Diesel Engine Oil

I have a new-to-me Island Gypsy 32 with a 135 Ford Lehman with 2600 hrs. Bought it last summer and following storage this winter, am ready to change the oil. Boat is used exclusively on Lake Michigan.

I'm getting mixed messages on what oil to use. ADC says 30W (single viscosity). My new mechanic out of Holland, MI, says stick with the 15/40W that the previous owner had used for five years.

Plus, any preference on brand and any other specifics?

Thanks, George

Greetings,
Mr. gb. While I don't have a Lehman 135 (Twin Lehman 120's) I would go with the 30W as advised by ADC. Maybe someone with a manual can substantiate that for you. There are many threads on TF about "what oil?" but my feeling has always been go with what the manual recommends. I use Shell Rotella T 30W single viscosity.

This is a tough one.

My gut says to stick with what the engine is used to but my brain says to use the recommended straight 30wt.

The good thing is that it probably doesn't make any difference.

We do have a FL - 135 - as recommended in the engine manual and Bob Smith at American Diesel, single viscosity - 30 wt - over 1000 hours in the past 3 years with no issues - and we do use Shell Rotella

I had that discussion with Bob Smith several years ago regarding single vs multi and my Lehman 120.
Previous owner had been using 15-40 for quite a while.
He agreed that sticking with the 15-40 was the right thing to do.

According to our local diesel shop the majority of the local fishing boats use 15W40. The most popular oil seems to be Shell Rotella T. Those boats run 10-12 hours a day 6-7 days a week. That is good enough for me.

Incidentally, I would strongly recommend changing the oil in the fall before winter layup rather than letting the engine sit with old, acidic oil over the winter.

When the Lehman manual was written, multi-grade oils had lower lubricating properties than straight grade oils, so they recommended straight. But today multi-grade oils have much better lubricity so I think you will get good performance witht he mult-grades. And in your climate you will get the benefits of easier starting when it is cold.


David

George...
You have reopened the which oil "can of worms"

Here's a previous post w/ lots of opinions, but some good points and links / studies
In my post #46 is a link that I believe is the only marine diesel oil article - all the others are for trucks, etc w/ much different pollution requirements than boats.
See Cox Eng - Best Lubricants for Yacht Engines

My conclusion is go by engine mfg recommendations - use single wt where temps allow (I'm laid up during winter and no need to start in cold weather so I don't need 10W -anything)

I've decided to use 30wt API CF-4 and avoid the latest API classifications (CJ / CI-4) that were implemented for trucks needing to meed pollution stds.
I'd be comfortable w/ any quality oil mfg - Shell - Rotella, Chevron Delo, etc available in your chosen wt / API spec.

Read the links and draw your own conclusion. There are some interesting comments re: synthetic vs dino oils

We used all the time 15 W40 in our FL120 - on our previous boat for 6 years / 1000 hrs as well as on our actual since 3 years / 600 hrs. A friend of us runs since years a turbo charged like you, using also the 15 W40. Don't know your climate at Lake Michigan but it might very similar to ours here in the Southern Baltic. I would be afraid of engine start under cold condition if operating with a W30 ...


best regards / med venlig hilsen
wadden

djmarchand said:

When the Lehman manual was written, multi-grade oils had lower lubricating properties than straight grade oils, so they recommended straight. But today multi-grade oils have much better lubricity so I think you will get good performance witht he mult-grades. And in your climate you will get the benefits of easier starting when it is cold.


David

Click to expand...

+1

If always warm...sure use the 30Wt....

If you are starting in colder temps....then 15W40 is fine.

I have run both in my Lehman during 9 trips from to Florida and New Jersey.......all the time the oil analysis has been perfect.

Both for lubricating and wear.

Modern oils are magic compared to 50 years or so ago when Lehmans were designed.

Oil arguments are fly spit....as long g as you use common sense and stick with decent oils...if in doubt...do oil analysis rather than forum opinions.....maybe not better...but maybe so.....

I use Rotella 15-40 in our FL SP135. I'm not compelled to change. As was stated earlier it probably dosent make much difference unless you are in the Arctic or a tropical climate.

Rotella 15-40. Filter every change. 3500 hours and purrs. Oil looks like new when it comes out approximately every 200 hours.

djmarchand said:

When the Lehman manual was written, multi-grade oils had lower lubricating properties than straight grade oils, so they recommended straight. But today multi-grade oils have much better lubricity so I think you will get good performance with the mult-grades. And in your climate you will get the benefits of easier starting when it is cold.
David

Click to expand...

David
Just curious as I haven't seen this in reports I've read on oils...do you have a reference / report / link that reports the above conclusion.

Tried to go back & re-read the one link I saved that dealt w/ lubricity but found it wouldn't open - report removed???

I use Rotella 15W40 in my 64 Corvair. It has the zinc and lubricants that modern oils and cars do not need. My car originally was also rated for single viscosity 30W oil.

It's an air cooled engine so it runs hotter than regular engines.

Don:


This is from memory and my memory isn't as good as it used to be (there is a C/W song along those lines ;-). But I am also a chemical engineer who worked in the oil industry all my career.


When multi-grade oils first came out they used a synthetic polymer, actually a rubber compound that was mixed with dino oil to extend the viscosity range. But that compound had lousy lubrication properties and degraded the overall mix's lubricity. But it was ok for passenger cars which never stressed the oil very much as they were big cubic inch monsters in those days and were never called on to produce much hp except for a few seconds when the owner goosed it.


But diesels as we all know were designed to run hard and they needed the better lubrication properties of single grade dino oil without the rubber additive.


Today the industry uses an entirely different additive type for multi-grade oils that does have good lubricity properties and are good enough for diesel use. But some diesel manufacturer's either because they were stubborn, or know something that I don't know, never changed and still recommend straight grade oils. Cat and DD are two like that I know of.


But Cummins, Yanmar and Volvo all recommend 15W-40 oil for their diesel engines today.


David

Just for info if anyone is running Cats or is thinking of buying.....

Used Cat or Rotella 15W40 in my 3208 Cats and at the Sea Ray dealership when Sea Rays came with Cats.

The smaller engines did use 40wt per warranty.


https://parts.cat.com/en/catcorp/machine-fluids/oils/diesel-engine-oil/3e-9901-3e-9901-product


DEO 15W-40 (5 L)

Description:
Cat® Diesel Engine Oil is used as standard factory-fill oil for Cat machines


Attributes:
Cat DEO™ is developed, tested and approved by Caterpillar to meet the same high standards as all Genuine Cat Parts.


Recommended Application:
Cat® DEO can be used in diesel engines without aftertreatment devices.

David

Thanks for the response. I'll apologize in advance for the lengthy reply but Ive seen many simple generalizations and the subject is far from simple.

I’m not surprised to hear you are an engineer based on your prior posts & valuable / common sense approach…
I’m a retired mechanical eng w/ no petro experience - just a curious type trying to learn more about diesels.

From what reading I’ve done my understanding is: (correct me if / where I’m off base w/ my assumptions)

Multi-Vis oils are comprised of 3 basic components

1) Base oil – I’m assuming it is multi-vis base oil is neither better nor worse than comparable single vis oil?

2) Viscosity Index modifiers –

a) Used to make a 10wt oil act like 30wt at higher temps to yield a 10W-30 multi vis oil
b) I can believe early VI modifiers were not as effective as modern ones (your point)
What I’m wondering is – are these newer ones actually better than the base oil and impact an improved lubricity that makes the multi-vis superior to single wt or is it that they now don’t detract from the base oil and they are equivalent?
c) I’ve read the following re: VI modifiers…
“Disadvantages
Unfortunately, viscosity index improvers do have some drawbacks. The primary disadvantage is they are susceptible to mechanical shearing. When referring to the slinky analogy, it is easy to imagine a stretched-out slinky cut in half by mechanical processes to produce two shorter slinkys.
As the additive is repeatedly sheared, it loses its ability to act as a more viscous fluid at higher temperatures. Higher molecular weight polymers make better thickeners but tend to have less resistance to mechanical shear. Lower molecular weight polymers are more shear-resistant, but do not improve viscosity as effectively at higher temperatures and, therefore, must be used in larger quantities.”
d) I am assuming the affect of c) above is that over time, as the oil ages & is stressed that the 10W-30 oil starts to act more like 10 wt oil at higher temps – not a good thing in our diesels!?
e) I’ve also read – “modern oils contain viscosity improvers, clever molecules that increase their length when hotter. These are designed to reduce consumption but do not improve the oil's lubrication properties.”
f) Based on e) above I draw the conclusion that regarding lubricity - modern multi-vis oils can be equal to single wt but not better?

3) Additive packages & API Ratings – this is where I get lost as to exactly what the various components of the additive pkg (AP) are and do. Again my reading leads me to believe the following:
a) Much / most of the difference in the latest / “improved” AP’s and latest API diesel ratings (CJ-4) have been pointed at / req’d to meet newer / lower emission regs in OTR trucks for diesels especially those w/ DPF’s (diesel particulate filters)… for example - I understand the level of detergents in CJ-4 oils is limited to reduce DPF plugging
b) One component of the AP is aimed at reducing the acids generated by combustion – this is the TBN # where higher has a greater capacity than lower #’s. I have seen a report that states “There is a great deal of evidence to show that use of an oil with a TBN that is too high for the duty can lead to several problems, particularly high wear rates of cylinder bores.”
c) My 2007 Yanmar 6LYA-STP manual recommends API CD 30wt above freezing (where I boat) or 15W-40 or 20W-40 where temps are below freezing. I’ve research newer manuals and see they have added API CF-4 & after the YM engine was introduced they included the CI-4 ratings but have not endorsed API CJ-4 oils – at least as far as I’ve seen.
d) One learning / conclusion is that the new CJ-4 oils MAY not be better than - in fact may not be as good as - the previous CF / CI-4+ category oils for us boaters (no catalytic converters or diesel particulate filters DPF's)

My take-aways and current practices based on all of this is:

1) Use a CF. CF-2 or CI-4 API rated oil – looking at Shell Rotella as an example that means straight 30wt which is CF/CF-2 rated (other brands e.g. Chevron Delo I consider equally suitable)
2) Avoid CJ-4 rated oils which again using Shell Rotella T Triple 15W-40 is rated CJ-4
3) I have no need to “cold start” my boat engine so see no benefit of multi-vis oil – other than it is readily available and reasonably priced due to the large volume used in trucks.

Most (not all) of the references above are from the Cox Eng Best Lubricants for Yacht Engines report I've referenced before & attached

If you really want the answer to this question the question of why use either one needs to be asked and answered first.

Why do I need MV and/or why do I need straight oil (SW)?

Many say you need MV oil for it's low viscosity .. to flow to where it's needed at startup. I personally think there is plenty of residual oil film even after fairly long peroids of not running. If there was a problem w this the internal combustion engine probably would'nt exist or a solution to that "problem" would be found. Also engine pre-lubricators are very rarely used.


MV oil was created for cold weather operation so if our boat engine compartments were to get cold MV oil may be usefull but most all boats never get below 40 degrees F. Look up the recomendations in most all engine manuals and see that 30W oil covers the enngine needs from 40 degrees to 90 and more so engines don't need MV oil for boats.

So if you think you need MV oil and it makes you feel better go ahead and use it. You'll never know the difference but SW oil is very slightly better. On all my land vehicles I use MV oil ... but not in the boat ... straight 30W all the time. And on my land vehicles I avoid the ultra wide range MV oils. Too much VI .. viscosity improver.

And the answer to the question "why use SW oil" is that it lubricates better ... there is more oil in it and no multiviscosity improvers.

FWIW, Cummins recommends 15W-40 for its QSB engines unless the operating temps are going to be below -15° C. They don't recommend any single weight oil. Granted, these are modern engines, "not your father's diesels".

To be honest, if folks are worried about the long chain multiviscosity agents breaking down over time, then I have to think you are simply not changing your oil often enough.

Next winter change the oil BEFORE storing the boat.

Any acids not neutralized by the used additive package have been chewing on the engine surfaces all winter.

For me single weight still wins .

Change the oil after a long hard run ,all day if you can , while still very hot.

PIA but should do the best job of removing the fines, that work like grinding paste if not removed.

Wow, lots of good information. Personally, I've stuck with using API "CJ" rated oil, Mobil 15W40 in my old Perkins 6-354. We use it in all our diesel generators and diesel vehicles (trucks and my son's VW Golf TDI) and in all our customer's diesel equipment. We've had no lubrication related issues in tens of thousands of hours of use in dozens of pieces of equipment.

In general, I'd say the main thing is to stick with oil bearing the API "C-something" designation, as they're blended for diesels (the symbol S-something being blended for gasoline engines).

Let's be honest here, most of the diesel engines in trawlers have lifetimes so long as to be effectively infinite. I've had engines with 20,000+ hours that still ran as-new with only regular PMs (valve lash adjustment, fluids & filters). The chances of wearing out a modern marine diesel are pretty low.

Onward!

JS

In addition to cold weather easy flowing oil also help get stuff lubed when engines sit a long time as with some boats.


Also consider that diesel fuel is significantly different than when old engines were made. Some of the additives in newer oil compensate for that.


I would be curious about what oil is recommended for construction equipment or city bus and garbage trucks that are always heavily loaded.


In the final analysis I cant remember the last time anyone reported an oil related engine problem despite the abuse and various oils used on zillions of boats.


Slow boats with older engines are probably not all that heavily loaded anyway. Planing boats run at 50 HP per liter are from my point of view.

bayview wrote,
"In addition to cold weather easy flowing oil also help get stuff lubed when engines sit a long time as with some boats."

How does that happen?
Thinner oil will drain off parts like bearings and cylinders sooner and provide less lubrication when startup happens.
Also lube oil pumps are fixed volume gear on gear pumps. They pump a fixed amount of oil or break their drive shaft.
And we're only talking about small amounts of viscosity difference. The same amount of oil will reach the moving engine parts. But it will be slightly higher in viscosity providing better lubrication w SW oil.

SUS viscosity for 15W at 100F is around 200 SUS (Saybolt viscosity).
For 30W at 100F is around 500 SUS (2 1/2 times more viscous/resistant to flow).
100F is just the standard testing temp used for comparison. At colder temps the spread is greater, esp for 30W.

The unanswered question is does this lead to the oil pressure relief valve opening during a cold start? If it does, then there is a lot less oil going to the motor. A clue would be if you can see/tell if the bypass on the filter can is opening during a cold start, it is set lower than the main relief valve.

The oil pressure gauge on the main bearing gallery of my cold diesel jumps up from zero in about 2 seconds or less; that's about 15/20 revolutions.

We can bat this one back and forth over a beer sometime, I'm at the end of J dock when I'm there. (15W-40 Rotella guy)

Nomad Willy said:

bayview wrote,
"In addition to cold weather easy flowing oil also help get stuff lubed when engines sit a long time as with some boats."

How does that happen?
Thinner oil will drain off parts like bearings and cylinders sooner and provide less lubrication when startup happens.
Also lube oil pumps are fixed volume gear on gear pumps. They pump a fixed amount of oil or break their drive shaft.
And we're only talking about small amounts of viscosity difference. The same amount of oil will reach the moving engine parts. But it will be slightly higher in viscosity providing better lubrication w SW oil.

Click to expand...

Stiff cold oil is just harder to get flowing . Any oil on surfaces is better than none.

bayview,
The starter motor seems totally up to the task.

Farrel,
That's a good question about the relief valve. But the issue is flow not pressure. PM me your phone # and I'll ding you next time I'm at the boat.

I would be curious about what oil is recommended for construction equipment or city bus and garbage trucks that are always heavily loaded.

They simply change the oil more frequently.

If 12,000 is OK for an over the road truck with that engine,

6,000 miles would be used in transit or garbage collection.

Nomad Willy said:

bayview,
The starter motor seems totally up to the task.

Farrel,
That's a good question about the relief valve. But the issue is flow not pressure. PM me your phone # and I'll ding you next time I'm at the boat.

Click to expand...

imo you will see pressure up sooner with light oil than heavy . no doubt you change your engine oil on a cold engine in cold weather because you like it to take longer to pump []

FF said:

Next winter change the oil BEFORE storing the boat.

Any acids not neutralized by the used additive package have been chewing on the engine surfaces all winter.

For me single weight still wins .

Change the oil after a long hard run ,all day if you can , while still very hot.

PIA but should do the best job of removing the fines, that work like grinding paste if not removed.

Click to expand...

So, I am wondering how all that acidified oil eats the metal when it all drains down into the oil pan. Also, unless the TBN of the oil has been reduced to an unacceptable level which never happens with regular oil changes which most folks do well before the TBN goes south I just don't see the danger of changing the oil in the spring. IMHO this is just another dock tale and a reason for yards to get more business changing oil that doesn't need changing just like changing oil on a motor vehicle every 3,000 miles, another waste of good oil.