Test drive: Ford F650, 6.8-liter Ford Triton, V10 gasoline engine The claim to Ford’s Medium-duty fame has always been its hard-working dependability and durability. For 2016, the F650 sports a second-generation 6.7-liter Power Stroke V8 diesel engine; that’s no surprise. What may come as a surprise is the growing popularity of the gas engine option. A 6.8-liter V10 gas engine is now available for both the F650 and F750. Fleet Equipment Editor Jason Morgan had the chance to get behind the wheel and put the gas engine’s pedal to the metal in this episode of On the Road.