Read the Diesel Manual........

5W-40 Synthetic is HIGHLY Recommended.

I used it all year.

 

There sure is synthetic 10w30 for diesels. Here for example:
AMSOIL OE 10W-30 Synthetic Diesel Oil

 

Page 59 of the 2016 powerstroke diesel supplement specifically calles for 10w-30 API CJ-4 for normal usage

 

Yep.

I only have 10k miles on mine so I've only changed the oil once. $30 per gallon with free shipping on Amazon Prime. I don't care about saving a few bucks when it comes to oil, it seems like good stuff.

Edit: Just noticed your post mentions 10W-40. I used 5W-40.

 

The term "normal" does not cover many applications.......

I tow heavy in the hot summer. that is Not normal......
I run in cold weather....-20°F That is Not normal......
I tow on gravel and dirt roads for many miles, Not normal........

The 5W-40 works well for me..........

 

What Roy said x2.

And the manual says to use an oil based on your climate and they provide a chart for you.

I could care less what dump trucks, OTR trucks, or a cat tractor uses for a comparison of what I should use in my super duty. Those motors are used and assembled differently. Even though I'm sure some oils work well in both applications, I'm interested in what works well in the super duty I have in my garage.

I prefer a synthetic diesel oil. 5w 40 seems to cover most of the operating Temps I see. In Florida I use it for the heat protection and in AK for the cold.

 

Which is the reason Ford saw it fit to include the chart in their supplement......

 

Plus you can get synthetic 5w-40 for just a little more than MC 10w-30 at Wally World.

 

The diesel supplement includes the language "for severe service, use 5-40". From that and other information we may assume that Ford thinks 5-40 is better for your engine, but unnecessarily expensive for "normal service". I appreciate that some have had good UOA data with 10-30, but that does not make the case - it is not a controlled test.

I'm not arguing that you should run synthetic, or that it is necessary for long engine life. But I have yet to see any evidence that it is worse for any reason other than cost. I'd be interested in any well researched paper that concludes 10-30 dino oil is better (in any respect other than cost) compared to a good grade of synthetic. There are numerous well researched papers concluding that synthetic is better.

 

x 3

Sometimes its hard to know exactly what, when and how my truck will be used on a specific day, weekend, season, etc, so why not use an oil that FORD approves/recommends for all conditions and use, 5w-40 does it all for our 6.7.

 

Nobody is arguing against 5-40 syn. I run premium blue extreme in my 6.7 because I fall into severe service. I'm just simply quoting the supplement from Ford. Most people that just pull a boat and Cruse the highway will be fine with 10w30 diesel engine oil. They actually recommend 0w30/0w40 for all temperature ranges.

 

Just was agreeing with the members I quoted above.
Wasn't arguing against against 0-30 cj-4 or 0-40 cj-4 oils.

They are (along with 5-40 cj-4) the only oils approved by Ford for our 6.7 in ALL temps. Good grade of oil imo. Most are full synthetic, but some might be a blend.

0-30 cj-4 or 0-40 cj-4 are not Ford approved for severe duty service, like 5w-40 cj-4 is...?

5w-40 cj-4 is on the shelf at every auto parts store, Walmart, etc... very easy to get for a reasonable cost. And I repeat, its the only oil that Ford approves for all temps and all uses, including severe duty service.

iirr, many 0-30 and 0-40 are arctic grade oils, so they probably/maybe would protect better in that type of climate below -20°F. Also are fine for all climates.

But down here in FL, try to find cj-4 0-30 or 0-40 on the shelf...? I haven't ever seen any. Not even sure what they cost...

Here is what Ford says about severe duty...
http://www.fordservicecontent.com/Fo...US_02_2014.pdf


Engine lubrication for severe service
operation
The following conditions define severe
operation for which engine operation with
SAE 5W-40 API CJ-4 is recommended. Oil
and oil filter change intervals will be
determined by the Intelligent Oil Life
Monitor
™
as noted previously.
•
Frequent or extended idling (over 10
minutes per hour of normal driving)
•
Low-speed operation/stationary use
•
If vehicle is operated in sustained
ambient temperatures below -10°F
(-23°C) or above 100°F (38°C)
•
Frequent low-speed operation,
consistent heavy traffic less than 25
mph (40 km/h)
•
Operating in severe dust conditions
•
Operating the vehicle off road
•
Towing a trailer over 1,000 miles (1,600
km)
•
Sustained, high-speed driving at Gross
Vehicle Weight Rating (maximum
loaded weight for vehicle operation)
•
Use of fuels with sulfur content other
than ultra-low sulfur diesel (ULSD)
•
Use of high-sulfur diesel fuel

 

Here's the end result -
I showed up at my dealer for my oil change and asked the same person I spoke to on the phone, while setting up my appt, why they won't put MC 5w-40 syn in my engine if I requested it and felt the conditions my engine would be exposed to would be outside of the 10w-30 specifications and the environment my engine would be exposed to does fall into the range for MC 5w-40 syn. I asked why Ford would sell an oil that they never, ever would sell to any customer and preferred we cold start our engines with an oil not spec'd to be used in the -20f to -40f temperatures.
The service advisor then told me "Oh, we can put it in IF WE HAVE ANY IN STOCK."
WTF? I explained we already had this conversation (twice) that I would be using my 6.7 in a harsh environment for upwards of the next 60 days.
The dealership then decided they actually could put my requested oil in my 6.7 after all.
Perhaps I need a better dealership for service.

 

Wow, yeah...I would have to agree with you. My local dealer has treated me very well,when I do go there for any work, mostly tech stuff. I use an independent shop for a lot of my mechanical stuff and service,coincidently,my shop guy takes all his alignments, no matter the make,to the same Ford dealer.

 

Dealers push the 10w-30 simply because it will work for 97% of the trucks on the road. One thing Ford has always done is tried to make taking care of your vehicle as simple as possible, no high octane gas required or exotic fluids except for the 5w-50 required in the track-pack cars.

It is extremely difficult to show one oil is better than another, I have chosen to use 10w-30 and UOA data has shown it to be a good decision for me. If one day were to switch to a 5w-40 and run UOA's I simply can't fathom what, if any data point would justify my decision to spend more per OC. My current oil cost approx. $14 per gallon and I am already going until the IOLM says "change oil now", and every UOA has come back "OK for extended use". I have no desire to extend beyond what Ford engineers have decided to be the condemnation point of my oil.

If I were expecting extreme cold for an extended period (-20F & colder) I surely wouldn't be using a 5w-40, I would have some 0w-30/0w-40 on hand ready to go. Any temp above -20F a 10w-30 has worked just fine for me.

I have yet to see in any diesel truck engine where a properly specced synthetic oil protected any better than a properly specced conventional, or made an engine last any longer. The IOLM is programmed for CJ-4 spec oil, no where is it stated if you use synthetic the drain interval can be extended. Cleanliness of the internals/soot handling is achieved with the additive package of the oil. Unless there is a major failure within the cooling system oil temps are well below any oil damaging temp.