Originally Posted by e90AW335i
I think it has to do with surface area and flow rates of the filters
Ok, so the oem stock filter or any other aftermarket drop-in air filter is 90 sq. in. and Shiv says each of his cone filters is 100 sq. in.; so the dual cone intake has > 2x the amt. of surface area for the air to pass through the filters.
Although I'm not sure exactly how much surface area each of the aFe cone filters has, but they look quite large to me and they definitely have a better flow rate than the oem stock filter.