What oil should I used in a Cummins M-11? The manual states 15-40 API CE/SG or CF4, but according to Dieselnet.com (https://dieselnet.com/tech/lube_classifications.php)
"By 2012, all service categories except CH-4, CI-4 and CJ-4 were obsolete and a new one was under development. A common reason for the obsolescence of the older categories is a lack or facilities and parts to run some of the key engine tests."
I did not see anything in the backward compatibility chart for CE/SG, but CF-4 references CI-4 and CI-4 plus.
Second question, where do you buy your oil and in what size containers? I presume 1 gallon containers are easiest to handle.
Many of us use synthetic oil, sent you a PM,Amsoil is a good one,I use the 21/2 gallon container.
Costco Delo 400 15/40 with the CK rating is what I buy.
I use Delvac super 1300 15/40 in my Cummins and Detroit's.. Wall Mart 12.47 gallon.. Rotella 15/40 used for decades.. both good oil and I've got a million plus miles on different engines with both brands. I believe the super 1300 is called a semi synthetic.. same oil in generator.
Definitely 15W-40. I prefer Valvoline Premium Blue but there are several excellent choices.
15-40 in most any brand is good oil these days
It must be able to meet your engine manufacturer's standards, most do not.
Yes, the new oil designation for all but the newest engines is CK-4. It is backwards compatible with all diesel engines before those with DEF.
I use Rotela T-6 synthetic. in all my diesel engines. Good protection, flows better when cold so its easier for the engine to turn over and to get oil up into engine quicker.
Not all oils are high detergent.
Cummins shop installed Delo 400 LE in our m11
Delo 400 15-40 or Shell Rotella T 15-40. Both meet the proper CK-4 specs.
Sure, there are other good oils, but, both meet your engines mil-specs AND (big AND) are available in most every Walmart and auto parts house in N America.
Delo offers better rebates;
Promotions
Promotions (https://www.chevronpromotions.com/)
Promo excludes Advance, AutoZone, Carquest, Costco, Mendards, NAPA, O'Reilly, Pep Boys, Sams Club or Walmart....pretty much all of the places I shop!
Costco usually matches the promo prices.
Use Tractor Supply here in Texas. They will have it on sale again soon.
Go to Rural King or somewhere else that sells it.
Why do you use 5W-40? Wasn't your engine designed to use 15W-40?
Low viscosity , ie 0 or 5 weight oil are necessary in computer controlled car engines because the computer immediately brings the engine rpm to 1500 rpm or higher. The most common failure is camshaft related. In most car engines the aluminum cylinder head has no bushings, just the aluminum in the head. The camshaft of course is steel. At cooler temperatures the 10-30 oil takes too long to get to the camshaft, resulting in cylinders head damage.
I use 15 40, primarily because ambient temperatures in some areas are high...
Will 0 40 harm your Cummings, I doubt it.
But the manufacture calls for 15-40, so that's probably what a person should use.
Safe Travels,
Dave
Engines are "designed" to be run with oil that meets certain specifications. From there one chooses a viscosity to cover the temperature range that the engine will be operated in. Rotella T6 5W40 might be overkill for engines that are never started in temps below 50F, but the only possible harm in that situation is to a person's wallet due to the higher cost of the oil.
As far as I know the Cummins M11 was designed to operate on 15W-40 and not on 5W-40 oil. That's why it seems better to me to use 15W-40 in it.
Our local high volume Cummins dealer only uses the delo 400 LE 15-40
I live in Chicago.
Most of my travels take me into the northern part of this country. Most months of the year find morning and evening temps. below 50 degrees and much lower.
Most wear on engines and mechanical parts occur when the engine is cold and continues until the engine warms up. With the M11 and its large oil and cooling capacity it takes a lot of time for the engine to reach operating temp.
As the oil heats the viscosity moves up to the 40 weight range same as the 15-40 oil. The synthetic also flows better than "dino" oil at low temps.
The combo of Synthetic and 5w makes me feel better at start up for MY situation.
This is why I chose the 5-40 synthetic.