This is a FWIW posting that might be useful to someone down the road.

I have a small farm and a small fleet of trucks, car, tractors and small engines to maintain. I have had to keep a whole rack of different oils on hand for maintenance. Don't necessarily mind doing that, but the farm is my second job and I like to consolidate things as much as possible. To that end, I wondered if there was one oil I could use that would work well in everything. First, I cracked the books on my equipment and found that, yes, on paper, a 10W30 HDEO (Heavy Duty Engine Oil) dual rated CJ-4/SM oil would work in everything.... except the '05 F-150.

My main worry with the modular was VCT operation but the recent bulletin about using 10W40 in noisy modulars got me to thinking again. The Ford geeks must have tested this to some degree, plus 10W30 and 5W30 are used in some other markets. Plus, I can datalog VCT operation. I also have a real oil pressure gauge and can monitor oil temp. So, I decided to run a test with heavier oil in the 5.4L and see and was ready to dump the oil back out if things didn't work.

So, I datalogged the VCT in various situations, as well as oil pressure and temp, with the 5W20 I had been using. Then I switched to the Motorcraft Super Duty 10W30 diesel oil, which is a dual rated CJ-4/SM and datalogged again. There is no change. You can't tell the printouts apart. I think I can see the VCT reacts a little bit faster with the heavier oil but it's a tiny change and could also be within the margins for error.

Oil pressure is higher. I previously idled at about 28 psi with hot (190 EOT), new 5W20 RP synthetic and right after the change, the truck idled at 33 psi at the same EOT (Engine Oil Temperature). At 2000 rpm cruising, 190-ish EOT it ran 63 psi w/5W20. Now it runs 66. Cold start (about 40F) it will now idle at 72 psi where before it was 64. At 185F EOT and 5000 rpm (yee-ha!) oil pressure is now about 70, but I didn't check that with the 5W20.

The engine is significantly quieter. With only 30K on it, mine was a pretty quiet 5.4L and once I discovered some noise was normal for modulars, I dismissed what noises there were, but it's a dramatic change to the quiet now.

It's early days yet and I'm still averaging, but it appears the oil temps have bumped up a little. More fluid friction due to the heavier oil or that I went from a PAO synthetic to a Gp II+ mineral oil. Makes sense either way. Not enough to worry about but if I had to say now, it would be a 3-5 degrees increase.

Fuel economy has not appeared to drop. In theory, it should have dropped a little. It may have, but between the electronic MPG readouts and my mile/gallons calcs, I ain't seeing it yet, or at least it's outside a margin for error. Again, I'll have to run this long term perhaps to see the change.

Anyway, the bottom line for me is that I think I can safely run a a 10W30 HDEO, dual rated diesel/gas oil in my entire fleet, including the F150. I make no claims that the 10W30 is optimal in a 5.4L, just that it doesn't effect VCT operation and isn't a major hit in the MPG department.

Two oils fit my specs/price criteria, the Motorcraft and Shell Rotella T5 10W30 semi synthetic. Both oils had very good cold temp pumping numbers in their class and fit my price range... and are readily available for me.

 

Remember, thinner fluids gather and release heat faster. The oil is also a coolant. In testing, we've seen the Xw-40 oils yield hot spots in the engines at temps beyond 700F. So it kinda makes Ford recommend of a 40 oil seems rather stupid. Your 10w-30 is also, as I remember, not on the thick end of the Kinematic scale but towards the lower side. Actual viscosity differential is not that great considering the Xw-20 oils are mostly on the thick side. Fuel mileage will not show from tank to tank. Considering you log everything, I'd expect a 1 1/2% drop in fuel mileage across the life of the engine. Only concerns I have for you is winter cold start. Otherwise, your quest for narrowing it down to one oil fits all, seems reasonable.

 

Yep, mine too. It was a considered choice. I chose the best CCV of the oils in the class. In the F150, the issue is also mitigated by the fact that the truck is usually garage started at no less than 40F, regardless of ambient. I can count the days's it's really cold soaked in the winter on my fingers... I can live with it.

Would love it if and when somebody comes out with a reasonably priced 5W30 HDEO. There are a couple in the boutique realm but they are $10/qt or more. Both the "final two" oils are $4 or less/qt.

Here are a few relevant specs:

MC 10W30 HDEO

cSt @ 40C- 80
cSt @ 100C- 12
CCV- 6200 cP @ -30C
HTHS- 3.5 (actual unknown but per API spec for grade)
VI- 146
PP- -49
TBN- 8.4
Flash- 441F

Rotella T5 10W30 (Semi syn, Gp II+/ Gp III)

cSt @ 40C- 78.9
cSt @ 100C- 12
CCV- 6000 @ -25C (D5293)
HTHS- 3.5 (actual unknown but per API specs for grade)
VI- 147
PP- -44F
TBN- 10
Flash- 435F

 

Jim,

Bravo for a great write up. Very educated, well thought out process. Nice to see some deductive reasoning on here for making an oil decision and/or OCI based on facts and not because "my daddy said so" or "I'm not doing that because...(fill in the blank)"

 

I have used Rotella 10w-30 since I bought my 2009 F-150 two years ago. I live in an area where the temperature during the winter averages right around 0* or lower. I have never had a problem starting my 5.4L in the horrible, cold, nasty winter...fires right up! On the days when the wind chill is below -20* I plug in the block heater.