Is an AMSOIL Bypass Oil Filter Worth It?
A bypass oil filter adds fine-particle filtration alongside the engine’s full-flow filter. Check installation space, kit compatibility, replacement-element costs and manufacturer requirements before buying.
Compare your use, installation requirements and recurring costs before buying.
The short answer
A bypass oil filter can be worthwhile for a high-use diesel truck when supplemental filtration fits your maintenance plan. It is an additional purchase and service item, so compare the complete cost with your goals before ordering.
The bypass filter handles a smaller oil stream through a separate path. It supplements the full-flow filter; it does not replace it.
Who is likely to benefit?
| Your situation | What to consider |
|---|---|
| Frequent towing or high annual mileage | Supplemental filtration may be worth evaluating alongside oil analysis and a documented maintenance plan. |
| Occasional use and low mileage | Installation and recurring filter costs may outweigh the value to you. |
| Limited space or difficult oil connections | Check installation feasibility and labor cost before buying any kit. |
| Looking for automatic extended oil changes | A filter installation does not automatically approve a longer oil-change interval. |
Compare the whole cost
Your budget should include the correct kit, any application-specific adapter, installation labor if needed, the initial oil service and future replacement elements. Oil analysis is another cost if you intend to use it to evaluate oil condition.
Compare these costs with your actual use. A claim of guaranteed savings or engine-life improvement would require evidence for your situation, so we do not promise either.
Find a system for your engine
For supported Cummins applications, BMK34 is one option to research. It is not a universal kit for every diesel. Our Cummins BMK34 guide explains included components and the optional adapter.
What does maintenance involve?
Keep the full-flow filter in service, replace the bypass element according to its application guidance, inspect the plumbing and monitor oil condition. The filter does not remove every reason oil needs changing.
See an installation example
Watch Cummins Bypass Oil Filter Installation on its video page →
Use the video to understand the layout, then follow the current instructions for the exact system you choose.
Learn more in AMSOIL's explanation of bypass filtration.
Common questions
Is a bypass oil filter worth it?
It can suit high-use diesel owners who want supplemental filtration and accept the installation and maintenance costs. Low annual mileage or limited installation space can make it less worthwhile.
Does bypass filtration make oil last forever?
No. Filtration does not prevent every change in oil condition. Follow the applicable maintenance guidance and assess oil condition rather than assuming unlimited use.