Mazda?s MX-5 Miata roadster has never been a car consumed with power. In fact, its distinct lack of horsepower is part of its back-to-basics sports-car appeal. The current-generation Miata actually has less output?just 155 ponies!?than the car it replaced. But Road & Track has uncovered evidence that that could soon change.
In an annual VIN notice sent to the National Highway Traffic Safety Administration (NHTSA), Mazda lists the 2019-model-year MX-5 Miata’s engine as a 2.0-liter four-cylinder with 181 horsepower, 26 more than it has now and the most ever from a factory Miata. (The second-generation Miata’s turbocharged Mazdaspeed variant only made 178 horsepower.) How Mazda reaches that number (assuming the NHTSA filing is accurate) is the million-dollar question. The NHTSA document does not specify whether the 2.0-liter engine in question is an evolution of the same Skyactiv-G unit currently in the Miata or something else, like, say, the brand’s forthcoming high-tech gas-fed supercharged, compression-ignition-capable Skyactiv-X engine. The X is slated to appear sometime in the next year or two in the next-generation Mazda 3 compact, and its preliminary output figure roughly matches the 181-hp number listed for the 2019 Miata.

On the other hand, the Skyactiv-G is sticking around throughout the Mazda lineup for the foreseeable future as the entry-level offering positioned beneath the Skyactiv-X. And Mazda has told us it will continue to develop the...