Plastic speeds oil change.

A revolution is taking place inside today’s diesel engines, and it is forcing engineers to rethink critical components on the outside, including the humble oil filter.

Suppliers for decades have built filters out of a steel can that surrounds an element. They are simple, but the threads have a tendency to strip out, potentially damaging the engine. They also are heavy, clumsy, and slippery, making them difficult to remove. The casings dent easily and are susceptible to corrosion.

Researchers working for Fleetguard Inc. in Nashville, Tenn., held focus groups with mechanics over the past two years and kept hearing the same complaint, that oil filters were a pain to replace.


The Cummins Inc. subsidiary invested millions of dollars in a project to reinvent the traditional oil filter and came up with a fiber-reinforced composite housing that weighs half as much as steel. It is crushable, burnable and recyclable. As new engines adapt to emission challenges, “we are echoing that through our filtration technology,” says Pamela L. Carter, president of Fleetguard.

Such new materials hold the promise of increased productivity. Installing filters, however, is a hands-on job that still requires a mechanic's touch. Over-tightening an engine filter could damage the element. And leaving it too loose could cause leaks.

Fleetguard’s injection-molding process cuts the supplier’s costs and allows designers to shape the can’s surface ergonomically. Ribs around the outside give mechanics a firm grip, while a flat bottom keeps them from spilling oil on the shop floor.

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  • The company also received a patent for a recessed lug that helps users remove stubborn filters. In goes a 1/2-in. socket wrench, and the filter unscrews easily. The lug is one-directional, which keeps an inexperienced mechanic from over-tightening the filter.

    If successful, the new design will replace the supplier’s existing oil and fuel filters and will come at no extra cost. The firm plans to manufacture six million units this year.

    It may seem like a small step, but the advent of composite filters is another way that diesel engine makers are fighting to keep their share. The lowly filter, as with clean diesel engines, is “being put to the test,” says Carter.