{"product_id":"a-premium-stretch-fit-serpentine-belt-31-73-in-4-rib-k-section-for-subaru-2-5l-ac","title":"A-Premium Stretch-Fit Serpentine Belt 31.73 in — 4-Rib K-Section for Subaru 2.5L AC","description":"\u003cp\u003e\u003cstrong\u003eThe A-Premium Stretch Fit Air Conditioning Serpentine Belt is a 31.73-inch, 4-rib EPDM drive belt engineered to replace the air conditioning compressor belt on compatible Subaru 2.5L H4 engines.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eThis stretch-fit serpentine belt is designed for a precise fit in specific Subaru models and trims, offering EPDM construction and polyester cord reinforcement for long-lasting durability. Because it’s a stretch-fit style, the belt measures shorter at rest and requires a tensioning tool for installation; once fitted it self-tensions for consistent operation. The belt’s K-section 4-rib profile matches factory routing for the air conditioning compressor on select Forester, Impreza, Outback, WRX, and WRX STI vehicles with 2.5L H4 engines.\u003c\/p\u003e\n\n\u003ch3\u003eWhich vehicles and engine locations does this belt fit?\u003c\/h3\u003e\n\u003cp\u003eThis belt fits many Subaru vehicles equipped with 2.5L H4 engines where an A\/C compressor belt is specified. Confirm vehicle year, engine code, and VIN details to ensure compatibility before ordering.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eSubaru Forester 2009–2011 H4 2.5L; Forester 2012–2013 H4 2.5L (Turbo)\u003c\/li\u003e\n  \u003cli\u003eImpreza 2008–2014 H4 2.5L; Outback 2008–2011 H4 2.5L (VIN 4th digit G)\u003c\/li\u003e\n  \u003cli\u003eWRX 2013–2016 H4 2.5L; WRX STI 2013–2021 H4 2.5L\u003c\/li\u003e\n  \u003cli\u003eDesigned specifically as the air conditioning compressor drive belt (gasoline engines)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow is the belt constructed and what are the key measurements?\u003c\/h3\u003e\n\u003cp\u003eThis A-Premium belt uses EPDM rubber for improved resistance to heat, ozone and wear, combined with polyester cords for tensile strength. It follows the K cross-section standard and provides a 4-rib profile to match factory pulleys and tensioning geometry.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eEffective length: 31.73 inches\u003c\/li\u003e\n  \u003cli\u003eOutside circumference: 32.25 inches; top width: 0.56 inches\u003c\/li\u003e\n  \u003cli\u003eRib count: 4; cord material: polyester; belt material: EPDM\u003c\/li\u003e\n  \u003cli\u003eCross-section designation: K (stretch-fit design)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat does 'stretch fit' mean and how do I install it?\u003c\/h3\u003e\n\u003cp\u003eStretch-fit belts are manufactured slightly shorter than their installed operating length and rely on a tensioner tool and the vehicle’s pulley arrangement to stretch into place. After installation the material relaxes and maintains correct tension, removing the need for manual retensioning.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eRequires a dedicated tensioning tool or installer experienced with stretch-fit belts\u003c\/li\u003e\n  \u003cli\u003eAppears shorter when not mounted—do not trim or force onto pulleys\u003c\/li\u003e\n  \u003cli\u003eSelf-tightens once routed and released, providing consistent tension\u003c\/li\u003e\n  \u003cli\u003eInstallation Location: air conditioning compressor (gasoline engines only)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eAre there part numbers and warranty details I should know?\u003c\/h3\u003e\n\u003cp\u003eThis belt carries multiple reference numbers used across Subaru OEM and aftermarket catalogs, making cross-referencing straightforward. A-Premium supports the product with a limited warranty to help protect buyers against manufacturing defects.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eReference numbers include K040317SF, 11718AA080\/081\/082, 23979AA000\u003c\/li\u003e\n  \u003cli\u003eAlso equivalent to part numbers 4PK805 and 4PK805 SF\u003c\/li\u003e\n  \u003cli\u003eOne-year unlimited-mileage guarantee from A-Premium\u003c\/li\u003e\n  \u003cli\u003eSold as a single A\/C compressor serpentine belt for specified vehicles\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for? If you own one of the listed Subaru models with a 2.5L H4 engine and need a reliable replacement for the air conditioning compressor serpentine belt, this A-Premium stretch-fit K-section belt is built to match factory fitment and long-term resistance to heat and corrosion. It’s a suitable option for professional technicians and experienced DIYers who have access to the proper tensioning tool and who want a direct-fit aftermarket alternative backed by a one-year guarantee.\u003c\/p\u003e\n\u003csection class=\"product-faq-snippet\"\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Can I install this belt without a special tool?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: No. Stretch-fit belts require a tensioning tool for proper installation and safe self-tensioning.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Does this belt fit my Subaru WRX STI 2015?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes. The A-Premium belt fits WRX STI models from 2013–2021 with the 2.5L H4 engine for the A\/C compressor.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"A-Premium","offers":[{"title":"Default Title","offer_id":48084897988766,"sku":"B0D9M2TJVD","price":36.48,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0781\/2041\/9486\/files\/a-premium-front-packaging-ac-belt.jpg?v=1785865498","url":"https:\/\/northtrailauto.ca\/products\/a-premium-stretch-fit-serpentine-belt-31-73-in-4-rib-k-section-for-subaru-2-5l-ac","provider":"North Trail Auto","version":"1.0","type":"link"}