Someone Pls Explain Caterpillar Oil Recommendation

[TiredTrucker]

Habit. Most heavy diesel owners have been on the 40w bandwagon for so long, it is engrained into the psyche of most owners. And the "thicker is better" mantra has been repeated so often that it has become a truth to many. Witness the amount of Lucas OS that is bought by the trucking community. It occupies a major portion of shelf space at truck stops and lube shops that cater to truckers. I have even seen whole pallets of LOS at some commercial truck lube change locations. It is hard to break thru the crusted up brain of some of these folks to allow them to even entertain the idea of a 10w30 being an adequate option.

In all fairness, I had a slow migration to the 30w idea. I had been indoctrinated for many years myself that a 40w was critical. Never got on the LOS bandwagon, so there was still hope for me.

 

[Rob_Roy]

Originally Posted By: George7941


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.


Have you ever had the used oil analyzed? We have a C9 that was putting a lot of fuel into the oil due to some worn injectors.

 

[George7941]

Yes, I have had used oil analysis done and the results show no fuel dilution. BTW what is the oil change intervals on your C9?

About 10W30 vs 15W40, it is Cat themselves that recommend to use the thickest oil that meets cold starting requirements, in this C7. I will try a 10W30 next spring and see how it goes.

I don't think truckers can be blamed for staying with 15W40 because that is what most engine manufacturers recommend for all weather except very cold weather. My experience is limited to pre-2010 engines, maybe recommendations have changed since then.

 

[Seadoo]

Going make this really simple if you operate in these ranges this is what I would recommend based on OEM

-9.5C to anything higher than 40C - 15w40
-18C to 40C - 10w30
anything outside those ranges - 0w40 or 5w40

Hope this clears this up

 

[Garak]

Originally Posted By: George7941
About 10W30 vs 15W40, it is Cat themselves that recommend to use the thickest oil that meets cold starting requirements, in this C7. I will try a 10W30 next spring and see how it goes.

They say that as a general rule, and that is the general rule in diesels. However, they say, as a specific recommendation, to stick with the 10w30.

 

[dnewton3]

Originally Posted By: 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.



Then you've never spent much time in a board room in meetings.
I have sat in discussions for hours where there is no clear answer, because the variability of life offers too much to cover in one simple sentence in a manual. Statements end up conveying the possibilities rather than just giving a clear definitive direction. You can see it often in many different industries.

Admittedly this is not discussed at the highest "board" levels; you're not going to get a CFO and CEO debating this type info. But at lower levels of boards (I use the term as exemplified in my org as a Quality Review Board or QRB), this happens all the time. Don't get hung up on the term "board" room; I was conveying high level discussions about any typical corporate OEM decisions. Let me give you a perfect example in real time from GM/Allison. Do some research and ask if DEX VI is OK to use in pre-2007 transmissions ... Ask Whitewolf and Tom Johnson. There will NEVER be an agreement there, and they sat in the same room for the same discussions.



Bottom line is this; the manual for the C7 is a bit confusing to the OP. But the reality is that either lube (10w-30 or 15w40) will do the job very well. Both will protect against wear equally well; certainly within the margin of normal variation. The grade may make a difference in terms of starting, but that is a unique decision that can be made by each operator depending upon season and regional areas covered (local or national travel).

 

[TiredTrucker]

Originally Posted By: George7941

I don't think truckers can be blamed for staying with 15W40 because that is what most engine manufacturers recommend for all weather except very cold weather. My experience is limited to pre-2010 engines, maybe recommendations have changed since then.


More familiar with Detroit and Cummins than Cat. Detroit (at least in America) has allowed 10w30 as an all season oil in the Detroit 50 and 60 since the early 90's. They have been factory filling with 10w30 for some time, almost since the inception of the DD15 engine. My 2000 year build, and factory rebuilt, Series 60 is getting 10w30. I was influenced by the general trucking consensus for some time regarding 15w40, but that has all changed. Most engine manufacturers now do not recommend 15w40, just allow it. I think only the GM Dmax motor is the last holdout in the OEM mandating a 40w oil. Every truck engine OEM is factory filling with 10w30. If a truck owner does not specify weight when the oil is changed, assuming they are not doing it themselves, then 15w40 will be put in because of the general idea that this is the only applicable oil, again, because of years of ingrained mindset. Go to a truckstop and take your own informal survey and see what the mindset is. The vast majority of truck owners, even with modern 2013 and newer engines, will state that 15w40 is what is needed and 10w30 is just water. The mindset runs deep.

We were using 30w oils in a lot of our diesels from Cat back when my Dad was alive and we were operating them in dozers and such. Never had an oil related problem. Those got operated primarily during hot summer weather in some real nasty conditions. The manuals on those Cat engines allowed using 30w oils.

 

[zeng]

Originally Posted By: 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.


Any clue as to its typical oil sump temperatures variation during winter/summer ?

 

[Garak]

Originally Posted By: TiredTrucker
The vast majority of truck owners, even with modern 2013 and newer engines, will state that 15w40 is what is needed and 10w30 is just water. The mindset runs deep.

It does, even with me. About three or four years ago, a buddy had a Kubota diesel mower. He asked what viscosity he should use. I said something to the effect that it's a diesel, use a 15w40, what else would you use!

 

[George7941]

Originally Posted By: zeng
Any clue as to its typical oil sump temperatures variation during winter/summer ?

I don't know because there is no dash gauge monitoring oil temperature.