Yes and no. The engine operating temperature is largely dictated by the thermostat. However, oil temp and water jacket temp are not the same. I actually monitor both on my truck, and the difference between the two at operating temperature can range between 11.4°F on the low end to more than 35°F when run hard.
Plus, many engines have an oil cooler. If that is an air/oil cooler, there will be a major difference in effect on the oil from summer to winter in a climate such as the OP's.

In actual practice, even 66% is not very much difference at 210°F. As your chart shows, you're going from 5-1/2 to 9-1/4.
5-1/2 is about the same as diesel fuel at 72°. 9-1/4 is less than 3 in 1 oil (or sewing machine) oil.
However, it is the basis for my first question in this thread - "mileage".
Once a vehicle has what I feel to be enough miles (used to be 50,000, now over 100,000), I move to a higher viscosity, anyway.
All I can say is it has worked for me. I have put over 300,000 miles (each) on 4 different vehicles so far - and my lawnmower is 23 years old...
And, BTW, the mower has never been rebuilt - and doesn't use enough oil in a season to add any. I bush-hog more now, but the mower used to cut about 10 acres a week for the first 12 years of it's life.

 

From what I have read, and I am not sure the source is all that credible as it was not directly from Ford, the 5w20 oil was adopted to basically get oil throughout the engine quicker. The explanation went on to say that as oil gets older it also gets thicker...therefore 5w20 oil would still be able to flow better than a 5w30 oil. The lower viscosity also aided in cold starting lubrication.

Keep in mind that Motorcraft is a synthetic blend oil. If you are planning on changing your oil out more frequently?

My ecoboost calls for 5w30 and that is what I use Motorcraft oil and filter for my truck.

 

My dealer charges about $40 for an oil change an tire rotation. It takes them less than 30 minutes to do the service. I use whatever they put in.

 

I also use Mobile 1 Full Synthetic 5W-20 for my 2014 F150 FX4 5.0 which is what is called for and it is due to tighter tolerances. I also run the Mobile 1 Extended Performance, High Efficiency, High capacity oil filter.

The manual does state you can go 10,000 miles between oil changes but I change it every 7,500 - 8,000 miles which is what a ford tech said he would do if it was his truck and I think that changing it a little early will better serve an expensive engine. JMHO!

 

I live in the same area as the op however during winter months I'm up in northern Ontario near James bay for work we see Temps and weather similar to southern AK. I have a 12 ecoboost and I've heard of guys running shell Rotella T6 5w 40 oil in the ebs I've toyed with the idea of switching myself do to the fact the truck idles a lot when the mercury plumets... what do you guys think?

 

I had my Motorcraft 5w-30 analyzed at Blackstone. After about 7000 miles, they said it was closer to 20w. Either the dealer put in the wrong stuff, or this engine shears the oil pretty hard. I now have 5w-30 Pennzoil Ultra Platinum in it and will do another OA when I get to 7000.

 

I've seen a few factory fills analyzed from the EB and they all come back in the 20wt range. not sure if the factory fill is actually a 20wt or if it is shearing.


Most of your 30wts will shear down to a 20wt by the end of a interval anyway, so I don't think it is any cause for concern, in fact I think it is factored in.


I did an analysis on my expedition after 5,000 miles and the Trop Artic 5w30 (same as the motorcraft) also sheared down to the top end of a 20wt also. and that's without those fancy hair-dryers hanging off the sides of the motor.


I wouldn't worry about it.

 

My vis @ 100C was 7.25...

 

That's in line with what I've seen elsewhere for a factory fill on the ecoboost.
for example:
https://www.ford-trucks.com/forums/1...tory-fill.html


I wouldn't worry about it, even blackstone considered the possibility that ford is using 5w20 as the factory fill.


here's one of Castrol Magnatec 5w30 with about 7,000 miles, which is a syn blend like the motorcraft
Castrol Magnatec 5-30, 7100miles, 13 F150 Ecoboost | Used Oil Analysis - Gasoline | Bob Is The Oil Guy


I don't think shearing is really a huge issue for this motor. at least, not from what I can tell.

 

Well, this has been a long time coming. 5 short years later and I stumbled across this thread that I started all those years and oil changes ago. Hmmm... I totally forgot all about this. Thanks to everyone who wound up posting on this thread. I actually just read the whole thing. So, to bring you up to date, this is what has been happening. Back then the truck was almost new with about 15,000 kms (less than 10,000 miles) on it. Fast forward until now, and it has 170,000 kms, (105,000 miles) on it. So looking at the Canadian version of the owners manual, I can use full synthetic, or a blend, or straight conventional in it, whatever I like. This is what I opted for. Put a good quality of conventional in it, (Penzoil, Quaker State, Valvoline), with a good quality filter, and get it all out of there at about 8000 - 9000 kms. Thats about 5000 - 5500 miles, well below what the truck is telling me for an OCI. I figure that the oil can take going farther than that, but I want to get that oil filter changed around to get a new one on there. I stuck with the 5w20, like the book said to, and so many on here advised to do. I decided on the conventional because there is so much oil in the pan, and it gets changed often enough, that it will continue to do a good job for as long as I'm using it. I started off with full synthetic, but after the first 3-4 changes, I thought it was just too expensive. I've been swapping back and forth between FL500s and Wix 57045. What ever is a better price, I buy a few of them to have on hand. I just ordered a 12 pack of FL500s (to split with my bro-in-law), for what I thought was a good price, adding these to my previous stock. I guess I will be using them for awhile. To date, I've done 14 oil changes on it, and its due for another one, (so I'm going a little long on some of them).

Now that the engine is getting a few miles on it, I again ask the question about swapping over to 5w30 for the summer/all year. If things are wearing a bit in there, it might be a good thought to put something a little fatter in there for the hot summer months of pulling trailers. I've been on Bob the oil guy for a number of years, and went back to this subject there, but I truly can't find much on the subject. On another forum I belong to, others have said that they swapped over to 5w30 full time and have had no problems at all. I think I will probably switch over to 5w30 and see how things are going, not that there will be any noticeable difference. There will only be the thought in my head of thicker oil protecting the loose parts inside.

 

I'm one of those 5W30 full-timers. At the 1st oil change (500 miles) switched to 5W30 conventional (PENNZOIL). Oil changes are at 3,000-,5000 miles with Motorcraft filters.

Currently at 67,000 miles and have done BLACKSTONE oil analysis done at 21,000, 40,000, and 51,000; all indicating no issues. *Original concern was reported oblong cylinder issues.

Have done the same procedure for my 2003 Crown Victoria LX Sport (which also spec'ed 5W20); it currently has 130,000 miles and was last BLACKSTONEed at 104,000 miles, again with no issues indicated. *Origiinal concern was reported timing chain guide wear issues.

And FTR (For The Record) ... Live in the rust-belt (MIchigan) where the temperature extremes can be/are -20°F (winter) and 100+°F (summer).

Having had hundreds of vehicles over the past 50+ years with several, if not most, having clocked well over 100,000 miles, I'm a full believer that a regiment of quality oil and filters is key to engines' longevity and have yet to have an oil related engine failure.
.

 

It's all going to come down to supplying the valve train.
I don't know anything about the modern 5.0 - but, the 5.4 (in all forms) is sensitive to oil viscosity.
And, my understanding, is that as it ages, it becomes more susceptible to oil delivery problems to the valve train.
The galleries simply aren't big enough to start with, and with time, deposits, and wear of the oil pump itself, make it worse.

 

Here is a blurb from another forum that I'm on. This is from a Ford Tech in PA.

" Current SR Master tech here. 5.0 Coyote engines luckily do not have the same widespread problems at the 5.4 triton. Don't get me wrong , the vct systems still have problems, but not nearly as many. Most likely vct/driveability concern is with the timing chain stretching. Rare but does happen with high mileage ex:150000 miles plus. As far as using 5w30 , every ford publication in the world says only use 5w20. As for the real world , when they get out of powertrain warranty (5years-60000 miles) most customers switch to 5w30 with no adverse effects. All in all the 5.0 has been a very reliable engine. The water pumps and coolant hoses/connections leave a bit to be desired though. Hope this helps ".

And here is another from a ex Ford Tech in CA.

" Also an ex Ford Sr. Master here, left Ford in 2013 and worked on and continue to work on 3v 5.4's as side jobs ".
" The secret to long phaser life is mostly oil. DO NOT USE 5/20 OIL, 5/20 was adopted to help meet CAFE requirements and it does nothing to help your engine. It will get you through the warranty period and even the extended warranty period in most cases but if you keep your vehicles use 5/30 and change it regularly as others have said ".
" When I left Ford the Coyotes were just coming out so I don’t have a lot of knowledge about them but I haven’t heard of them having these (5.4L) issues.
That said, I wouldn’t use 5/20 as bar oil in my chainsaw let alone any engine!
I heard the same small passage / thick oil BS many times. Both my Ford vehicles have over 200k and have never seen 5/20 except the factory fill on my F150 which I dumped during the PDI ".

Back to me now - I've been talking with these guys for a bit now, and I think I'll be swapping over to 5w30 this summer for hot weather/trailer towing season. I have a bunch of 5w20 here that will need to be used up, but I think as I go out and get oil, I'll be swapping grades.

 

When I first bought my '10 I researched the oil and used Blackstone labs and came to the same conclusion as above- 5w30 at 5-5.5k miles changes is the way to go. I just carried that over to my '13. Doesn't hurt that the wife's Mazda uses the same, less to remember!

 

I have a 2010 with a 4.6 3 v. I used 5w-20 while it was in the warranty period. then i did some research on the phaser tick with the 4.6 3v and come across TSB stating to use 5w or a 10w-30 for customers concerned with the tick. I switched to Valvoline max life 5w-30 blend and it still ticks, it maybe a little less noticeable, and i have 246,000 mile and counting with no engine issues.