This results in wide flexibility of intake valve openings for better fuel economy and power with lower emissions. (greencarcongress.com)
You would never push part of the new intake charge through the exhaust valve opening because the cylinder would be under vacuum at the time. (mechanics.stackexchange.com)
To establish the current driving conditions, the system monitors pedal position, throttle valve opening position, vehicle speed, engine speed, and engine vacuum. (hondanews.com)