An environmentally friendly acid neutralizing filter cartridge for mounting into a chamber of a cartridge mounting body for neutralizing acid in engine oil in an oil circulation circuit of an engine. The environmentally friendly acid neutralizing filter cartridge comprises a support housing comprising substantially no metal parts such that the environmentally friendly acid neutralizing filter cartridge can be readily incinerated. The support housing comprises at least one inlet port and at least one outlet port. A bed of acid neutralizing particles is contained in the support housing between the inlet port and the outlet port. Means is provided for preventing acid neutralizing particles from flowing through the at least one outlet port. An annular seal is arranged externally on the support housing and separates the at least one inlet port and the at least one outlet port to prevent oil from short circuiting the bed of acid neutralizing particles.