Original Equipment vs. Aftermarket Oil and Fuel Filters


Original Equipment vs. Aftermarket Oil and Fuel Filters


Is there a difference?


by Steve D’Antonio

All photos copyright Steve D’Antonio






This Ford Lehman engine has cruised for years with regularly scheduled maintenance and aftermarket filters.



An SDMC Marine Systems Blog reader recently posed the following question: Are there any significant differences in the quality of, say, an original equipment (OEM) oil filter and a Fram filter from a department store? One difference is that the former usually sells for twice the price of the latter. While we all know that businesses must make a profit, just how much is “enough” and how much is a “gouge?”



For some older gear, OEM filters may no longer be an option. In some cases, the current modern equivalent may be an improvement on the orginally specified filter.



This is a great question and one, as a marine systems consultant I hear frequently.  Let me begin by saying that, as far as filters and many other “after market” parts are concerned, your rights as a consumer are protected by the Magnuson-Moss Warranty Act of 1975.  While the details of this federal law are lengthy, in short, it says, “no warrantor of a consumer product may condition his written or implied warranty of such product on the consumer’s using, in connection with such product, any article or service (other than article or service provided without charge under the terms of the warranty)…  Deciphered, this means that if an engine manufacturer claims that you must use OEM filters, and oil for that matter, or the warranty is void, they must either provide these products at no charge or they are in violation of this law.  If you suffer a failure within the warranty period and the manufacturer asserts that it’s a result of the filters or oil you’ve used, the onus is on them to prove that this is true and if they do so, then you have a strong case with the manufacturer of the filter or oil, although I’d rather not contemplate what’s involved in filing a claim against Fram or Chevron.



This oil filter has been remotely mounted, greatly improving serviceability. The builder has chosen to stay with the OEM filter.



In my career as a mechanic then as a boat yard manager and now as a systems consultant, I’ve used and continue to recommend after market fuel and oil filters on a regular basis, and rarely have I had issues with these products and on no occasion have they been serious.  The “issues” typically involve the dimensions of the filter itself.  On occasion, the after market filter is physically larger (not a bad thing, larger often means more filter media is inside) than the OEM part.  Other than that, it’s simply never presented a problem.  When the occasional customer comes along and requests that OEM filters be used, along with the increase in cost, I am happy to comply.  However, the difference in price, even for the exact same part depending upon where it’s purchased, can be considerable.  I recently spoke with a client who installed oil filters on a diesel engine that’s no longer in production.  The one remaining dealer sells the appropriate filter for over $100.



This cut-away display version of a high quality fuel filter clearly shows the complexity of its design.  Predictably, this filter costs more than lower quality models.



Having said all that, I do believe there are differences from filter to filter.  I have no problem using after market filters whose reputation is proven.  That is, well-established brand names such as Fram NAPA, Wix (Wix actually manufactures many of NAPA’s Silver and Gold series filters), Fleetguard (which is owned by Cummins Filtration), and Donaldson, considered by some to be the Cadillac of filters, to name a few.  If, as mentioned above, you have a failure and the engine manufacturer is pointing a finger at the filter manufacturer, you have a much better chance of obtaining restitution from a well established manufacturer as opposed to a brand that’s been relabeled for a chain department store.  While this advice is purely anecdotal, I have cut open (there’s a tool for that) many fuel and oil filters to analyze their contents and in doing so I’ve discovered that they are not all created equal.  In many cases, and among other things, higher quality after market filters have more pleats or media than the OEM equivalent.   As most folks know, few engine manufacturers manufacture their own filters; they simply have them made to the proper specifications by a dedicated filter manufacturer.  So, why can’t you purchase the same filter with a different label and get the same results for a fraction of the price?  The answer is, you can, however, you must observe some guidelines.  Just because a filter screws onto the engine’s threaded boss doesn’t mean it’s the right filter.  It must be properly cross referenced.  This information is available in cross reference phone book-like catalogs (and in some cases on line) available from filter manufacturers.  The filter must be capable of providing, obviously, the correct filtration as well as proper flow rate (finer filtration, i.e. smaller micron ratings, while seemingly more desirable often equate to reduced flow) and by-pass valve pressure release (when an oil filter becomes clogged it will allow the oil to bypass the filtration media because dirty oil is better than no oil at all) as well as an anti-drain back capability, if that’s called for in a particular application (horizontal or inverted filters for instance).  In short, don’t fiddle with the specifications; they were created by knowledgeable engineers with good reason.



This new Volvo engine sports its OEM fuel filter.  It’s quality is virtually guaranteed, but is it worth the added cost? When the time comes to change your engine’s filters, you may choose to stay with the factory original or go with a high quality after-market equivalent. 



If it makes you feel better to use OEM brand filters, along with their associate cost difference, go for it, however, the vast majority of engines operate very well with high quality, after market equivalents.  If you want to do your own comparison, purchase a filter ‘can opener’, they cost about $40.


For more information on the services provided by Steve D’Antonio Marine Consulting, Inc. please e mail Steve at info@stevedmarineconsulting.com

or call 804-776-0981