A 5.9L engine's oil capacity isn't a single number. It varies depending on the *specific* make, model, and year of the vehicle. The owner's manual is the only reliable source for the exact oil capacity for your particular 5.9L engine.
While some 5.9L engines might hold around 6-7 quarts, others could need more or less. Using the wrong amount can damage your engine. Always consult your owner's manual.
