NAPA

NAPA (National Automotive Parts Association) is a US auto-parts retail cooperative operating over 6,000 independently owned stores, founded in 1925. Its private-label NAPA Gold filter line (oil, engine air, and cabin air filters) is manufactured by WIX Filters, part of the MANN+HUMMEL filtration group; a NAPA Gold part number typically converts to its WIX equivalent by adding a leading "5" digit (e.g., NAPA Gold 1356 = WIX 51356), a widely documented cross-reference in the automotive parts community.

NAPA also sells a Proselect economy filter tier and a Platinum premium tier alongside NAPA Gold. Part-number supersessions are common across the NAPA Gold oil-filter line as automakers change an engine's oil-filter-boss/baseplate design (for example, a shift from an older convex baseplate to a newer flat baseplate with an integrated hex nut); NAPA reissues a superseding part number for the updated design rather than revising the original number in place, so a given NAPA Gold number can be the correct filter for one generation of an engine platform and the wrong one for a later generation.