That's a pretty big jump from 155 horsepower, nearly matching the larger 2.5-liter engine in the Mazda3 and Mazda6. It's also close in power to the estimates for the Skyactiv-X spark-controlled compression-ignition engine. But, based on what a journalist on Twitter posted, the 2019 Miata will continue to use a version of the existing spark-ignition Skyactiv-G engine. Apparently it will have a new cylinder head, be able to rev higher, and make more horsepower, though he didn't say how much more.
Yesterday I was at the first SkyActiv-X testdrive in Portugal, and Martijn ten Brink (VP Sales at Mazda Motor Europe) has indeed told me that the 2019 MX-5 will receive a 2.0 SkyActiv-G with a reworked head, it will have more power and will be more rev-hungry.— Pierre Desjardins (@PierreDdeG) March 1, 2018
We've reached out to Mazda for comment on this discovery, and, like with most car companies, wouldn't give comment since the topic regards a future product. If it does turn out that Mazda won't up the horsepower for 2019, the good news is that the aftermarket has speed demons covered. Flyin' Miata offers a package that includes camshafts, exhaust and a tune that will bring it up to about 200 hp. There's a supercharger kit from Edelbrock that will provide similar power, but without the need for digging into the engine. Flyin' Miata also offers a turbocharger kit that can bring the Miata up to nearly 250 hp, and if you're really speed-crazed, the company can swap in a Chevy LS V8 with more than 500 hp. Or, you know, you could just be happy with 155.