The 124 Spider is powered by Fiat's 1.4 litre MultiAir turbocharged inline-four, producing 140 PS (103 kW; 138 hp) and 240 N·m (177 lb·ft) of torque in European specification—and 160 hp (119 kW; 162 PS) and 184 lb·ft (249 N·m) of torque in North American specification. The 124 manual transmission is from the previous generation Miata’s six speed gearbox to cope with the turbo’s torque.
Multiair is a hydraulically actuated variable valve timing (VVT) engine technology enabling "cylinder by cylinder, stroke by stroke" control of intake air directly via a gasoline engine's inlet valves. Developed by Fiat Powertrain Technologies.
the technology bypasses a primary engine inefficiency: pumping losses caused by restriction of the intake passage by the throttle plate, used to regulate air feeding the cylinders.