Review on Subaru Genuine 15208AA170 Filter Complete by Justin Jeppi

Don't let the size of this filter fool you, yes it is small but the number of pleats and filters beats most others. larger filters. This filter also has two characteristics that make it superior to most other filters. First, it has Subaru's recommended 23 psi bypass pressure. Find aftermarket filters that manufacturers say are compatible with your Subaru. Most have bypass pressures in the 8-11psi range, which is way too low, meaning you're running unfiltered oil through your engine in many situations. Secondly, by placing the bypass system, this filter allows oil to pass through the bottom of the filter rather than the top, meaning the oil is not drawn over the dirty side of the filter before it gets to your engine. A bit pricey but definitely worth it.