 even in the midst of America's evolving love affair with crossovers, SUVs, and pickup trucks. For purposes of this review, I'm just talking about the retractable hardtop. Available in two trim levels, the MX-5 Miata RF retractable hardtop is powered by a Skyactiv-G 2-liter gasoline 4-cylinder engine that generates 181 horsepower and 151 foot-pounds of torque.