Fleetguard has been around since the 1930's I think. The only filters that clean oil are bypass filters. Fleetguard has bypass filters, full flow filters and combination bypass and full flow filters. Their best bypass filter element uses shredded newspapers and wood chips inside a perforated metal cartridge for use in a Luberfiner housing. The problem with using a bypass filter inside a full flow is it has to be so small it reaches its capacity too soon. It is best to use two seperate filters. The following might be of interest:
Title: Don't Bypass Bypass Filters
Author: Gelinas, Tom
Journal: Fleet Equipment Vol: 14 Iss: 7 Date: Jul 1988 pp. 39-41
Abstract:
According to some estimates, 60% of the potential causes of engine wear and failure can be eliminated by a well-designed and properly applied filtration system. Cummins Engine Co. recommends that both a bypass filter and a full-flow filter be used. A bypass filter shunts 10% of the total oil pump output through a filter and then back to the sump, bypassing the engine. Because this filter has high-pressure differential and low flow rate, it can filter out fine particles in the 5-micron range. In contrast, a full-flow filter has a low-pressure differential and filters out only large particles in the 40 micron to 60 micron range. However, the full-flow filter is located so that all of the oil must flow through it before reaching the bearings. The combination of these 2 filter types gives double protection against wear. Studies at the Cummins Technical Center indicate that wear can be reduced up to 91% by using a bypass filter in combination with a full-flow filter.
Ralph
