We get it – we're a little sick of getting a few years of assurances that Mazda's much-anticipated diesel engine is just around the corner. First, it was going to go in the 2014 Mazda6, then it was delayed. More recently, Mazda told us it'd first land in the CX-5 – and in fact, there's a part of the Mazda USA website devoted to the diesel crossover, which makes it seem more legitimate than previous pronouncements. But the fact of the matter is, there's some unforeseen hiccup in the government approval process for this engine, likely centered around emissions standards, and it seems to be dragging on. But this Mazda6 was spotted at an EPA facility in Michigan, which gives us some hope that perhaps the company is rounding the final base on the approval process.
It looks very much like an American-spec Mazda6 to our eyes ... except for the strange, possibly temporary exhaust outlets, which might be required for EPA testing. The rear looks like a current-look car, rather than the revised 2018 styling that will get the 2.5-liter turbocharged gas engine. Since the Mazda6 was originally supposed to get the Skyactiv-D engine, we can only assume that if it's at an EPA facility, Mazda is hoping to bring it to market here – likely sometime after the CX-5 goes on sale.
If Mazda can get approval, it'll be another point of differentiation between the Mazda6 and its competitors – there's no currently-approved diesel sedan that's a direct match. The smaller Cruze and larger, more expensive offerings from BMW and Jaguar are about it.
The fuel economy guide (PDF) produced by the EPA back in late 2017 lists both the CX-5 and the Mazda6 as having diesel engines, but neither are rated, and as we know at this point, neither are on sale or have an official timeline for doing so. We can assume anything with an application in progress made it on the list, whether approval would be granted or not.
It seems unlikely at this point that Mazda would abandon the Skyactiv-D in America. It's a solid part of their strategy, although a product roadmap released a few months ago shows that Mazda expects diesel sales globally to taper off after 2020, to be supplanted by plug-in gas hybrid, EV, and fuel cell vehicles. But between now and about 2030, pure diesel cars are expected to be a small but significant portion of Mazda's product mix.
