Q: How long have these air filters been around? A: K&N, Challenger's media supplier, has supplied air filters for race cars and other high performace engines for over 35 years. Q: Do I need to modify my aircraft to install the air filter? A: No. The filters are a direct replacement to your OEM filter. Q: Are your filters FAA approved? A: Yes. The filters are FAA-PMA approved and STC'd which requires a 337 at initial installation. Q: Will I save money on gas? A: Yes. Pilots report a .3 to .5 gallon per hour savings. At 100 hours that is a savings of up to 50 gallons of fuel. Q: How many times can I reclean the air filter? A: Filters can be cleaned up to 25 times or 2500 hours. Q: How do I know when to clean the air filter? A: Filter must be cleaned every calendar year, 100 hours or sooner in dusty conditions. Q: Can an engine get too much air flow? A: No. An engine can only take a fixed volume of air depending on it's size. The more restriction in the air intake system, the greater potential for power loss. Q: Will I see an increase in horsepower? A: Yes. A typical 2-4 percent increase, depending on the current amount of air restriction in the air intake system. Q: What about the AD for paper filters? A: Challenger filters are not subject to the paper filter AD. If you have further questions about Challenger air filters, please call Product Support at 1-937-387-6500.