No, Pennzoil conventional or even Pennzoil Platinum (their high-mileage synthetic blend) is
not recommended for a 2000 F250 diesel. Your 2000 F250 likely has a 7.3L Power Stroke diesel engine, which requires a
CJ-4 rated diesel engine oil. Pennzoil's offerings for gasoline engines won't meet the necessary specifications for a diesel engine, especially one as robust and demanding as the 7.3 Power Stroke. Using the incorrect oil can lead to serious engine damage.
You need a diesel-specific oil that meets the CJ-4 specification (or possibly an earlier specification like CH-4 depending on your truck's exact requirements - check your owner's manual). Many brands offer this type of oil, including Shell Rotella, Mobil Delvac, and others. Always consult your owner's manual to verify the exact oil type and viscosity recommended for your vehicle.
