High Capacity Fuel Tanks

The standard rear factory fuel tank on the 1966–1977 Ford Bronco holds approximately 13 gallons, which gives a limited cruising range, a common complaint among owners. The auxiliary tank located under the driver's seat offered a capacity of approximately 8 gallons. Tom's Offroad offers high-capacity rear replacement fuel tanks that hold 23 gallons, significantly improving range for trail runs and long-distance driving without requiring a second tank setup.

Yes, replacing the factory rear 13 gallon tank with a high-capacity unit is one of the most practical upgrades for an early Bronco. Extended tanks from Tom's Offroad are designed to fit within the factory skid plate and frame dimensions while maximizing fuel capacity. Most bolt-in replacement tanks use the stock sending unit location for a clean, OEM-style installation.

High-capacity fuel tanks for the 1966–1977 early Bronco are typically available in the 23 gallon size. Larger tanks may require slight modifications to the skid plate or floor clearance. Tom's Offroad offers the 23 gallon version that will fit perfectly in your Bronco.

Replacing the early Bronco fuel tank involves draining the old tank, disconnecting the fuel lines and sending unit wiring, removing the skid plate, and lowering the tank out of the chassis. Installation is the reverse process. Always use new fuel line fittings and inspect the sending unit float before reinstalling. Work in a well-ventilated area away from ignition sources.

The basic fuel tank design on the early Bronco remained fairly consistent throughout the 1966–1976 production run, though minor changes in the sending unit and filler neck occurred across years. In 1977, the rear tank was changed from steel to plastic, as well as the overall design, and the skid plate was designed differently as well. All years share the same limited 13 gallon capacity issue, which is why the high-capacity replacement tank is one of the most universally recommended upgrades for early Bronco owners.