Power Stroke Diesel? More Like Torque Stroke Diesel
The headline news for the fifth-generation Super Duty is the addition of a fourth engine at the top of the lineup, the high-output Power Stroke 6.7-liter turbodiesel V-8. With 500 hp and 1,200 lb-ft of torque, it adds 25 hp and 150 lb-ft over the standard-output Power Stroke that shares most of the same hardware. To make the extra grunt, Ford engineers turned up the boost, dropped the compression ratio, fit stainless steel exhaust headers, and swapped in a cooled turbo housing to keep the aluminum compressor wheel from melting down and becoming part of the intake charge.
Multiplied through first gear and the shorter 3.55:1 final drive, the diesel's grunt balloons to more than 20,000 lb-ft at the wheels—and that's before shifting the four-wheel-drive transfer case into low range. To protect the transmission and driveline, some competitors limit the torque of their beefy diesel engines in lower gears. Ford brags that its new engine never holds back, but there's a big, fat asterisk on that claim: The traction control is always at the ready to cut torque when the tires start slipping.