There comes a time in every diesel engine’s life cycle when O-rings fail, fittings loosen, and internal parts wear to the point where the powerplant drops a trail of oil puddles wherever you park the ...

Update #1 September-10-2010 02:41 PDT: With apologies to Ford and our readers, we could have tested lower into the RPM range (below 2,000 rpm) on the 2011 Super Duty. Ford's all-new 6R140 six-speed ...

Diesel Conversion Specialist is offering a Cummins kit to repower Ford trucks with 6.4L Power Stroke engines. The kit includes a 5.9L Cummins engine in 12-valve, 24-valve or common rail configuration.

Here are the best engines in 2026 for towing, fuel efficiency, and more.