Best part is, this isn't even a diesel. It's got a Hellcat engine. For heavy vehicles you'd want diesel to get good torque and fuel economy. That's why cargo vehicles are almost all diesel powered.

Even if the refineries kept going in the apocalypse, I'm fairly sure places that distribute fuel would be few and far between. This person would have to refuel a LOT... Might not even make it to the next place with fuel.