What you need to know about the fourth-generation Miata, the ND, was it was never supposed to get a 2.0-liter engine. Mazda engineered the ND to feel as close to the original 1.6-liter Miata as possible, which meant examining every single place the car could be smaller and lighter. Including the engine, which lead Mazda engineers to choose a 1.5-liter 130-hp four-cylinder for its sports car.
"That was the argument for the 1.5," Dave Coleman, engineering manager for Mazda North America told me. "The best one that we've ever made was the least powerful. We don't need a bunch of power, right?"
Mazda uses that 1.5-liter Skyactiv engine in other cars, but it was heavily reworked for duty in the Miata. The result, I'm told, spins beautifully to its 7500-rpm limiter and suits the lightweight character of the ND perfectly.
But Coleman knew 1.5 liters wouldn't be enough for the US. In Japan, where traffic is generally slower and less aggressive? Sure, but not here. He strongly advocated for the 2.0-liter, and Mazda bosses relented. But, that decision came towards the end of the ND's development, which ended up meaning the big engine didn't get nearly as much finessing as the 1.5.
There isn't anything wrong with the ND Miata's original 2.0-liter—it's got great throttle response, and a nice broad torque curve. But insiders—including Coleman—knew the 1.5 was better. Mazda put so much work into taking the Miata back to its roots, and the tiny, zingy engine was a huge part of that. So shortly after the ND launched, the engineers went back to the drawing board to give the 2.0-liter the attention it never originally got.
Mazda brought me out to California to sample the results over two days driving between Pismo Beach and San Francisco, a couple hundred miles on the roads the Miata was created for. It was a good couple of days.
The 2019 is the most powerful Miata ever. With 181 hp, it even eclipses the 2005-2006 Mazdaspeed, the only Miata to come turbocharged from the factory. This was an accident.
"All throughout the development, this engine's purpose was high revs, high revs, high revs" Coleman said. "Nobody even mentioned how much power it was gonna make. We didn't know how much power it was going to make. That wasn't the point."
One-hundred eighty-one horsepower is just what you get when you take the powerband of the ND Miata's old 2.0-liter—which made 155 hp and topped out at 6800 rpm—and lengthen it. Without any timing gear, the extra power makes the car feel noticeably quicker, especially the soft-top, which weighs 113 lbs less than the folding-metal-roof RF.
But I'm not terribly interested in acceleration. Though it's certainly better in this car, the Miata's never been about sheer straight-line speed, and the benefits this engine brings are so much greater than numbers on a stopwatch.
Where the previous ND 2.0 made peak power at 6000 rpm, tapering off towards its 6800 rpm redline, the new engine makes all its power at 7000 and pulls hard to its 7500-rpm redline. And it's buttery smooth doing so, thanks to lighter internals, and a stiffer crankshaft.
Now, there's a bit of controversy about the redline—Grassroots Motorsports drove a 2019 Miata and , which was confirmed on a dyno. A Mazda spokesperson later clarified that the car only revs to 7500 rpm in aggressive driving conditions—otherwise, it cuts out at 7200 rpm. I never noticed it, so I suppose I was driving fairly aggressively.
Some thought this engine felt like an old naturally aspirated Honda engine, but I disagree. Drive an S2000, and there's a very pronounced step when the cam profile changes; here, the power is totally linear from about idle all the way to redline. In this way, it actually reminds me of an air-cooled Porsche flat-six. And like an old 911 mill, this engine loves to live near redline—leave it between 6000 and 7500 rpm and it's perfectly happy.
The power curve should give more flexibility on back roads and on track. Where before fourth or even fifth were needed to avoid running into the rev limiter, now, lower gears will do the trick just fine. Automatic Miatas with this engine get a shorter final drive, but gearing remains the same for manual-transmission cars. Coleman says the gearing was originally optimized for the 1.5-liter, so the ratios suit this new 2.0-liter better.
Mazda also worked on refinement. Previously, the ND Miata used a single-mass flywheel for better response at the expense of increased gearbox noise. It never bothered us, but apparently some people cared. An off-the-shelf dual-mass flywheel wouldn't work, though, so Mazda worked hard to create a new, low-inertia unit. In terms of response, this flywheel gives up nothing to the old single-mass unit, so don't think Mazda is prioritizing refinement over purity.
It's been a while since I've been this excited about a four-cylinder. The inline-four is more common—and more boring—than ever. The automotive world is filled with new four-cylinders (often turbocharged) and they all feel the same. Effective, but totally anodyne. This motor isn't. Mazda really worked to make it feel special like the best sports car engines of old. Think Alfa Romeo or Lotus-Ford twin-cam to get an idea of what I mean.
The response, smoothness and linearity of this engine are unparalleled in modern four-cylinders. And because it sits in an ND Miata, it's part of a complete package.
Mazda didn't change much else for the 2019 Miata, and really, it didn't need to. Already, the ND was one of the best sports cars on the market regardless of price, and this engine makes it better. You still get steering with real feel, world-class brakes, a perfect shifter, and a compliant chassis that loves bumpy, cambered back roads.
Besides the engine, the only major changes are a now federally mandated backup camera, a new exhaust system for better sound, and a telescoping steering column, the first in a Miata. Mazda worked hard to make sure this new steering column setup weighed just half a pound more than before, while giving up nothing in terms of rigidity.
There's also a new trim—GT-S. It's essentially a more luxurious Grand Touring model with the stiffer suspension and limited-slip differential of the Club model. I still think the sweet-spot is the Club with the optional BBS/Brembo/Recaro package, which gets you gorgeous wheels, better brakes, and comfortable, supportive seats.
The ND Miata was a revelation when it came out. As the world moved towards increasingly complicated, heavy performance cars, the ND was a simple, lightweight gift to enthusiasts everywhere. A car that prioritized feel, fun, and usability over everything else. This engine bolsters what Mazda got so, so right with the ND. Few modern sports cars are so joyous, and now, it comes with a truly special engine.