Here is what shell has to say on the question of which oil to use in your ford diesel

For the Ford 7.3L and 6.0L Power Stroke Diesels, Shell Rotella T
Synthetic Oil SAE 5W-40 fully meets specification requirements for all
temperature operation. For the new Ford 6.4L Power Stoke engine, API CJ-4
oil is required, and we haven't yet introduced an API CJ-4 version of our
synthetic oil. However, we expect the reformulated synthetic oil for
that spec will be available on the shelves in the next two months, and,
at that time, Shell Rotella T Synthetic Oil SAE 5W-40 will meet the
requirements for the new engine, as well.
So I don't know what ford is telling some of you but shell says it will work.

 

hi just bought a 2003 4x4 f350 four door dually 6.0 ,i live in nova scotia can.temp. here runs from -10 to +30 what type-grade of oil should i be using ?always run irving ido 15-40 in my old 7.3 idi,but know these engine needs something better .

 

Use a good quality and reputable synthetic 5W-40. It appears to give the best results and least problems to most owners as the injectors will love you since they are so sensitive and seems to require the better oils.

 

I thought I read somewhere in this thread that the injectors broke down the lower viscosity 5-40 too fast in the 6.0 and it actually would harm the injectors. Am I wrong?

 

the fist
if you go back in this post you will see the answer I got for shell oil

 

I didn't even see that. All temperature, even hot 100 degree summer weather. Thats good.

 

I have used Shell Rotella 15w40 for years. I buy it in 55 gal drums. Goes in my powerstroke, all my tractors, combine and even my grasshopper mower with the kabota diesel. Great oil. I use the synthetic Rotella in our Jeep Liberty. Also great oil. I am considering switching the Jeep to the conventional due the convenience for me. Hope this helps

 

so rottela syn 5w-40 is good for all temps
what about towing 12,000lbs in 100 degree temps?

 

Can't say first hand. I'm not an oil expert. I believe Ford reccommended sythetic in my 06, but I've been using the 15w40 year round ever since the first oil change. I use this oil in 11 different diesel engines in all temps. I used to pull a gooseneck grain trailer with my 96 7.3 loaded with as much as 400 bushels of corn ( at 56#/bushel do the math) using the 15w40. Ive only used the synthetic in a 2.8 turbo mercedes which is in the liberty

 

ford after taking in for service eith 3500 miles it was way over do must change it be for 200 hrsfore me it means 1800 miles or so a little costly

 

5W-40 synthetic oil will work year-round and will work great.

Synthetic oil runs cleaner than dino oil due to the high-refiing process it goes through. I have run year-round and my oil analysis results come back just as though I had been running dino... so it is protecting just fine.

I like the better high and low temp/heat protecting the 5W-40 offers.

 

Just an update on wether 5W-40 synthetic is OK for all powerstrokes in all weather here's the latest from the Motorcraft website:

http://www.fcsdchemicalsandlubricant...sp?product=SAE 5W-40 Full Synthetic Diesel Motor Oil&category=Motor Oil

<TABLE border=0 cellSpacing=5 cellPadding=0><TBODY><TR><TD>Motorcraft SAE 5W-40 Full Synthetic Diesel Motor Oil is a high-performance light and heavy-duty diesel engine oil designed, engineered, and recommended by Ford Motor Company. It is particularly recommended for use in Ford vehicles equipped with Power Stroke engines as in truck, bus, construction and other heavy-duty diesel engine applications. It meets API Service Category CJ-4, required for use in diesel engines designed to meet 2007 on-highway exhaust emission standards and requiring ultralow sulfur diesel fuel. Do not use in gasoline engines equipped with catalysts.</TD></TR><TR><TD vAlign=top>

</TD><TD>Motorcraft® SAE 5W-40 Full Synthetic Diesel Motor Oil is a high-quality diesel engine oil formulated with synthetic base oils and unique additive technology. It satisfies the warranty requirements of Ford Motor Company as well as most other domestic and import diesel engine manufacturers.</TD></TR><TR><TD vAlign=top>

</TD><TD>Motorcraft® SAE 5W-40 Full Synthetic Diesel Motor Oil is designed for new generation, low emission diesel engines providing excellent soot control, protection against wear, deposits, rust and corrosion, foaming, sludge formation, high temperature oxidation and thickening, as well as protecting exhaust aftertreatment systems such as particulate filters. It also provides excellent performance in older-generation diesel engines operating on high-sulfur fuel.</TD></TR><TR><TD vAlign=top>

</TD><TD>Motorcraft® SAE 5W-40 Full Synthetic Diesel Motor Oil can be used in older engines where the manufacturer recommended API Categories CD, CF-4, CG-4, CH-4, CI-4 and CI-4plus.</TD></TR><TR><TD vAlign=top>

</TD><TD>Motorcraft® SAE 5W-40 Full Synthetic Diesel Motor Oil is recommended for use in Powerstroke® diesel engines over a wide temperature range, from -20°F (-29°C) to over 100°F (38°C).</TD></TR></TBODY></TABLE>

 

If Ford Motorcraft 5w-40 synthetic CJ-4 oil is approved for use in all powerstroke engines, does this mean that any 5w-40 synthetic CJ-4 would be approved for use also? I was looking at Walmart today and the Rotella 5w-40 Synthetic oil is selling for $19. and I was thinking of using it going into the winter. My truck is an 05 6.0L, has used Motorcraft 15w-40 for the last 40k miles would this be a good change or should I stick with the Motorcraft oil???? I tow a 12K fifth wheel and will be going to Florida in the cold weather and returning in April when temps are going up. Is this going to be a problem or not for towing in higher temps?

 

I haven't used it myself but from what I've read Rotella 5w-40 Synthetic is good oil.

 

IF you are towing a lot you will like the Rotella Syn 5w-40. I just switched to it from the Ford oil (non-syn) and the difference is dramatic. Oil temps were lower, sounds quieter, and even though I always poo poo such claims from others, BUT I would swear it has more power. My F-350 never pulled my 5th wheel Toy Hauler better than it did this weekend after switching over just before the trip, AND my Toy Hauler was loaded heavier than ever before.

After this last trip I will never run anything else.