•  The variable swirl system functions to lower emissions at cold-engine start.

•  At cold-engine start, the variable swirl system increases intake airflow speed by closing the shutter valve and narrowing the intake passage. As a result, the air-fuel mixture quality from the injector is improved. Additionally, the creation of a powerful air swirl in the combustion chamber promotes the atomization of the air-fuel mixture. Due to this, exhaust emission efficiency is improved.

•  For the variable swirl control, refer to CONTROL SYSTEM, Variable Swirl Control.