Diesel SkyACTIV-D Coming to Mazda6

By mid-2013, Mazda will be offering a diesel engine sedan in the U.S. market, the first diesel car from an Asian manufacturer here in recent times. The Mazda 2.2-liter SkyACTIVE-D diesel engine will be available in the all-new 2014 Mazda6 along with a 2.5-liter SKYACTIV-G gasoline engine, the latter coming first. Both engines can be mated with either the SkyACTIV-Drive six-speed automatic or SkyACTIV-MT six-speed manual transmission.

Compared to the 2.2-liter MZR diesel engine already powering Mazda models in other markets, U.S. bound Madza6 variants get the more advanced – and 10 percent lighter – 2.2-liter SkyACTIV-D diesel that develops greater torque.

Other improvements include a 20 percent reduction in internal friction and improved fuel economy. The SkyACTIV-D features a new two-stage turbocharger and a 14:1 compression ratio, much lower compression than typical diesels.

Mazda says this low compression ratio results in cleaner burning with lower nitrogen oxides, producing virtually no soot. This means no additional NOx aftertreatment is needed, as is the case with many other modern diesel engines.

The 2014 Mazda6 is first production vehicle to feature Mazda’s unique i-ELOOP (‘Intelligent Energy Loop’) braking regeneration system. Unlike virtually every other regenerative braking system that uses batteries to store electrical energy created during braking or coast-down, i-ELOOP uses a capacitor for energy storage. The recouped electrical energy is used to power all Mazda6 electrical systems.

Among its advantages is that i-ELOOP avoids the need for a dedicated electric motor and battery, making the system more efficient, compact, and lighter than traditional regenerative braking systems. Also, capacitors can charge and discharge rapidly and are resistant to deterioration even in prolonged use.