why use cone in the engine?? This is hot air. I use K&N box filter which improved the airflow and the car is more responsive during daily driving. Nice air-sucking sound too. Otherwise, I think properly oiled...filtration is the same or better as I see no dirt above the filters, my oil is in fact cleaner than with paper (proven via lab. reports on oil I've seen with paper vs. K&N). Sill working on the fuel economy issue...not sure if it improves that....