{"product_id":"amsoil-oil-filter-asf-25","title":"AMSOIL Oil Filter ASF-25 | 13\/16-16 Spin-On","description":"\u003ch2\u003eAMSOIL Oil Filter ASF-25 — 13\/16-16 Spin-On\u003c\/h2\u003e\n\n\u003ctable\u003e\n  \u003ctr\u003e\n\u003cth\u003ePart Number\u003c\/th\u003e\n\u003ctd\u003eASF-25 (also listed as ASF25)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eBrand\u003c\/th\u003e\n\u003ctd\u003eAMSOIL\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eOfficial Product Type\u003c\/th\u003e\n\u003ctd\u003eFull-Flow Spin-On Engine Oil Filter\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eCurrent AMSOIL Cross-Reference\u003c\/th\u003e\n\u003ctd\u003eEaO25\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eThread Size\u003c\/th\u003e\n\u003ctd\u003e13\/16\"-16\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eFilter Height (approx.)\u003c\/th\u003e\n\u003ctd\u003e3.82 in. \/ 97 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eOutside Diameter (approx.)\u003c\/th\u003e\n\u003ctd\u003e3.66 in. \/ 93 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eNominal Filtration Rating\u003c\/th\u003e\n\u003ctd\u003e21 microns\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eSystem\u003c\/th\u003e\n\u003ctd\u003eEngine Lubrication — Full-Flow Oil Filtration\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eFilter Format\u003c\/th\u003e\n\u003ctd\u003eShort GM spin-on\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003ctr\u003e\n\u003cth\u003eStatus Note\u003c\/th\u003e\n\u003ctd\u003eASF-25 is a legacy AMSOIL number; current catalog equivalent is EaO25\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\n\u003ch3\u003eOverview\u003c\/h3\u003e\n\u003cp\u003eThe AMSOIL ASF-25 is a legacy full-flow spin-on engine oil filter in the short GM filter family, using the common \u003cstrong\u003e13\/16\"-16 mounting thread\u003c\/strong\u003e. It removes abrasive contaminants from circulating engine oil while maintaining the flow required to protect bearings, journals, and other lubricated components. ASF-25 is the older AMSOIL number for the filter now catalogued as EaO25, and it cross-references to WIX 51069, Sierra 18-7824, and several well-known MerCruiser and Volvo Penta numbers. Always confirm the existing filter number, thread, and gasket dimensions against your engine before ordering.\u003c\/p\u003e\n\n\u003ch3\u003eCompatible Applications\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eGM-based MerCruiser sterndrive and inboard gasoline engines (see cross-reference numbers below)\u003c\/li\u003e\n  \u003cli\u003eVolvo Penta GM-based gasoline inboard and sterndrive engines\u003c\/li\u003e\n  \u003cli\u003eOMC sterndrive and inboard gasoline engines\u003c\/li\u003e\n  \u003cli\u003eCrusader and Pleasurecraft Marine (PCM) GM-based engines\u003c\/li\u003e\n  \u003cli\u003eChris-Craft and Marine Power GM-based inboard applications\u003c\/li\u003e\n  \u003cli\u003eCompatible older GM gasoline automotive and industrial engines with 13\/16\"-16 filter thread\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eConfirm engine model, serial number, filter location, and existing filter number before ordering\u003c\/strong\u003e — many GM-family engines use different filter formats depending on year, marinizer, and filter-head configuration\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eImportant — V6 marine engines:\u003c\/strong\u003e Several MerCruiser V6 engines use a filter mounted directly on the engine block rather than on a remote filter head. These applications may require a different filter. Confirm the existing filter number for V6 installations before ordering.\u003c\/p\u003e\n\n\u003ch3\u003eDimensions\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eThread: 13\/16\"-16\u003c\/li\u003e\n  \u003cli\u003eHeight: approx. 3.82 in. \/ 97 mm\u003c\/li\u003e\n  \u003cli\u003eOutside diameter: approx. 3.66 in. \/ 93 mm\u003c\/li\u003e\n  \u003cli\u003eNominal filtration: 21 microns\u003c\/li\u003e\n  \u003cli\u003eFlow capacity: approx. 9–11 GPM\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eCross-Reference \/ Alternate Part Numbers\u003c\/h3\u003e\n\u003cp\u003eThe following numbers are associated with the ASF-25 \/ EaO25 filter family:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eAMSOIL:\u003c\/strong\u003e ASF-25, ASF25, EaO25\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWIX:\u003c\/strong\u003e 51069, 51046\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eNAPA Gold:\u003c\/strong\u003e 1069, 1046\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBaldwin:\u003c\/strong\u003e B27\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDonaldson:\u003c\/strong\u003e P550025\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFleetguard:\u003c\/strong\u003e LF651\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFRAM:\u003c\/strong\u003e PH30\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eACDelco:\u003c\/strong\u003e PF25\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSierra:\u003c\/strong\u003e 18-7824\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMerCruiser:\u003c\/strong\u003e 32716, 32717, 35-802885Q, 54111, 866340Q02\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eVolvo Penta:\u003c\/strong\u003e 835440, 835440-9, 3850559\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eOMC:\u003c\/strong\u003e 173232, 502901, 502902\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCrusader:\u003c\/strong\u003e 201104\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePleasurecraft \/ PCM:\u003c\/strong\u003e R077002\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eCross-reference numbers are provided as a fitment aid only. Always confirm the original filter number and full engine application before substituting.\u003c\/p\u003e\n\n\u003ch3\u003eService Interval\u003c\/h3\u003e\n\u003cp\u003eReplace the oil filter at every engine oil change, or at the interval specified by the engine manufacturer. Replace sooner if:\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eFuel, coolant, water, or debris contamination is found in the oil\u003c\/li\u003e\n  \u003cli\u003eThe engine has operated at extended low-speed (trolling) or high-load conditions\u003c\/li\u003e\n  \u003cli\u003eThe engine has been in seasonal storage\u003c\/li\u003e\n  \u003cli\u003eInternal engine repairs have been performed\u003c\/li\u003e\n  \u003cli\u003eAbnormal oil pressure conditions have been observed\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eOld-stock note:\u003c\/strong\u003e Do not install an ASF-25 filter if the canister is rusted or dented, the gasket is hardened or cracked, or the storage history is uncertain.\u003c\/p\u003e\n\n\u003ch3\u003eInstallation Notes\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003eRemove the old filter and confirm its gasket has not remained on the filter head — a double-gasket condition will cause an immediate oil leak\u003c\/li\u003e\n  \u003cli\u003eClean the mounting surface on the filter head\u003c\/li\u003e\n  \u003cli\u003eCompare the new filter’s thread size, gasket diameter, and body length with the removed filter\u003c\/li\u003e\n  \u003cli\u003eLightly coat the new filter’s gasket with clean engine oil before installation\u003c\/li\u003e\n  \u003cli\u003eInstall by hand until the gasket seats, then tighten per the filter manufacturer’s specification — do not overtighten\u003c\/li\u003e\n  \u003cli\u003eRefill the engine with the specified oil grade and quantity\u003c\/li\u003e\n  \u003cli\u003eStart the engine and confirm normal oil pressure immediately\u003c\/li\u003e\n  \u003cli\u003eInspect the filter body and gasket for leaks during the first few minutes of operation\u003c\/li\u003e\n  \u003cli\u003eShut down, allow oil to settle, recheck and correct the oil level\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eRelated Products\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003ca href=\"https:\/\/marisolmarine.com\/products\/sierra-marine-short-gm-oil-filter-18-7824-2\"\u003eSierra Marine Short GM Oil Filter 18-7824-2\u003c\/a\u003e (same filter family, Sierra-branded)\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"https:\/\/marisolmarine.com\/products\/mercury-mercruiser-quicksilver-oil-filter-822626q15\"\u003eMercury MerCruiser Quicksilver Oil Filter 822626Q15\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"https:\/\/marisolmarine.com\/products\/crusader-pcm-oil-filter-with-gasket-r077001\"\u003eCrusader \/ PCM Oil Filter with Gasket R077001\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"https:\/\/marisolmarine.com\/products\/amsoil-15w40-heavy-duty-diesel-marine-oil-ame1gc-378l\"\u003eAMSOIL 15W-40 Heavy-Duty Diesel \u0026amp; Marine Oil AME1GC — 3.78 L\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"https:\/\/marisolmarine.com\/products\/mercury-mercruiser-oil-filter-adaptor-o-ring-25-33756\"\u003eMercury Quicksilver Oil Filter Adaptor O-Ring 25-33756\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"https:\/\/marisolmarine.com\/products\/mercury-mercruiser-16779-remote-oil-filter-adaptor-gasket\"\u003eMercury MerCruiser 16779 Remote Oil Filter Adaptor Gasket — 4.3L V6\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"https:\/\/marisolmarine.com\/products\/volvo-penta-oem-marine-engine-oil-21681794\"\u003eVolvo Penta OEM Marine Engine Oil 21681794\u003c\/a\u003e\u003c\/li\u003e\n  \u003cli\u003e\u003ca href=\"https:\/\/marisolmarine.com\/collections\/oil-filters\"\u003eBrowse All Oil Filters\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eTechnical FAQ\u003c\/h3\u003e\n\u003cdl\u003e\n  \u003cdt\u003eIs ASF-25 still in production?\u003c\/dt\u003e\n  \u003cdd\u003eASF-25 is a legacy AMSOIL part number. The current AMSOIL catalog equivalent is EaO25. If you are ordering a replacement and only have the ASF-25 number, cross-reference to EaO25 or WIX 51069 to confirm the correct current part.\u003c\/dd\u003e\n\n  \u003cdt\u003eHow do I confirm this filter fits my engine?\u003c\/dt\u003e\n  \u003cdd\u003eThe safest method is to check the part number on the existing filter or in your engine’s service manual. The 13\/16\"-16 thread is common to many GM-based engines, but filter height, gasket diameter, and valve configuration can differ. Confirming the existing OEM filter number (MerCruiser, Volvo Penta, OMC, etc.) against the cross-reference list above is more reliable than matching by thread alone.\u003c\/dd\u003e\n\n  \u003cdt\u003eCan I use ASF-25 on my MerCruiser V6 4.3L?\u003c\/dt\u003e\n  \u003cdd\u003eThe 4.3L V6 MerCruiser uses different filter configurations depending on year and whether the filter is remote-mounted or block-mounted. Check the filter number currently on your engine — if it matches one of the MerCruiser cross-references listed above (32716, 32717, 35-802885Q, 866340Q02), ASF-25 \/ EaO25 is in the correct family. If your V6 uses a different filter number, do not assume fitment from the V8 cross-reference.\u003c\/dd\u003e\n\n  \u003cdt\u003eWhat is the difference between ASF-25 and EaO25?\u003c\/dt\u003e\n  \u003cdd\u003eThey are the same filter family — ASF-25 is the older AMSOIL part number; EaO25 is the current designation. The physical filter and specifications are equivalent. If you have a stock of ASF-25 filters, they are the correct product for the same applications.\u003c\/dd\u003e\n\n  \u003cdt\u003eCan I use Sierra 18-7824 instead?\u003c\/dt\u003e\n  \u003cdd\u003eYes — the \u003ca href=\"https:\/\/marisolmarine.com\/products\/sierra-marine-short-gm-oil-filter-18-7824-2\"\u003eSierra 18-7824\u003c\/a\u003e is in the same filter family and is a widely used marine equivalent. Confirm the existing filter dimensions as above before substituting any brand.\u003c\/dd\u003e\n\u003c\/dl\u003e\n\n\u003chr\u003e\n\u003ch3\u003eParts Desk Insights\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eBest use case:\u003c\/strong\u003e The ASF-25 is the right filter for customers maintaining older GM-based marine gasoline engines — MerCruiser 350 \/ 454 inboards and sterndrives, Volvo Penta 5.0 and 5.7L GL\/GS, OMC inboards, and Crusader \/ PCM applications where this short GM filter format is specified. At $17.64 it is an accessible, quality option for customers who know their existing filter number and just need a reliable stocking cross-reference. The legacy ASF-25 number comes up frequently with older AMSOIL stockists and customers carrying over historical service records.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eCommon customer questions:\u003c\/strong\u003e The most frequent issue is customers using the 13\/16\"-16 thread to justify fitment without checking body length or gasket diameter — particularly on V6 MerCruiser applications where the filter may be block-mounted rather than remote-mounted. Always ask for the existing filter number if the customer is unsure. The second common question is whether ASF-25 and EaO25 are the same thing — they are, but customers with historical records or older AMSOIL invoices often have only the ASF-25 number.\u003c\/p\u003e","brand":"FVW","offers":[{"title":"Default Title","offer_id":43563795087396,"sku":"ASF-25","price":17.64,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0743\/5799\/7604\/files\/images_6e29fc02-34e7-40b2-a64f-7d746e98dd6e.jpg?v=1788757711","url":"https:\/\/marisolmarine.com\/products\/amsoil-oil-filter-asf-25","provider":"Marisol Marine Company","version":"1.0","type":"link"}