
Spin-On Oil Filter Gaskets: What Installers Should Know
We recently created a Technical Service Bulletin for a specific part number that PGI supplies to a private label brand. The private label customer was previously buying a different filter from a well-known aftermarket filter manufacturer, who produced this particular filter to different specifications than we do. In short, we produce the filter to OEM specifications, and they did not, which led to confusion and a little angst in the bays where vehicles were being serviced. The difference in the two filters was the gasket – Theirs was a common, lathe cut profile, while ours followed OEM specs for a molded, P-Style gasket. Of course, there are key differences in these two types of gaskets and require different best practices for installation.
Gasket Types
Installers could encounter two different types of gaskets on spin-on oil filters. The most common is a flat, lathe-cut style and the less common is the molded style, which could be shaped like the letters P or L. Both gasket styles seal equally as well for the applications which they were designed, but installation best practices are slightly different.

Installing Oil Filter with Lathe Cut Gasket vs. Molded “P Style” Gasket
When installing a spin-on oil filter with lathe cut gasket, the filter should only be hand-tightened ¾-1 turn once the gasket meets the mating surface of the engine. This creates an axial seal as the gasket is compressed between the filter’s baseplate and the engine surface. Installers should NOT take the same approach when installing a filter with a molded gasket. Instead, a molded gasket can be tightened until the baseplate of the filter is touching the surface of the engine. Unlike the case of lathe cut gaskets, there is no danger in doing this with a filter that uses a molded gasket. If installing a filter with a molded gasket and you realize that the filter is touching the surface of the engine, DO NOT back the filter off because this could result in a poor seal and ultimately leak.
When Different Oil Filters Feature Different Gasket Types for the Same Application
Tags: ECOGARD, Lathe Cut, Molded Gasket, oil filters, PGI, Premium Guard , Private Label, Spin-On, Wix
Categories: Aftermarket Insights, Oil Filters, Spin-on Oil Filters, Synthetic Oil FiltersShare this entry