Which Diesel Engine Oil To Use

[fgarriso]

Im changing my oil, can someone please tell me which oil is best?

these are my specs:

twin marine turbo charged diesels
Ford/Fiat Model: in line 6-cylinder H.P./CU.CI: rep as 155 hp ea engine

This is the current recommendations from the API for your model of engine.

CH-4 Current

Introduced in 1998. For high-speed, four-stroke engines designed to meet 1998 exhaust emission standards. CH-4 oils are specifically compounded for use with diesel fuels ranging in sulfur content up to 0.5% weight. Can be used in place of CD, CE, CF-4, and CG-4 oils.

What you ask for " which oil is best" . The "C" in the API rating is for compression engines which includes diesels. Most common diesels now use 15W40WT oil.

 

[RickyD]

My first diesel mechanic recommended Chevron Delo 400 30w. That was on my Lehman 275s. Now I have Cat 3208s in my Californian. I still use it. Hard to find in just 30w so last time I ordered it from Autozone I think as a special order. No problem. I keep two oil changes aboard but have only needed them when.....I change the oil. I did buy some 15-40w at Costco and I will be using that to top off until gone. Sticking to 30w.

 

[Bacchus]

Eric
I think we are in violant agreement re Viscosity.
Straight 30Wt Dino for boat.
Cars and diesel motorhome are a very different story and for different reasons.

 

[Bacchus]

The MaryAnn
Its best to not start duplicate threads in different sections of TF.
I will merge this one with the general discussion thread with the same topic so you and others will have the benefit of all replies in one location.

 

[Nomad Willy]

Something I’m not familiar w is turbos.
They may need synthetic or/and multi-vis.
See your owner’s manual. It probably had engineering input.

One more thing to consider if you decide t switch to 30w oil is idle speed.
If you back out of your slip immediately after starting when you go into or pass through neutral or put your trans into fwd your engine may die if your idle speed isn’t set high enough.
Do a test first. Start your engine and go more or less immediately into reverse and then neutral. If your engine continues to run in neutral and when you shift into fwd gear your good to go.
Otherwise you may need to adjust up 50rpm or so.

 

[NCheaven]

Mine is turbo - may be why Volvo recommends 15W40. By the way, I finally read Don's recommended article (posting #50) on best oils for marine diesels - Cox Engineering. Very much worth reading! Eye opener.....case for some applications other than most modern, high tech oils. Finished reading, concluding that there are good arguments for a wide range of oil choices - age of engine, use, and more. I'll simply conclude that we're all probably right for our own boats and sleep well tonight......

 

[catalinajack]

I just read the paper referenced in Post #50. I found it interesting but not very helpful. The writer was talking about marine auxiliary engines. What is an auxiliary engine. Generators? Or, would that include my Lehman 120s?

The main concern seemed to be oils with high TBN being used in small engines. I looked up the data sheet for Shell Rotella T1, straight 30 grade oil. It's TBN is 7.5. The writer postulates that the TBN of a cool-running auxiliary engine should be 3 to 4. Confused. Meanwhile, the TBN of Rotella T6 full synthetic is 10.6.

This paper means nothing to me without a clear definition of what is included in "auxiliary " engines.

 

[FF]

"Something I’m not familiar w is turbos.
They may need synthetic or/and multi-vis."

What turbos need the most is a couple of min to cool down with oil flowing , after a hard pull.

If shut down before cooling the lube oil in the simple bearings can coke, "much ungood".

Frequently the time spent docking is enough to cool the turbo.

 

[NCheaven]

Cox Engineering Article

Jack - great comments on that article, which mostly addresses specific matters related to some older, smaller engines. An "auxiliary"? Without looking it up, it's an engine that is a secondary source of propulsion, as an engine on board a sailboat, like my 4.5 hp British Seagull I had on my 1200 pound San Juan 21' (red hull - "Tomato Sloop" - I thought that was clever), but also for some potentially large engines on very large sailing yachts. I wonder if a "get home" engine on a trawler would qualify as an auxiliary? I suspect so. But, the common factor is that these were engines with displacement tasks, whether large or small, more in keeping with Eric's Willard - a classic, well proven displacement trawler. (Aren't they ballasted?) So, to me the Cox Engineering article supported Eric's claims about single weight oils, dino oils, etc., better than the current tech research I had read on oil company web sites, the Tribology site, etc. I'm now more convinced that contributors' thoughts on what is right for their engines makes sense. It doesn't change my mind on what is best for turbo engines like mine with internal temps that rise pretty high with rpm, and per another contributor can "coke" - a scary thought! - or merely cook if oil circulation stops in a very hot engine. That's where the anti-shearing benefits of synthetics comes in - the stats are clear that synthetics have a much higher shearing point and longer life.

So, my concluding point last night that there's ample room to support contributors who mostly seem to be supporting choices that are right for their engines, although API/SAE certifications should be the real guide, making sure that older engines' manual API rating is "covered" by the newer rating. There is at least one oil out there claiming to be effective for engines of pre-2007 manufacturing date, etc. Probably a good choice for some folks.

The real bottom line is that this discussion led me and hopefully others to become more aware of different attributes of different types of oil, and the different needs of various types of engines, ages of engines, and uses of engines that dictate something other than the most advanced oils currently being manufactured. I confess to having been focused on the "best oils" rather than the "best oils for certain engines and applications". (My lawnmower calls for straight 30W, btw, which I provide in dino).

TF provides forums for posing questions, sharing opinions and research, with answers left to each contributor to ponder and adopt for himself/herself. Very Socratic and inductive! Fun!

 

[Rick Hudson]

Read the label

The important thing about the oil you use is not simply the grade (10W-40) but the quality. Strangely, the quality bears no relation to the number of colors printed on the container! In my experience, the more gold & silver on the jug, the more questionable its quality.

Look on the back of the jug for a small circular logo - the API (American Petroleum Institute). This will tell you what the quality of the oil is. Under the API is an S or C designation. S is for gas engines, C is for diesels. Next comes another letter (like 'CK') where the K is a designation of the oils detergent and soot gathering quality. A CK oil is 'better' than a CB, as tested by the API.

Hope this helps.

See also https://www.api.org/-/media/Files/C...-Diesel/Publications/Motor Oil Guide 1020.pdf

 

[Bacchus]

The important thing about the oil you use is not simply the grade (10W-40) but the quality. Strangely, the quality bears no relation to the number of colors printed on the container! In my experience, the more gold & silver on the jug, the more questionable its quality.

Look on the back of the jug for a small circular logo - the API (American Petroleum Institute). This will tell you what the quality of the oil is. Under the API is an S or C designation. S is for gas engines, C is for diesels. Next comes another letter (like 'CK') where the K is a designation of the oils detergent and soot gathering quality. A CK oil is 'better' than a CB, as tested by the API.

Hope this helps.

See also https://www.api.org/-/media/Files/C...-Diesel/Publications/Motor Oil Guide 1020.pdf

While all API grades claim to be "fully compatible" with older API grade specs it doesn't mean the latest is in fact the greatest for all applications.
The latest API deisel oils have been designed & developed to meet OTR applications where emission controls are common. Most marine applications do not fall in this category.
See post #50 for a link that discusses the above.

 

[bayview]

I cant remember ever reading a post about engine failure due to the wrong oil.

 

[bostew]

https://www.dieselpartsdirect.com/
They keep a lot of manuals on engines I found mine there.

 

[Nomad Willy]

Jack,
In this case it means sailboat engine.
Auxiliary = engine on a sailboat.
Yacht = sailboat

Not my description of a yacht (mine has nothing to do w sailboats) but most people in the world especially non-Americans think of or (refer to) a sailboat as a yacht.
An auxiliary engine duty cycle would be much more prone to specify MV oil. An auxiliary engine will be called to perform w/o warm up often or usually much more so than a prime mover. Performing w/o warm up would mean being able to (on a regular basis) provide 50 to 60% of power for docking or perhaps assuming cruise speed on a moments notice.

Auxiliary power often would be a generator. They usually run at normal rpm and load immediately on start-up. For this I would think MV oil would almost be a must.

With a prime mover start up 5 minutes or so before use is almost always the case ... no MV required in the oil. Engines that have the luxury of being warmed up running usually have no need for MV oil.

 

[Nomad Willy]

NCheaven wrote;
“It doesn't change my mind on what is best for turbo engines like mine with internal temps that rise pretty high with rpm, and per another contributor can "coke" - a scary thought! - or merely cook if oil circulation stops in a very hot engine.”

Requirements for high heat has little if anything to do w oil viscosity pertaining to MV. What viscosity the oil is at start-up is not a turbo/heat issue. For turbo lubrication it’s the 40 in (15w40) that is of concern for sufficient oil viscosity for safe lubrication. At higher temps oil thin’s out .. often to the point where the oil film is too thin to give adequate lubrication. Re the lower number (15) high temps haven’t been reached yet so heat isn’t an issue.

At the rather large powerhouse where I worked in Alaska, the 1400hp engine had a turbo but the chief engineer always used Delo 30w oil. However, with todays turbos he’d probably be using multi-vis oil.

Also you may want to know 15w40 oil is not 40 weight oil made to perform like 15w oil when it is cool. It’s 15 weight oil whereas the viscosity improvers give it the viscosity properties of 40 weight oil when it gets to high temps. They start w 15w oil. And if the VI’s loose their abilities to perform the oil reverts back to 15w oil. In the early days of MV oil they mostly marketed 10w30 oil. And after several thousand miles in car engines it did revert back to not far from 10w oil. Now they say that’s an issue of the past but I’ve not seen a study or test to tell how far MV oils go back to their original viscosity.

 

[catalinajack]

Testing will reveal that, don't you think? Every oil test I have had done includes viscosity at operating temp and the original viscosity.

NCheaven wrote;
“It doesn't change my mind on what is best for turbo engines like mine with internal temps that rise pretty high with rpm, and per another contributor can "coke" - a scary thought! - or merely cook if oil circulation stops in a very hot engine.”

Requirements for high heat has little if anything to do w oil viscosity pertaining to MV. What viscosity the oil is at start-up is not a turbo/heat issue. For turbo lubrication it’s the 40 in (15w40) that is of concern for sufficient oil viscosity for safe lubrication. At higher temps oil thin’s out .. often to the point where the oil film is too thin to give adequate lubrication. Re the lower number (15) high temps haven’t been reached yet so heat isn’t an issue.

At the rather large powerhouse where I worked in Alaska, the 1400hp engine had a turbo but the chief engineer always used Delo 30w oil. However, with todays turbos he’d probably be using multi-vis oil.

Also you may want to know 15w40 oil is not 40 weight oil made to perform like 15w oil when it is cool. It’s 15 weight oil whereas the viscosity improvers give it the viscosity properties of 40 weight oil when it gets to high temps. They start w 15w oil. And if the VI’s loose their abilities to perform the oil reverts back to 15w oil. In the early days of MV oil they mostly marketed 10w30 oil. And after several thousand miles in car engines it did revert back to not far from 10w oil. Now they say that’s an issue of the past but I’ve not seen a study or test to tell how far MV oils go back to their original viscosity.

 

[Nomad Willy]

So Jack. What do they say?

Down 2%, 10% more?

 

[catalinajack]

Willy, I was mistaken. The reports only show the tested viscosity. One would need to look at the specs for new oil to see the original viscosity. However, all of my reports have come back saying that the oil was still good to use which means that the viscosity, TBN, and soot levels were all within range. The oil that was tested had an original viscosity of 10.5. Tested it was 11.

So Jack. What do they say?

Down 2%, 10% more?

 

[Nomad Willy]

Thanks Jack,
I think there needs to be more known about this.
Much in the oil business is a mystery.
Not implying there’s significant cheating or misrepresenting of product.
There may be but I doubt there’s much to learn that would change our buying habits.

 

[BeeJay]

Comadave - it's probably fine to feed your Diesel Rotella but I don't think you should be feeding your dog UPS drivers, even if your dog does love them!!!.