What oil comes in the Cummins 6.7L Turbo Diesel

[TiredTrucker]

Fuel economy is probably one aspect of OEM filling with 30w instead of 40w, but not sure how that is a bad thing. A simple tenth of a mile mpg improvement for the average commercial semi truck that averages 120,000 miles a year is almost $1000 in fuel savings. A full mpg better fuel economy rapidly approaches $10K a year in savings. Keep in mind, the move for improved fuel economy is in response to customer demand, and there is no CAFE standards for large commercial trucks. We have one of the clearest examples of the OEM and oil makers meeting the demand of the consumer. A typical semi truck today averages over 25% better fuel economy than just 10 years ago. And there was no government involvement in mandating it!

But engine tolerances are much tighter now. A 30w does an excellent job of protecting the newer motors in these large trucks. Many fleets have fully switched to 30w oils for their trucks and laud the results. I have not seen any instance of degradation of motor longevity when using the 30w oils. Even when going the full 50,000 mile oil change interval that Detroit Diesel recommends now for their DD15 motor. And no, it does not have bypass filtration either. Chevron has done extensive studies on their 10w30 going to 70,000 miles in these applications before starting to approach lower tolerance limits.

 

[CT8]

Originally Posted By: TiredTrucker
Fuel economy is probably one aspect of OEM filling with 30w instead of 40w, but not sure how that is a bad thing. A simple tenth of a mile mpg improvement for the average commercial semi truck that averages 120,000 miles a year is almost $1000 in fuel savings. A full mpg better fuel economy rapidly approaches $10K a year in savings. Keep in mind, the move for improved fuel economy is in response to customer demand, and there is no CAFE standards for large commercial trucks. We have one of the clearest examples of the OEM and oil makers meeting the demand of the consumer. A typical semi truck today averages over 25% better fuel economy than just 10 years ago. And there was no government involvement in mandating it!

But engine tolerances are much tighter now. A 30w does an excellent job of protecting the newer motors in these large trucks. Many fleets have fully switched to 30w oils for their trucks and laud the results. I have not seen any instance of degradation of motor longevity when using the 30w oils. Even when going the full 50,000 mile oil change interval that Detroit Diesel recommends now for their DD15 motor. And no, it does not have bypass filtration either. Chevron has done extensive studies on their 10w30 going to 70,000 miles in these applications before starting to approach lower tolerance limits.
Which makes me want to bring up a subject that that been inside me for many years and now has finally come out of the so to say closet,, Except for freezing cold temperatures why do we need to use syn oil when the conventional oils the last couple of decades and been so good?

 

[CT8]

Originally Posted By: used_0il
My 4500 hp locomotive engine will run 30,000 hours on ZDDP free 20W40 pulling 10,000 tons.
That means your puny 6.7 Cummins pulling a tent trailer can get by on SAE 0W8 or canola cooking oil.
Blasphemy I say blasphemy !

 

[TiredTrucker]

Originally Posted By: CT8
Which makes me want to bring up a subject that that been inside me for many years and now has finally come out of the so to say closet,, Except for freezing cold temperatures why do we need to use syn oil when the conventional oils the last couple of decades and been so good?


Really no reason. All of the HDEO makers seem to have 10w30 CJ-4 in a conventional, but also seem to like to promote their syn blend versions. The 70,000 mile test stuff Delo did was on 10w30.

http://www.deloperformance.com/docs/RE-West-DD15-500K-Service-10W30-Testimonial-FINAL.pdf

From what I gather, it was a conventional oil. The call it their IsoSyn technology, but it is conventional, which leads me conclude it is primarily a Group II+ product.

http://www.deloperformance.com/docs/Delo_400_LE_10W-30.pdf

The vast majority of commercial truck diesels are on conventional motor oils only, it is only the private sector that seems to think that only synthetics will achieve long term engine life.

 

[CT8]

The Forklift dealership I used to work for [17 years] used Delo 400 in every vehicle they owned which was probably 500 assorted size forklifts 3 class 8 trucks, those trucks were run hard, about 20 Ford F350 service vans and few assorted company vehicles and in both sides of the service trucks compressors which were 13 hp gas engines and in the compressors. Also a high number of contract and call in repairs and maintenance the company did .The GP2+ oils work well.

 

[AP9]

Originally Posted By: TiredTrucker
Fuel economy is probably one aspect of OEM filling with 30w instead of 40w, but not sure how that is a bad thing. A simple tenth of a mile mpg improvement for the average commercial semi truck that averages 120,000 miles a year is almost $1000 in fuel savings. A full mpg better fuel economy rapidly approaches $10K a year in savings. Keep in mind, the move for improved fuel economy is in response to customer demand, and there is no CAFE standards for large commercial trucks. We have one of the clearest examples of the OEM and oil makers meeting the demand of the consumer. A typical semi truck today averages over 25% better fuel economy than just 10 years ago. And there was no government involvement in mandating it!


Mostly true, but don't forget 2017 GHG standards. Still, unlike the situation with passenger vehicles, here customer requirements preceded governmental regulatory requirements.



And unlike passenger cars, yes that 0.2% MPG increase by going down a SAE grade will not go unnoticed and cannot be attributed to external factors.

 

[CT8]

Also how many passenger cars get driven 100,000 miles more or less per year using huge amounts of diesel. There is also a huge savings with extended oil change intervals with the same engine life. !3 gallons of oil and the big filters are expensive.

 

[Triton_330]

Here's my 2 cents:

If you're buying a new truck, under warranty, use the oil specified by the dealer as to avoid warranty issues if anything happens.

If you aren't under warranty and/or just don't care about using their spec'd oil...

I would recommend either Delo or Rotella.

~ Triton

 

[TiredTrucker]

Yeah, just follow the recommended vis and classification in the owners manual. Doesn't really matter much what oil is put in at the factory, it will be drained out and then go with what trips your trigger. I have never concerned myself with the brand either my commercial or personal vehicles had for factory fill, or been motivated to even inquire about. A pretty safe bet that what brand they used is not the brand I will use.

 

[CT8]

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