The K&N E-1997 is a round tapered, oiled cotton-gauze replacement element for the 4.6L V8 in the 2008 and 2009 Ford Mustang Bullitt. K&N's washable, reusable High-Flow filters use layered, oiled cotton media designed to improve airflow and capture contaminants. Because the element can be cleaned and re-oiled rather than thrown away, the higher price is easier to justify over a disposable paper filter. The manufacturer backs it with a No-Hassle Lifetime Limited Warranty. It also carries emissions legal in all 50 US states status and will NOT void vehicle warranty, per the manufacturer.
For fitment, the manufacturer lists this filter for the FORD MUSTANG BULLITT V8-4.6L F/I, 2008-2009 application. The element's dimensions are a height of 8.625 in with a 6 in base outside diameter and a 4 in flange inside diameter. Owners searching for a stock-box swap will find it is designed to install easily into your factory air box. The manufacturer's service interval guidance varies: it states cleaning is needed every 75,000 miles under normal highway driving conditions, while another manufacturer page says the filter can last up to 50,000 miles before cleaning is required depending on driving conditions. Confirm the schedule with K&N for your use.
According to the manufacturer, the E-1997 is listed for the 2008 and 2009 Ford Mustang Bullitt with the 4.6L V8 engine. Check the manufacturer's application search before ordering for any other vehicle.
The manufacturer states the filter needs cleaning about every 75,000 miles under normal highway driving, based on 15,000 miles per year. Its product overview also cites up to 50,000 miles depending on driving conditions, so details vary; confirm with the manufacturer for your driving.
The manufacturer rates this as an easy, DIY-level job that requires only a screwdriver and takes about 5-10 minutes. The filter ships pre-oiled and is ready to drop into your factory air box, so no oiling is needed before the first install. Keep the factory airbox clean while you swap the element, and check that the rubber top and flange seat fully before closing the housing.
