K&N intake air system
Does an K&N air intake system really improve MPG and horsepower.
Forum Discussion
It may increase airflow, initially, but tends to restrict quicker when used in moderate conditions. I have a K&N on a 5.4 V8 and don't notice any significant mileage improvements. The K&N needs scheduled cleaning and reoiling to function correctly.
Since Ford chose to equip the 5.4 V8 in 2003 with an air filter that was prone to flange damage, I chose to use a K&N filter. Since 2005, the Ford filter flange has been redesigned with a reinforced flange material. When/if I replace my K&N filter, I will probably choose the newer Ford paper filter.
Since Ford chose to equip the 5.4 V8 in 2003 with an air filter that was prone to flange damage, I chose to use a K&N filter. Since 2005, the Ford filter flange has been redesigned with a reinforced flange material. When/if I replace my K&N filter, I will probably choose the newer Ford paper filter.
