Someone Pls Explain Caterpillar Oil Recommendation

[George7941]

Subject vehicle is a 2007 Freightliner M2 with a C7 engine. You can find the engine oil recommendations here
https://caterpillar.scene7.com/is/content/Caterpillar/C10513034

Here are two statements on page 15
"Generally, use the highest oil viscosity that is available to meet the requirement for the temperature at start-up"
"SAE 10w30 is the preferred viscosity grade for the following diesel engines when the ambient temperature is above -18*C (0*F) and below 40*C (104*F)"

The "Lubricant Viscosities for Ambient Temperatures" on the same page lists -9.5*C as the minimum temp for 15W40.

Right now, with typical fall temp min of 5*C and max of 20*C, the first statement would have me choose 15W40 since it meets the requirement for cold starting. In other words, it is advocating "thicker is better". Yet the second statement would have me choose 10W30. Huh?

 

[Garak]

I think there was some posting on it once before here, over this confusing matter. I don't recall what the consensus was, but I'd be tempted to follow the 10w30 recommendation, since it does specifically call it the preferred viscosity grade for your engine in those ambient temperatures. And you know how these manuals can be written. To them, highest oil viscosity might not quite be the same thing that some of us mean. Is a 0w30 HDEO thinner? Yes, at least under certain circumstances, and perhaps most circumstances. A 0w-40 or a 5w-40 are thinner under certain circumstances.

I would say, however, that they bring up the statement about 10w30 being the preferred grade twice on the same page. I think Doug helped us out in the last thread. Maybe he'll notice this one. Of course, other posters have experience in this, as well.

 

[SatinSilver]

Here's a used oil analysis on a Volvo engine that looks very good with a 10w30. May want to check it out:

https://bobistheoilguy.com/forums/ubbthreads.php/topics/3901116/Re:_Delvac_Elite_10W30_21,900_#Post3901116

 

[tinmanSC]

Recommended and allowed are not always the same thing. The recommended oil grade, for all conditions of -18C to 40C is 10w30. What they are saying is when in doubt you can always use 10w30 and not have to worry about changing the oil when the temp changes, that's probably the #1 reason it's the recommended grade. Then they go on to list the allowed oil grades for temps which can be different and can be optimized for the specific temps and conditions (but you'll fall out of that optimized grade when the weather changes). Many automotive manufactures still do this. In the owners manual it will state "Recommended oil: 5w-20." or something, then below it will be a chart showing allowed oil grades by temp. It's no different for Cat. I'd stick with the overall recommended grade (10w30) until you have specific reason to change it.

 

[George7941]

Here is another statement. also on p 15, that muddies the waters.

"If the ambient temperature conditions at engine start-up require the use of multigrade SAE 0W oil, SAE 0W-40 viscosity grade is generally preferred over SAE 0W-30."

So they do prefer the 40 weight at operating temperature over 30 weight but they still recommend 10w30 over 15w40?

January through March, over the past few winters, I have run the engine on Mobil Delvac 1 0W-40 ESP and I plan to do so again this winter.

This engine shears the oil so much (it has the HEUI injection system) that after about 7k km, the engines sets codes about not being able to reach injection pressures and I have to change the oil. This in spite of a 28 litre sump.

 

[userfriendly]

IF the ambient temperature require a 0W engine oil.....

Does you ambient require a 0W at start up?

Does your manual mention other XW40 grades than 0W40 as an option in cold weather?


Truckers!.....You can't live with them and can't live without them.

 

[OneEyeJack]

Are they offering a second choice to help prevent you from a choice that could be a potential problem because of some unqualified advice?

At one time I had a bus that had a 2-stroke Detroit diesel engine. Everywhere it stated that you should use a conventional 40 weight oil or 15w40 and no synthetic. I followed their advice to the letter and never had a lubrication problem. Others tried synthetic 15w40 oils and had all kinds of problems from excessive oil consumption, injector pump problems to leaks and piston/ring failures. In fact this might have contributed to the expression that synthetic oil caused leaks.

 

[zeng]

Cat has made it rather clear to me that , in your ambients of 5*C to 20*C,
the 2nd statement applies, namely :
The "Lubricant Viscosities for Ambient Temperatures" on the same page lists -9.5*C as the minimum temp for 15W40.
Cat generally prefers a thicker oil, including powershifts.

 

[George7941]

Zeng, just to clarify, Cat recommended to you 15W40 for service under temperatures similar to mine? Which engine is this?

 

[Garak]

Originally Posted By: George7941
January through March, over the past few winters, I have run the engine on Mobil Delvac 1 0W-40 ESP and I plan to do so again this winter.

How about the Delvac 1 LE 5w30 or Delvac 1 ESP 5w-40? They might be more resistant to shearing. I suspect they would recommend the 0w-40 over the 0w30 on the basis that the 0w30 might have a little less HTHS room than the 0w-40.

 

[dnewton3]

I struggle to understand why folks agonize over these type issues.

The wear data rates contrasting 10w30 to 15w40 are so paltry it's not even worth this discussion. Never has been. Those two oil choices aren't like to make a piddly-darn difference in terms of wear, contrasting one to the other. I have yet to see any proof that the choice between those two lubes makes any tangible difference whatsoever in terms of wear control, strictly using the grade as the variable.

However, being (what I presume might likely be; correct me if I'm wrong here) an HEUI injection system, that might actually make some difference. HEUI likes thinner lubes. Thinner oils also will make cranking easier on the starter motor and batteries; typically will turn over easier. And, that lessor pumping restriction compliments the thinner oil in the injectors firing off quicker. If it's not HEUI, it will still show a slight advantage in cranking over when colder.


Why the OEM confusion is not beyond comprehension. Just as many of us have varying "opinions", so does each board and meeting room at the OEMs. Woulda, coulda, shoulda morphs into some really confusing statements at times in the owner's manual.

Just realize that their recommendations cover a range of grades. You're not going to destroy the engine by selecting one versus another. You might get a bit "better" starting performance, depending upon season and grade. As long as you use a decent qualified API spec (any CJ-4 is going to be just fine), your C7 will be fine.

 

[Shannow]

I've never yet seen an operating and maintenance manual discussed in any detail...let alone mentioned...at a board meeting.

"destroyed" is the standard BITOG strawman.

 

[userfriendly]

Where I work it's called risk analysis. Statistically speaking it's cost over future problems that make or break a plan. Save a little now and spend it later. If it never breaks, then maybe we put those extra bolts in for nothing. If we don't put the extra bolts in and it breaks, then we are much worse off. Now apply that to engine oil. You can only obtain so much information from a urinalysis or two before going for the MRI.
Ten thousand urinalysis isn't going to tell you anymore than the first one or two. If you truly believe that there is absolutely no risk in what you are doing, or trying to achieve, then fly at it. The internet is a wonderful place to learn and grow.

 

[Seadoo]

The answer is simple it says right in the manual use the highest viscosity for your ambient temperature so if it is above -9.5C then 15w40 is the best choice according to the OEM. The 10w30 would be the choice if your ambient temperature is lower than -9.5C

 

[TiredTrucker]

And the manual regarding ambient temperature works how in this situation.... a truck that covers the U.S. and one week is starting up in Florida and the next week in Montana? Obviously one is not going to change the oil weekly, so the recommendation on using the highest viscosity for the ambient temperature is spurious at best. This is the dilemma that many of us in commercial trucking deal with when it comes to OEM lube manuals. For some reason, these things tend to be written in such a way that it seems the OEM doesn't expect the truck to operate outside of a 50 mile radius of the house.

I support dnewton3's suggestion. A 10w30 is going to effectively cover all the bases except the most extremes, and then it might do a fine job as well.

 

[Seadoo]

If you are going to be driving in extreme conditions where you need the high viscosity for Florida and the -18C range in other areas then you would have to go to a synthetic 5w40 or 0w40 CJ-4 product. This way you are getting the proper protection at both ends.

 

[userfriendly]

Seadoo; Read TT's last sentence and see how many of these he knocked over; https://yourlogicalfallacyis.com

Every university program nowadays requires a critical thinking credit or two to survive out in the wild.

 

[Garak]

Originally Posted By: TiredTrucker
I support dnewton3's suggestion. A 10w30 is going to effectively cover all the bases except the most extremes, and then it might do a fine job as well.

10w-30 was the HDEO of choice for many years in this province in the coldest conditions. That was simply all the was available.

 

[George7941]

Tired Trucker, you do bring up a valid point about travel to different regions with different weather. However, in my case, this is a moving company truck doing local deliveries 95% of the time, stays in province 99% of the time, and goes to Quebec maybe a couple of times a year.

 

[The_Eric]

I don't see why see so many refuse to accept the recommendation of a 10w30 over a 15w40 in HD Truck or equipment applications?

The OEM recommends it and countless used oil analysis covering a VERY broad range of power plants support it and yet, the only way to get "proper protection" is to use a 15w40 or maybe a 5w-40.