I'm not a car engineer or a car mechanic, but I feel like a filter that is less restrictive would improve improve mpg. Which is why a new filter that is not clogged up with gunk yields better mpg.
I can sort of buy into the rough idle aspect of deleting the carbon filter, because it takes a while for the ecu to adapt to the new amount of air it is getting. But reducing mpg's? I'd like to hear a complete explanation about how it reduces mpgs when it is removed. Using reverse logic (which is not always correct) wouldn't that mean adding a carbon filter would increase mpgs? They should add four of them to the M3, so that it can get 32 mpgs
I think the bmw guys just don't want their sexy machines being ruined by over oiled panel filters. Note that I said over oiled not oiled. I don't want to take a stance on oiled vs non oiled, but we can all agree that over oiled is bad and that tends to happen when people recharge their filter.
I don't have a euro intake wish I did
I just have the stock air box, with the carbon delete, and a stock filter. When I do decide to "upgrade" I'd probably just get some cyba scoops, and an AFE ProdryS filter. Just my opinion, I'm sure they make an equivalent or better filter that is dry for you
Have fun out there and be safe! Any loss in mpg imo, is gonna come from the car being driven harder because of the new sound.