Is a manual diesel truck better than an automatic?

A manual diesel truck is not automatically better; it is better for some buyers. Manuals can be simpler, engaging, and desirable in older trucks, but condition matters. Check clutch condition, synchros, gear noise, pedal feel, leaks, flywheel history, and whether the truck has been tuned beyond what the clutch can handle. Automatics can tow very well when serviced and kept cool, but a neglected automatic can be expensive. Choose based on how you drive, traffic, towing needs, parts availability, and the specific truck. A healthy automatic is better than a worn manual, and a clean manual is better than an abused automatic.