Multiair

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. Multiair was licensed to the Schaeffler Group in 2001, which also markets the system as Uniair.

FCA, at the time Fiat S.p.A., launched Multiair in 2009 employing a proprietary electro-hydraulic system to precisely control air intake without a throttle valve, in order to increase engine power and torque, reduce fuel consumption, reduce emissions — and improve engine operation — offering "a more controllable flow of air during the combustion cycle in comparison with mechanical VVT systems." The technology allows engines to be lighter and smaller while reducing pumping losses — and can be adapted to existing engines by replacing the camshaft with the Multiair system.

Compatible with both naturally aspirated and forced-induction engines, Multiair technology was patented by Fiat in 2002 and was launched at the 2009 Geneva Motor Show in the Alfa Romeo MiTo. Marketed prominently in Fiat's FIRE engines, e.g., in the Fiat 500²⁰⁰⁷, Multiair engines for global markets are manufactured in Termoli, Italy at the Fiat Powertrain Technologies factory and at the FCA's Dundee Engine Plant (formerly of Global Engine Alliance's GEMA manufacturing branch), with critical systems manufactured and assembled by Schaeffler Group.

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Wikipedia