In late August, exactly six next-generation 2020 Mazda 3 hatchbacks existed anywhere in the world. Each was a hand-built prototype, riding on a next-generation chassis and powered by a radical new 2.0-liter engine. We'll take two.
But the car’s styling and design haven’t been revealed—and won’t be until 2019—so the new chassis and powertrain are topped with most of the body shell and interior of today’s Mazda 3 for real-world testing.
We drove two cars August 29, one with a 6-speed manual gearbox and another with a 6-speed automatic transmission.
The six cars bore the signs of engineering prototypes: flat-black body wrap, bolts holding parts of the bodywork on, a re-engineered gas door in an inset metal panel. Only differently colored door mirrors and a large number on the door distinguished them from each other.
Under the hood, a large black plastic engine shroud hides the engine itself, which we saw in static displays. But plenty of underhood zip ties, holding in place the hand-built wiring and plumbing, showed the cars’ developmental status.
Radical new SkyActiv-X engine
The 2.0-liter engine that will arrive for 2020 has been dubbed SkyActiv-X, and it represents a radical leap forward in efficiency over its predecessor.
Mazda, in fact, is on the verge of putting into production an engine that uses the principle of homogeneous charge compression ignition, or HCCI, which has been a holy grail for engine designers for decades.
Mazda’s new 2.0-liter engine is an evolution of the SkyActiv-G inline-4s it began to offer in 2012 models. Using the highest compression ratio of any gasoline engine on the market, at 14 to 1, that engine burned a leaner air-fuel mixture and consumed roughly 20 percent less fuel than engines of similar power from other makers.
The "X" version of SkyActiv takes the next step, raising the compression ratio to "15- or 16-to-1," close to high enough to permit a lean gasoline-air mixture to combust under compression alone.
Previous attempts by other makers at creating engines using HCCI had all used mechanical means to increase the compression ratio further. These ranged from crankshafts that could vary their throw to hinged connecting rods that further increased the compression ratio when actuated.