Why air filters are outperformed by cold air intake systems?
Replacement air filters are limited by the size of the original air box. Air intakes do NOT use original air box. Some does not have the air box at all or have it missing most of its walls. So this allows for larger and more exposed filters, which means more airflow and more HP. Also, air intakes use polished and carefully shaped air hoses that reduce turbulence which in turn reduces air flow resistance. Even though filter material may be the same, larger filter sizes and better hoses result in better performance. If you want to achieve 20+ HP performance gains, look into complete air intake system rather than a filter replacement.
