With increasing pressure to meet Europe’s new emission regulations by 2020, Mazda is already hard at work on the next generation of its suite of fuel-efficient engines.
Mazda engineers are aiming for a 30 per cent improvement in fuel economy, according to Automotive News. The current crop of SkyActiv engines have been around in North America since 2011. Mitsuo Hitomi, head of powertrain development at Mazda, hasn’t detailed a timeline on these new engines, known as SkyActiv2, but says the next generation must meet tougher European emissions standards of 95 grams per kilometre in 2020.
Hitomi says the improvements are centred around improving internal combustion by boosting the engine’s compression ratio from the current 14:1 in the SkyActiv-G engines, to an even higher 18:1. In addition, Mazda plans to combine this with direct injection and something it calls Homogeneous Charge Compression Ignition (HCCI), similar to a diesel engine. HCCI compresses an engine’s air-fuel mixture to a high enough pressure so that it ignites by itself, eliminating the need for a spark plug. The end result is lower nitrogen oxide emissions and lets Mazda completely overlook CVTs.
In addition to SkyActiv2, Mazda is looking further into the future with SkyActiv3. Hitomi says SkyActiv3 will limit heat fluctuation in the engine’s combustion chamber. Not only would this reduce losses from the exhaust and cooling systems, making more energy availble at the wheels.
Hitomi hasn’t detailed any ballpark efficiency gains with SkyActiv3, but says Mazda is aiming to have it perfected when Europe’s stricter 65 g/km emissions regulations take place in 2025.
