To the editor: After reading the recent article on reusable oil filters (The oil filter comes clean Issue 132, Sept./Oct. 2003), I checked with one of the major diesel-engine manufacturers regarding the use of such filters and the possible effect on an engine’s warranty. Yanmar confirmed to me that its warranty requires use of its own oil filters. In my opinion, Yanmar’s position is not unreasonable. The company has tested its engines using its own disposable oil filter and warrants the engine on the basis of those tests. Since it has not tested other filters, Yanmar has no basis on which to approve use of alternative filters. This same pattern has long held in the aircraft industry, and I believe to a large extent in the auto industry. It has nothing to do with the efficiency of the alternative filter, only with the liability assumed by the engine manufacturer.
Contributing Editor Chuck Husick lives in Florida.
