Best Automotive Replacement Fuel Tank Caps (2026 Guide)
We selected items by high aggregated user ratings and review volume, confirmed vehicle fitment/specifications, and evaluated build materials and noted functional features
This roundup covers top-rated automotive replacement fuel tank caps and closely related filler caps for diesel and gasoline vehicles, focusing on fit, material, and compatibility. Picks were chosen by aggregated user ratings and review volume, and by verifying vehicle fitment, materials (aluminum, OEM plastics), and notable features like DEF cap combos and magnetic closures
Top Picks
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1
RAM Diesel Fuel Cap + DEF Cap Combo (2013-2018) Easy Grip
Combo pack with a magnetic RAM diesel fuel cap and DEF cap. Keeps dirt and water out of the fill, with a smooth, easy-to-grip DEF cap and durable aluminum construction. Customers note secure magnetic attachment and OEM-like fit
- magnetic retention on metal surfaces
- two-cap combo for fuel and DEF
- rust-resistant aluminum with color anodizing
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2
DOCA Diesel Cap for Dodge Ram 2019-2025
Diesel fuel cap designed for Dodge Ram trucks with capless fuel systems. Provides airtight, dust and water resistance for the fuel system. Customer note: strong fit and build, with mixed feedback on lockability and magnet strength
- Diesel-cap compatibility
- Airtight, dust & water protection
- Heavy-duty construction with good fit
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3
Aluminum Diesel Cap for 2019-2021 Dodge Ram 6.7L
Diesel fuel cap with precise seal to keep dust, water, and debris out. Notable for fit on 2019-2021 Ram diesel models; customer notes strong appearance and secure fit with some difficulty in removal
- precision seal keeps out dust and moisture
- specific fit for 2019-2021 Ram diesel trucks
- alk aluminum construction for durability
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4
Fuel filter housing cap for Ram/Cummins 68065612AA
CNC billet aluminum fuel filter housing cap compatible with 2011-2024 Ram 6.7L and 2010 Dodge Ram diesel engines. Notches for a secure fit and leak prevention; includes cap only. Customer insight notes sturdy build and easy installation, with some concerns about thread scratches and sealing surface durability
- all-metal billet build
- accurate fit for 2011-2024 Ram 6.7L
- leak-prevention design
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5
Cap Assy, Fuel Tank (Toyota OEM)
Fuel tank cap assembly, OEM Toyota quality and vehicle-specific fit. Customers say it snaps in place with easy installation and matches their vehicle, though some report leak concerns in the seal
- genuine OEM part
- vehicle-specific compatibility
- easy snap-in installation
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6
Honda Genuine Fuel Filler Cap 17670-T3W-A01
Genuine OEM fuel filler cap designed for exact fit and durability. Consumers note authentic Honda quality and fit, with some praise for improved gas mileage and easy installation; a few report tether attachment issues
- genuine oem part
- exact fit
- durable
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7
Aluminum DIESEL Cap for 2019-2021 Dodge Ram 6.7L
Diesel fuel cap with airtight, precision fit to protect the fuel system. Made from anodized billet aluminum for durability; fits 2019-2021 Ram diesel trucks. Customer notes it fits well and keeps dust and water out
- diesel-specific fit
- durable aluminum design
- fuel protection from elements
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8
Dodge Ram Diesel Fuel Cap (2019-2025) Aluminum Magnetic Cap
Aluminum diesel fuel cap with built-in magnet and rubber seal. Helps keep dust out and attaches to the body while refueling. Customer notes fit on GMC 1500 diesel models and quality construction
- magnetic fuel cap
- dust-sealing rubber ring
- aluminum alloy cap
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9
GM Genuine Parts locking fuel tank cap with 2 keys
Locking fuel tank cap engineered for a tight seal with a tamper-resistant lock. GM OE specification for fit and reliability; customers note solid functionality and value for money
- lockable design
- GM OE fit
- two keys included
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10
Fuel Filter Housing Cap for GM Duramax 6.6L L5P (2017-2024) billet aluminum
Replaceable billet aluminum fuel filter housing cap for GM Duramax L5P. Stronger than OEM, with drain plug; includes cap and drain plug (O-ring not included)
- Billet aluminum for durability
- Direct replacement part number 134001
- Reinforced housing to resist cracking