The flap is flipped by the angle of the accelerator pedal. The larger the angle of reversal, the larger the air. COMPATIBILITY VEHICLES: Our Throttle Body Assembly compatible for 2013-2021 for Buick for Encore | 2011-2015 for Chevrolet for Cruze | 2016 for Chevrolet for Cruze Limited | 2012-2020 for Chevrolet for Sonic | 2013-2021 for Chevrolet for Trax.