The fourth generation MX-5 Miata, which Mazda introduced for the 2016 model year, did the unthinkable and lost weight and power when compared to the third-generation car. This not only curbed the Miata’s upward trend, but bucked the trajectory of growth that afflicts almost every new make and model sold today. With the combination of light weight and a great suspension, the Miata didn’t need gobs of horsepower to make an engaging experience for the driver. Yet, even though that’s true, losing 12 hp to just 155 still stung.
The aftermarket jumped to bump the ND Miata’s 2.0-liter inline-four with superchargers and other bolt-on accessories, but Mazda didn’t offer any factory help to increase power. That is, until now. For 2019, the MX-5 gets a new motor with considerably more power. And did so without any forced induction help.
Let’s start with numbers. Mazda bumped the MX-5’s peak output 26 to 181 horsepower at 7,000 rpm — that’s a 17-percent hike for those without a calculator handy. Torque nudges up 3 lb-ft, now 151 at 4,000 rpm. Mazda’s engineers did this without slapping on a supercharger or stuffing a turbocharger under the hood. Nor did they feel the need to increase compression or displacement. Instead, Mazda pulled neat tricks out of a hot rodder’s handbook and focused on airflow to make the engine more efficient, powerful and rev-happy.
Making the kinds of upgrades that Barney Navaro or Vic Edelbrock did to Flathead Fords. Mazda increased the size of the engine’s exhaust port, exhaust valves and exhaust manifold and improved the flow from the combustion chamber to the exhaust. The exhaust manifold has bigger primary tubes and secondary tubes, which helps evacuate all those pesky exhaust gases. On the intake side, there is a bigger throttle body, bigger intake valves and a revised intake manifold with shorter runners and bigger ports. Finally, Mazda increased the lift of the camshaft exhaust lobes to help make better use out of the other improvements.
At the bottom end, Mazda is now using an edge cut piston to help reduce detonation. Mazda also shaved 27 grams of weight from each piston by shortening its skirt and managed to pull 40 grams from each connecting rod. A new, stiffer crankshaft keeps it all together even at its new 7,500 RPM max engine speed, 700 rpm higher than before.
Complementing the new engine, the Miata receives a new exhaust system and a dual-mass flywheel. The flywheel adds weight, but inertia remains the same as the outgoing single mass flywheel, according to Mazda’s engineers, as more of the weight is in the center. Even without any major changes to the six-speed manual transmission, the result is a drivetrain that makes the more powerful engine feel smoother.
Of course, the Miata got more than just a new engine. Mazda added a standard backup camera as well as new black wheels on certain trim levels and a soft-top color option on others. Inside, Mazda added a tilting and telescoping steering column, which, Mazda admits, adds weight, but also makes the car more livable for those with shorter arms. Finally, there’s some added safety available from what Mazda calls i-ACTIVSENSE and includes lane-departure warning and blind-spot monitoring.
Despite the extra oomph, the “slow car fast” mantra still fits the more powerful Miata. That’s a good thing. The freshened engine still feels natural. Power delivery is smooth and linear, with the increased redline welcome to folks who like to rip around tight canyon roads. The 7,500 rpm cutoff also means that you don’t need to shift to third during 0-60 runs.
The additional refinements to the Miata’s powertrain only add to the experience. The dual-mass flywheel makes shifting a manual-equipped Miata even smoother than before. And the new exhaust has a deeper tone, but it's still quiet and subtle. These simple revisions alone would be notable, but the package’s absolute cohesion make the updated Miata holistically splendid.
Whenever a car gets a substantial amount more power without similarly revising the suspension, there’s always a risk of imbalance: an engine that overwhelms the chassis. The Miata doesn’t fall into that camp. You can absolutely feel the extra power, even lower in the rev range, but the engine only complements the Miata’s key characteristics.
For Miata fans, the MX-5's suspension setup happily remains the same. Upfront is a pair of double wishbones and in back is a multilink setup. The Miata’s suspension is largely unchanged because it works. The refreshed Miata feels just as sure-footed as ever. It’s still softly sprung, so the body still leans into corners as lateral load builds. And you can expect dive when slamming on the brakes, too, but all the reactions from the car come as you would expect.
Mazda is introducing a new trim level in the Miata lineup. Called the GT-S package, it’s only available with the six-speed manual and adds more sport to the top-trimmed Grand Touring model. The package includes Bilstein dampers, a shock tower brace and a limited-slip rear differential. It’s offered on both the soft-top and RF models; the latter gets a black roof. There’s still no entry-level sport model of the popular RF edition, which means the most price-friendly version of the Miata is still the soft-top.
It should be mentioned that the Mazda Miata still doesn’t have Apple CarPlay or Android Auto. The 2018 Mazda6 does, so the Miata might get them later, but the 4.6-inch touchscreen displays will only show what Mazda tells them to, for now. The systems work well and are relatively fast. Music sounds great through the standard system, but the optional Bose system helps overcome the Miata’s dropped top.
Adding power doesn’t undermine the Miata’s core mission of letting you drive the car to its limit, which is mercifully low enough to avoid a lasting jail sentence. Mazda added the power in a useful way and made the engine more efficient in the process. The higher engine redline makes the Miata feel like how it should have been built in the first place — it just feels right.
On Sale: Now (RF),
Base Price: $27,000 EST
Powertrain: 2.0-liter I4, RWD, six-speed manual
Output: 181 hp at 7,000 RPM, 151 lb-ft at 4,000 RPM
Curb Weight: 2,339 lbs
Fuel Economy: 26 / 34 / 29 EST(EPA City/Hwy/Combined)
Pros: The new engine happily hangs near redline as you thrash it around corners.
Cons: The media system controller is directly behind the shifter, which makes radio changes hard when a passenger is playing DJ.