Sierra 18-7802 Fuel Filter The Sierra 18-7802 Fuel Filter is interchangeable with the following: Fram P8263, Mercury 35-87946Q4, 35-87946Q3, 35-87946A3, Wix 33398. Use with 18-7113-9 O-Ring. Sierra Fuel Filter Meets or exceeds the original equipment quality Sierra part number: 18-7802 Interchangeable with the following: Fram P8263, Mercury 35-87946Q4, 35-87946Q3, 35-87946A3, Wix 33398