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Daryl, Shop Owner, Master Mechanic
Category: Ford
Satisfied Customers: 12549
Experience:  28 years experience, Master Mechanic
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what is the best oil viscosity to use in my 2005 6.0 powerstroke

Customer Question

what is the best oil viscosity to use in my 2005 6.0 powerstroke ? I was told that unless i was pulling a frieght train across the sahra i should use only 10w30 vis. i tow a 41' fifth wheel. my gross weight is a little over 24,000 lbs. I live in the northwest with alot of long 6% grades.
Submitted: 7 years ago.
Category: Ford
Expert:  Daryl replied 7 years ago.
15W40 is the only oil that I know is recommended for this engine so that is what I would use.
Customer: replied 7 years ago.
i just talked to a ford tech today and he said that because of some issues with early 6.0 some techs were recommending i still dont know which way to go.
Expert:  John Crouch replied 7 years ago.
I have been working on Ford diesels since the day of the early 6.9's. We have allways used motorcraft 15-40 oil in them. The only time I recomend using the 10-30 oil is in colder weather for a little better cold starting drivability issues. Never seen any thing inside of one of these motors that has been caused from using the 15-w-40 oils either. The most important thing is to make sure that the oil is rated for diesel engine service and has the proper additives in it. the motorcraft oil does.
Expert:  Daryl replied 7 years ago.


I would stick with 15W40, see pic below especially the part about towing.




6.0 oil grade guide