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How big is the fuel tank on a 1977 Ford F100?

The typical fuel tank size for most 1977 Ford F-100 pickups was roughly 23–25 gallons, with some configurations offering a larger 30-gallon extended-range tank and occasional dealer-installed dual-tank setups that could increase total capacity. Exact figures vary by cab/bed configuration and options, so checking the specific truck’s documentation is essential.


Typical tank sizes and options


In the 1970s Ford offered a standard tank size, with an extended-range option and, less commonly, dual-tank setups. Here’s what was commonly found on 1977 F-100 models.



  • Standard fuel tank: about 23–25 gallons (roughly 87–95 liters), depending on the exact configuration and market.

  • Extended-range tank: around 30 gallons (about 114 liters) on some trucks that prioritized highway use or long-bed configurations.

  • Dual-tank configurations: optional on certain configurations; total capacity varies by the number and placement of tanks (often greater than a single-tank setup but not universal).


In practice, most 1977 F-100s shipped with a single ~23–25 gallon tank, and only certain options or dealer-installed kits pushed capacity higher. Confirming the exact figure for a given truck requires checking its build data or sticker.


How to verify the exact tank size on your 1977 F-100


To confirm the precise capacity for a specific vehicle, use these steps. They account for variations by option package, bed length, and drivetrain.



  1. Check the factory documentation that comes with the truck, such as the original build sheet or window sticker, which often lists fuel capacity.

  2. Look for a fuel-capacity label or decal in the glove box, on the fuel-filler door, or under the hood; this label may show the capacity in gallons or liters.

  3. Decode the VIN or consult the Ford truck build database (community-maintained resources like Ford Truck Enthusiasts) to verify which tank option was installed for that VIN.

  4. Inspect the fuel tank(s) themselves: count the number of tanks and note their individual capacities from stamped markings; add them together for total capacity.

  5. Ask the seller or a Ford restoration expert if the truck has an aftermarket or dealer-installed dual-tank setup, which would affect total capacity.


Having the exact data from the build sheet or official sticker is the most reliable way to know the tank size for a specific 1977 F-100.


Notes on regional and option variations


Fuel-tank options varied by market and option bundles. Some trucks configured for long highway use or special service roles could receive larger or multiple tanks; those configurations were not universal and can significantly affect capacity.


Summary


For a 1977 Ford F-100, the standard fuel tank is typically about 23–25 gallons. A larger 30-gallon extended-range option existed for some configurations, and dealer- or aftermarket dual-tank setups could raise total capacity further. Because tank size depended on cab/bed, engine, and specific options, always verify with the vehicle’s build data or labeling to know the exact capacity.

Kevin's Auto

Kevin Bennett

Company Owner

Kevin Bennet is the founder and owner of Kevin's Autos, a leading automotive service provider in Australia. With a deep commitment to customer satisfaction and years of industry expertise, Kevin uses his blog to answer the most common questions posed by his customers. From maintenance tips to troubleshooting advice, Kevin's articles are designed to empower drivers with the knowledge they need to keep their vehicles running smoothly and safely.