* Terrain: Hills and mountains dramatically reduce fuel economy. Flat land is much more efficient.
* Speed: Higher speeds require significantly more fuel. Maintaining a lower, consistent speed will improve mileage.
* Driving Style: Aggressive acceleration and braking waste fuel. Smooth, steady driving is key.
* Headwind/Tailwind: Wind resistance significantly impacts fuel consumption.
* Vehicle Condition: Proper tire inflation, regular maintenance, and aerodynamic accessories all play a role.
* Specific Vehicle: The overall weight of the vehicle (truck itself) influences fuel economy. A heavier truck will use more fuel.
With a 12,000 lb load, expect extremely poor gas mileage. You're likely looking at 3-5 MPG or possibly even less. It's not uncommon to see single-digit MPG figures in these situations.
To get a better idea, you might look for real-world reports from owners of similar vehicles towing comparable weights in similar conditions (e.g., forums or online communities). However, even these reports will vary considerably.
