesel direct injection turbo, but it is also an ultra-low compression diesel engine, which Davis says will allow Mazda to manage some of the requirements of the CARB emissions statutes.

The gasoline direct injection compression is 13:1, which is unheard of in this segment. Soon, Mazda will bring their diesel variant which is 14.5:1 compression rate. The Volkswagen Jetta diesel 2.0-liter engine’s compression ratio is 16.5:1. Why would Mazda take their diesel compression down to 14.5:1 and their gasoline compression ratio up to 13:1?

Ruben Archilla, Group Manager of Research & Design for Mazda North America, explained that Mazda is a small car company. Mazda figured out that they can beat the economies of scale if they machine the block in the same plant. In order to do that the compression needed to be as close together as possible.

The SKYACTIV gas engines (all sizes), SKYACTIV-D 2.2L, and the Cyclone V6 are all machined and assembled on the same mixed line at the Ujina plant. Because Mazda paid attention to this detail, the block machining time decreased from 6.0 to 1.3 hours. Archilla noted that the same standard Computer Numerical Control (CNC) machining stations used for block machining can also be used for machining transmission housings.