Rumors that Ford has been pursuing the development of a diesel-powered F-150 are starting to look pretty conclusive from the evidence offered in this video. Spy photog Brian Williams captured this footage of an F-150 Supercab prototype roaming the streets of Oakwood, Michigan, clad with some camo applied to the rear fenders and sounding rather convincing that it may be powered by a motor of the oil-burning variety.

Speculation centers around two different power plants. The first is a 3.0-liter turbocharged V6 making 250 horsepower and 443 pound-feet of torque, sourced from Jaguar-Land Rover, which is currently being used in the Range Rover and Range Rover Sport Td6. The other strong contender is the 3.2-liter turbocharged inline five cylinder Powerstroke already in production in Ford’s Transit van line, which currently produces 185 horsepower and 350 pound-feet of torque.

One thing most can agree on is the gearbox that this mystery motor is likely hooked up to – Ford’s newly developed 10-speed automatic. This would certainly be a strong candidate for the job – with that many cogs to choose from, it would be much easier to tune the transmission to stay in the meatiest parts of the motor’s power band than it would with Ford’s current six-speed slushbox.

The diesel Ford F-150 would join the ranks of the Ram 1500 EcoDiesel, as well as the optional Cummins power plant offered on the new Nissan Titan XD, and GM’s Duramax that is offered on the GMC Canyon and Chevrolet Colorado pickups. Stay tuned for more details as we have them.