Originally Posted by Red-Stripe
The reduction in overall air mass flowing will be proportionate to the increase in efficiency, since the computer maintains the fuel/air ratio. If the MDS increase your mileage ( if ), then you have consumed less gas and air.
The small technical negative that offsets this regarding an intake/filter is that when in MDS mode the slightly reduced air mass is now required to be drawn in by 4 widely spaced pulses of air mass acceleration/deceleration instead of a closely spaced 8 vacuum event which normally gives a smother slower overall airflow.
So when in MDS mode you magically need less horsepower to maintain a given speed than when all cylinders are firing? That's incredible!