Rumor: 10w30 oil only, for 6.0?

[DieselViking]

I was reading through some old threads on TheDieselStop.com just now and read a thread saying that according to a bulletin by Ford to all dealers, the only approved viscosity rating for the 6.0 is 10w30, unless towing above 90 degrees, ??? No 15w40, and no 5w40 recommended. Can this be true? The thread was from late '04, long time ago I know, but I was searching for info on a non-oil related topic. Techs chime in? What have you all heard? I've never even seen 10w30 diesel oil anywhere? I been using good old 15w40 like everyone else I thought.

[sldghamr]

i don't know about the 6.0's since i have a 7.3. i have been running 15/40 Chevron Delo for the past 100k miles. not a lick of trouble.............. yet.

[vitalidle]

I don't think its true. As far as I know 15w-40 for summer months and you can use the 10w-30 for cold temps.

[DieselViking]

Did some more reading about this and I call BS. You'd think 4 years later everyone would know about this. I had an oil change at the dealer 3 months after I bought my truck back in '06 and as far as I know they used 15w40. Must be some bad info. I have heard of guys using 10w30 in winter, but where do you get the stuff? Do they only sell 10w30 diesel oil up north/out west? I'm sure Ford would have a bulletin out about this if it were true.

[cebulmer1]

Ill stick with Rotella 5w-40 synthetic

[mschn99]

ford reccomends 15-40 for summer months....and 10-30 for winter months only in cold climates......for all three DI diesel motors...

[AJF]

Its bad info I went to the diesel clinc at woodhouse (a dealer) a couple months back and it says in their handout that 15W-40 warmer months and 10w-30 for colder months. Last oil change was at a Ford dealer and I watched them put 10w-30 in. So a little miss information.

[DieselViking]

Right on. I've been running 15w40 up to now, but I'm gonna give Rotella 5w40 synthetic a shot for the rest of the winter, and see how the truck runs on that.

[vitalidle]

This is my second winter on the 5w-40 and it made a huge difference for me I have almost 5000 miles with 1500 of that towing and its just starting to get dirty.

[AJF]

Originally Posted by vitalidle

This is my second winter on the 5w-40 and it made a huge difference for me I have almost 5000 miles with 1500 of that towing and its just starting to get dirty.

Are you running synthetic?