I was relieved that I didn't just go ahead and throw in the spare 5W-30 oil ... where oil is so thick that it affects engine efficiency. Correct Oil Weight Is Dependent On The Diesel Engine ...

When it comes to heavy-duty diesel engine oils ... 15W-40 to 10W-30 can often bring additional benefits such as reduced warm-up times and less wear at startup due to better oil flow and ...

Ford recommends Motorcraft 10W-30 Super Duty diesel motor oil. If the ambient temperature reaches -22.0°F or below, Ford recommends Motorcraft 0W-40 diesel oil. For severe duty uses, the best oil ...