Which Air Filter is Best? Fram, K&N, Wix, Purolator, AC Delco Showdown

Project Farm tests Fram Extra Guard, K&N Performance, Purolator, Wix, AC Delco, and EP Auto automotive air filters.

Performance testing includes:

• filtering particles 5 microns and larger,
• filtering particles 1-5 microns,
• new filter static pressure and airflow speed,
• used filter static pressure and airflow speed, and
• vehicle 0-60 performance with each brand…

Performance Choice: K&N Filters

If it’s all about performance, or you’re heading to the track for the weekend, the K&N Performance filters are definitely the choice to make.

Non-Performance Choices: Purolator, Wix

For daily drivers and other non-performance applications, Purolator and Wix filters really outperformed the other brands in a big way, showing that while they do cost a little bit more, they’re probably well worth the money.