Nomad Willy
Guru
kchase,
Re discussion please indicate type of oil.
Re discussion please indicate type of oil.
Rotella T6 Synthetic!!!
- Thread starter Rufus
- Start date
The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.
If you have answers, please help by responding to the unanswered posts.
Nomad Willy
Guru
kchace,
OK good .. dino.
I run my engine at a 50% load 98% of the time. If I had a turbo and ran at 70% I’d run synthetic.
Re my car the dealer said not to change back and forth tween syn and dino and I’ve heard that many times. I suspect that it may have to do w the additive to combat the shrinking. Shrink relax, shrink relax ..... Perhaps the rubber seals don’t like that.
Rotella 15-40 is probably the most common lube oil used on TF. I use Delo 30. Don’t see the need for MV. I always warm my engine up slowly. Even in Alaska it always cranked smartly .. and started normally.
OK good .. dino.
I run my engine at a 50% load 98% of the time. If I had a turbo and ran at 70% I’d run synthetic.
Re my car the dealer said not to change back and forth tween syn and dino and I’ve heard that many times. I suspect that it may have to do w the additive to combat the shrinking. Shrink relax, shrink relax ..... Perhaps the rubber seals don’t like that.
Rotella 15-40 is probably the most common lube oil used on TF. I use Delo 30. Don’t see the need for MV. I always warm my engine up slowly. Even in Alaska it always cranked smartly .. and started normally.
psneeld
Guru
Just to be clear about pour-ability of oil.....
from a marine engineer.... "Hmmmm, last time I looked "pour more freely" was the definition of lower viscosity or "thinner" oil"
From Princeton University - The definition of viscosity
"Viscosity is a measure of a fluid's resistance to flow. It describes the internal friction of a moving fluid. A fluid with large viscosity resists motion because its molecular makeup gives it a lot of internal friction. A fluid with low viscosity flows easily because its molecular makeup results in very little friction when it is in motion."
Best to really understand the oil you chose than going by "rules of thumbs" or perception. No I am not saying use the oil your manufacturer recommended in a 5 year old or even 10 year old manual...but know what different types of oil is really going to do for YOUR engine, how you use it and how you wish to maintain it.
Just like extending oil intervals...I do oil analysis every 100 or so hoursof running. Not because I am concerned with oil wear or engine wear...I am concerned with oil dilution or contamination. Either can signal a major or stop an engine in far less time than engine wear. The oil change could take place AFTER the analysis...but the lag in reports are times well with my cruising style...so it works for me.
from a marine engineer.... "Hmmmm, last time I looked "pour more freely" was the definition of lower viscosity or "thinner" oil"
From Princeton University - The definition of viscosity
"Viscosity is a measure of a fluid's resistance to flow. It describes the internal friction of a moving fluid. A fluid with large viscosity resists motion because its molecular makeup gives it a lot of internal friction. A fluid with low viscosity flows easily because its molecular makeup results in very little friction when it is in motion."
Best to really understand the oil you chose than going by "rules of thumbs" or perception. No I am not saying use the oil your manufacturer recommended in a 5 year old or even 10 year old manual...but know what different types of oil is really going to do for YOUR engine, how you use it and how you wish to maintain it.
Just like extending oil intervals...I do oil analysis every 100 or so hoursof running. Not because I am concerned with oil wear or engine wear...I am concerned with oil dilution or contamination. Either can signal a major or stop an engine in far less time than engine wear. The oil change could take place AFTER the analysis...but the lag in reports are times well with my cruising style...so it works for me.
Last edited:
O C Diver
Guru
- Joined
- Dec 16, 2010
- Messages
- 12,867
- Location
- USA
- Vessel Name
- Slow Hand
- Vessel Make
- Cherubini Independence 45
The 6CT 300 HP Cummins in my charter boat gets run hard. Short warm up followed by 5 minutes of slow operation, then up to 80% for hours. When I get on site, it's slow operation for ten minutes, then shut down. The return trip is the same. First 50 hours uses less than one quart in 50 hours. Somewhere between 50 and 100 hours oil consumption goes to one quart in 6 hours. Oil is black by 25 hours. IMO, the soot levels drive a lot of this. IMO, the soot is likely there regardless of oil type. So, I think it's more beneficial to change the oil in this application every 50 hours. Really don't feel that running 3 times as long with 3 times as much soot is a good idea. Oil analysis with each oil change says everything is good.
My Dodge pickup with a Cummins 6BT 220 HP runs on average at 25% of capacity. Engine has 469,000 miles (9,400 hours) on it and uses less than a quart of oil between oil changes (every 5,000 miles). Oil is amber at oil changes. While oil analysis is still good at 5,000 miles, I don't think extending oil changes to 15,000 miles to justify the use of synthetic makes sense. Feel that additional oil analysis would be required to make sure the additives remain at acceptable levels between oil changes. Also feel that less than 2 oil changes per year is less desirable than 4 to 6.
Ted
catalinajack
Guru
An oil's viscosity rating, 15W-40 for example, only tells part of the story. The 15W number is the rating at 104 degrees. The 40 number is the rating at 212 degrees. At lower temperatures, synthetics do, in fact, pour more freely than do conventional oils despite the nominal SAE rating. It has to do with the molecular structure of the oil. Take a look at the YouTube video I attached. It was a demo performed by Shell Oil. It says all you need to know. Last I knew Shell sells synthetics and conventional so this demo holds no bias. There is a place for both types. Now don't go crazy when you see that the test was done at a temp of -40 degrees. There is a significant difference in pour characteristic at all cold temps. That is why synthetics are better at mitigating cold start-up wear at any temperature as they flow to the internals faster than synthetics. Now, the old wives tale is that 90% of engine wear occurs at start-up and warm-up. If one accepts that synthetics flow better than conventional at any temperature, one must conclude that any engine wil last longer using synthetics.
There will always be non-believers despite science and facts. There is no such thing as global warming/climate change, is there?
There will always be non-believers despite science and facts. There is no such thing as global warming/climate change, is there?
catalinajack
Guru
If the oil analysis on your charter boat comes back "good for continued use" why do you not believe your oil analysis report? I do understand that looking at that black oil is disconcerting but the oil analyses do not lie. However, I have sometimes changed the oil on my Chevy Duramax "just because" even though I really do not need to do that. I did that once at 900 hours even though the test showed no need to do so. That truck still starts and runs as the the I bought it 17 years ago and 292,000 miles.
High Wire
Guru
When we bought Irish Lady, the PO used whatever 15W40 was on sale. 15W40 was not listed in the engine manual. I switched to Rotella T5 10W30 Semi-Synthetic for both engine and gen set. One oil covers both. The lab reports have steadily improved for 5 years. Our Perkins uses 1 qt per 100 hours consistently with over 5200 hours on the clock. Cost is about $15/gal on sale anywhere or from Amazon Prime.
psneeld
Guru
Seems like everyone is right...maybe that's a clue.... 
But where are the traditional oil is cheap and clean oil never hurt an engines guys this go around? I like every opinion under the sun with proof their theory is better.
Also where are the "my buddy never changed the oil in his Toyota corolla for 300,000 miles"...where are those guys?
But where are the traditional oil is cheap and clean oil never hurt an engines guys this go around? I like every opinion under the sun with proof their theory is better.
Also where are the "my buddy never changed the oil in his Toyota corolla for 300,000 miles"...where are those guys?
Nomad Willy
Guru
After reading the Cox Engineering link I ask;
Does any marine engine manufacturer recommend using synthetic lube oil?
Does any marine engine manufacturer recommend using synthetic lube oil?
Ski in NC
Technical Guru
MAN high performance common rail engines require synthetic, at least the models I am familiar with. And I think only some syn oils meet the spec, so
kind of limited selection. Expensive oil changes!!
As far as I know, no others require it.
If I ran a high performance engine, and ran it hard, I probably would use syn whether they recommended it or not. Piston temps get pretty high on those when run hard and dino oil may (will) coke.
Run easy, don't see much benefit.
Nomad Willy
Guru
In post #37 catalinajack wrote;
“An oil's viscosity rating, 15W-40 for example, only tells part of the story. The 15W number is the rating at 104 degrees. The 40 number is the rating at 212 degrees. At lower temperatures, synthetics do, in fact, pour more freely than do conventional oils despite the nominal SAE rating. It has to do with the molecular structure of the oil. Take a look at the YouTube video I attached. It was a demo performed by Shell Oil. It says all you need to know. Last I knew Shell sells synthetics and conventional so this demo holds no bias. There is a place for both types. Now don't go crazy when you see that the test was done at a temp of -40 degrees. There is a significant difference in pour characteristic at all cold temps. That is why synthetics are better at mitigating cold start-up wear at any temperature as they flow to the internals faster than synthetics. Now, the old wives tale is that 90% of engine wear occurs at start-up and warm-up. If one accepts that synthetics flow better than conventional at any temperature, one must conclude that any engine wil last longer using synthetics.”
When I bought my new Mitsu engine I got several oil filters from the engine supplier. Used then and was amazed that my horizontal mounted filter didn’t pour oil out of the filter when removing the filter. I’ve discovered that there was a check valve in the filter that kept the oil in the filter.
Since I used the last of the original filters I started buying filters from NAPA. Those filters do not have the check valve inside and as soon as I unscrew the filter more than a cup of oil comes gushing out.
Does this mean that for several seconds during start-up there is no oil pressure or oil delivery to the bearings? It would seem that oil to the bearings wouldn’t commence until the filter filled up. My logic says yes it should.
If oil flow to the bearings was critical it would seem nobody would manufacture filters that had an unnecessary lag time of oil pressure .. yet they do. Wouldn’t this de-bunk the notion of high engine wear at start-up. I would think so.
As to the “15w” in the viscosity rating (in catjack’s quote above) being taken at 104 degrees (I assume f) we start our engines between 40 and about 80 degrees f. Why do you buy oil with a high flow rating at low temps when you never start your engine at low temps. 10w30 oil was developed for cold starting of motor vehicles that wasn’t an issue above about 10 degrees f. The MV additives clearly aren’t needed in a trawler. Oil in the store is 98% intended for vehicles w engines exposed to outside air and the cold temps found there in the winter.
Re the synthetic oil the Cox guy (probably an engineer) synthetic isn’t recommended. But he dosn’t disclose what his boat is like either. A Donzi probably would benefit whereas a CHB not at all.
Re Ski’s 43 thank you much.
As I suspected.
“An oil's viscosity rating, 15W-40 for example, only tells part of the story. The 15W number is the rating at 104 degrees. The 40 number is the rating at 212 degrees. At lower temperatures, synthetics do, in fact, pour more freely than do conventional oils despite the nominal SAE rating. It has to do with the molecular structure of the oil. Take a look at the YouTube video I attached. It was a demo performed by Shell Oil. It says all you need to know. Last I knew Shell sells synthetics and conventional so this demo holds no bias. There is a place for both types. Now don't go crazy when you see that the test was done at a temp of -40 degrees. There is a significant difference in pour characteristic at all cold temps. That is why synthetics are better at mitigating cold start-up wear at any temperature as they flow to the internals faster than synthetics. Now, the old wives tale is that 90% of engine wear occurs at start-up and warm-up. If one accepts that synthetics flow better than conventional at any temperature, one must conclude that any engine wil last longer using synthetics.”
When I bought my new Mitsu engine I got several oil filters from the engine supplier. Used then and was amazed that my horizontal mounted filter didn’t pour oil out of the filter when removing the filter. I’ve discovered that there was a check valve in the filter that kept the oil in the filter.
Since I used the last of the original filters I started buying filters from NAPA. Those filters do not have the check valve inside and as soon as I unscrew the filter more than a cup of oil comes gushing out.
Does this mean that for several seconds during start-up there is no oil pressure or oil delivery to the bearings? It would seem that oil to the bearings wouldn’t commence until the filter filled up. My logic says yes it should.
If oil flow to the bearings was critical it would seem nobody would manufacture filters that had an unnecessary lag time of oil pressure .. yet they do. Wouldn’t this de-bunk the notion of high engine wear at start-up. I would think so.
As to the “15w” in the viscosity rating (in catjack’s quote above) being taken at 104 degrees (I assume f) we start our engines between 40 and about 80 degrees f. Why do you buy oil with a high flow rating at low temps when you never start your engine at low temps. 10w30 oil was developed for cold starting of motor vehicles that wasn’t an issue above about 10 degrees f. The MV additives clearly aren’t needed in a trawler. Oil in the store is 98% intended for vehicles w engines exposed to outside air and the cold temps found there in the winter.
Re the synthetic oil the Cox guy (probably an engineer) synthetic isn’t recommended. But he dosn’t disclose what his boat is like either. A Donzi probably would benefit whereas a CHB not at all.
Re Ski’s 43 thank you much.
As I suspected.
Last edited:
Nomad Willy
Guru
Ski wrote on post #27,
“Going with syn does not automatically mean you can extend change intervals. Crud added to good oil still ends up being cruddy oil. Sampling is what tells the story. Even dino oil can go well beyond spec change intervals, and it has more to do with engine duty cycle and other stuff, not so much whether dino or syn.”
It would seem to me the only way to get rid of soot and particulate (grit) is to drain the oil when the engine is hot and most solids are in suspension.
How much abrasive wear is caused by this “dirt”?
“Going with syn does not automatically mean you can extend change intervals. Crud added to good oil still ends up being cruddy oil. Sampling is what tells the story. Even dino oil can go well beyond spec change intervals, and it has more to do with engine duty cycle and other stuff, not so much whether dino or syn.”
It would seem to me the only way to get rid of soot and particulate (grit) is to drain the oil when the engine is hot and most solids are in suspension.
How much abrasive wear is caused by this “dirt”?
Nomad Willy
Guru
Rufus wrote on post #25;
“I should have a better sense of the reduction in oil consumption after run time builds on the engines. I probably should have waited to report on my findings before posting, but I was genuinely amazed when I checked the dip sticks.”
Not so IMO.
Look at all the learning and interesting reading that has taken place since.
“I should have a better sense of the reduction in oil consumption after run time builds on the engines. I probably should have waited to report on my findings before posting, but I was genuinely amazed when I checked the dip sticks.”
Not so IMO.
Look at all the learning and interesting reading that has taken place since.
"It would seem to me the only way to get rid of soot and particulate (grit) is to drain the oil when the engine is hot and most solids are in suspension."
Some engines have centrifugal filters and/or bypass filters to help in this area.
FF
Guru
- Joined
- Oct 12, 2007
- Messages
- 22,552
"Oil in the store is 98% intended for vehicles w engines exposed to outside air and the cold temps found there in the winter."
Yes, mostly gasoline cars that do not require cranking speed to cause the fuel to be heated enough by compression to ignite.
"It would seem to me the only way to get rid of soot and particulate (grit) is to drain the oil when the engine is hot and most solids are in suspension."
Yes, heat counts but it takes a good long while for oil detergents to pull the deposited fines back into suspension.
Its great for the engine but not easy to muster the energy to yank 6 gal of oil, change the filter and refill after a long day of having fun!
Yes, mostly gasoline cars that do not require cranking speed to cause the fuel to be heated enough by compression to ignite.
"It would seem to me the only way to get rid of soot and particulate (grit) is to drain the oil when the engine is hot and most solids are in suspension."
Yes, heat counts but it takes a good long while for oil detergents to pull the deposited fines back into suspension.
Its great for the engine but not easy to muster the energy to yank 6 gal of oil, change the filter and refill after a long day of having fun!
ranger58sb
Guru
FWIW...
My normal oil change regime starts with a barnacle run up the river and back... then I drain both engines, both gears, and genset once we're back at the dock.
The engine room is too warm at that point to fool with filters and refill, though, so that's the "tomorrow" part of the project.
-Chris
sunchaser
Guru
- Joined
- Apr 9, 2008
- Messages
- 10,195
- Location
- usa
- Vessel Name
- sunchaser V
- Vessel Make
- DeFever 48 (sold)
Good thread. A few early AM musings -
On Cat powered large dirt moving fleet operations I'm familiar with non synthetics rule. Why? Warranties and cost. As mentioned by Ski and others, synthetic oils don't automatically carry a longer run time.
Cat warranties, a very big deal, require the same oil change intervals. For large fleets, this translates to an increased lube cost of many hundreds of thousands of dollars per year to use synthetics. Hardly makes sense except for those extremely cold operations where synthetics can have the advantage for cold start times.
In our low hour diesel powered recreational marine world virtually any rational oil regime seems logical. Where it gets interesting is in high revving (aren't they all) gas outboards. Some are specked at synthetics for good reason. Given the number of outboards being produced, that is a lot of synthetic oil.
On Cat powered large dirt moving fleet operations I'm familiar with non synthetics rule. Why? Warranties and cost. As mentioned by Ski and others, synthetic oils don't automatically carry a longer run time.
Cat warranties, a very big deal, require the same oil change intervals. For large fleets, this translates to an increased lube cost of many hundreds of thousands of dollars per year to use synthetics. Hardly makes sense except for those extremely cold operations where synthetics can have the advantage for cold start times.
In our low hour diesel powered recreational marine world virtually any rational oil regime seems logical. Where it gets interesting is in high revving (aren't they all) gas outboards. Some are specked at synthetics for good reason. Given the number of outboards being produced, that is a lot of synthetic oil.
Nomad Willy
Guru
psneeld wrote;
“Seems like everyone is right...maybe that's a clue.... ”
How can that be .... but it is.
Some use synthetic some don’t.
Some use MV some don’t.
And w either approach nobody is going to notice their engine wearing out prematurely. As neeld says there are no winners or losers. But we all feel we’re just right enough to mention what we do and what we use and very very few probably change their ways or product.
One thing I would like to know is what (physically) is viscosity improver. I recall hearing it was tiny rubber balls. Could it be?
And on the same subject how long does the viscosity improver last. That is how long does the effects of the VI last. 10w30 is or starts out as 10 weight oil and gets stabilized so it has the viscosity of 10w oil when cold and 30w when hot. So if the VI looses it’s affect the oil is 10 weight .. not 30w.
I have heard down through the years that at change time some viscosity is lost. So what do we wind up with? 10w20? What I heard in the 70’s was worse than 10w20 resulted ... like maybe 10w15 or even 10w oil. Donee wann’a go WOT on 10w oil. And in recent years most seem to say “oh that’s just a thing of the past”. Well ... is it?
“Seems like everyone is right...maybe that's a clue.... ”
How can that be .... but it is.
Some use synthetic some don’t.
Some use MV some don’t.
And w either approach nobody is going to notice their engine wearing out prematurely. As neeld says there are no winners or losers. But we all feel we’re just right enough to mention what we do and what we use and very very few probably change their ways or product.
One thing I would like to know is what (physically) is viscosity improver. I recall hearing it was tiny rubber balls. Could it be?
And on the same subject how long does the viscosity improver last. That is how long does the effects of the VI last. 10w30 is or starts out as 10 weight oil and gets stabilized so it has the viscosity of 10w oil when cold and 30w when hot. So if the VI looses it’s affect the oil is 10 weight .. not 30w.
I have heard down through the years that at change time some viscosity is lost. So what do we wind up with? 10w20? What I heard in the 70’s was worse than 10w20 resulted ... like maybe 10w15 or even 10w oil. Donee wann’a go WOT on 10w oil. And in recent years most seem to say “oh that’s just a thing of the past”. Well ... is it?
ranger58sb
Guru
That has been my logic. Our engines are out of warranty, but the service manual still says every X hours or one year, whichever comes first. [My emphasis]
We usually hit that one year mark... gosh... every year... so any added longevity a synthetic like T6 might bring to the table... would be lost on us... at extra cost.
-Chris
O C Diver
Guru
- Joined
- Dec 16, 2010
- Messages
- 12,867
- Location
- USA
- Vessel Name
- Slow Hand
- Vessel Make
- Cherubini Independence 45
Regarding my charter boat, when an engine goes 50 hours without consuming oil, and then starts consuming a quart every trip or so, I have to assume something has changed with the oil. Assuming it will never be better than when it's new, I have to assume the chance isn't a positive one. An oil change is under $100; a rebuild is around $10,000. I consider it a fairly logical decision.
An oil change on my pickup is around $40. I believe changing the oil every 5,000 miles will get me to 500,000 with the original turbo. Maybe synthetic will get your Chevy there. Guess we will have to wait and see if your truck makes it.
Ted
Marlinmike
Guru
I've actually had opposite results on syn oil that was put in my performance car engine 383 full roller used a bit of oil with syn and none with dino.
Pretty much all new cars are coming full syn now, that 0w number always gives me pause when I pick it up...
Pretty much all new cars are coming full syn now, that 0w number always gives me pause when I pick it up...
clyde
Senior Member
from years of car/truck/boat experience, amsoil is the best full synthetic i`ve found, and10/30 is the best multi-grade! amsoil now makes a 10/30 for diesels! on the shaft vibration problem, all shafts, over 10 ft long, need a center bearing ours is 14 ft, and we put a center bearing behind the 'no drip' shaft seal...voila, no problems! our volvo 70B sits on the enging bed, with a 1/2" rubber pad to cushion it, with 2, 9" lag screws on each side holding it down...no so called motor mounts, it never gets out of allignment!...clyde
Nomad Willy
Guru
Clyde,
Some used Amsoil with their ultralights that used two stroke engines w high performance pipes at very high temps and running for long periods at WOT. High temps from as lean as possible for max power on air cooled engines. Some or more stuck their engines running Amsoil so I’ve steered clear of it. But that was in the late 70’s and early 80’s. So Amsiol has had lots of time to perfect their product. Also the fliers may have stuck their engines for other reasons like cyl head temp gauge not right ect. I used Bel-Ray motorcycle racing oil.
Now I lean toward Mobile-1.
Some used Amsoil with their ultralights that used two stroke engines w high performance pipes at very high temps and running for long periods at WOT. High temps from as lean as possible for max power on air cooled engines. Some or more stuck their engines running Amsoil so I’ve steered clear of it. But that was in the late 70’s and early 80’s. So Amsiol has had lots of time to perfect their product. Also the fliers may have stuck their engines for other reasons like cyl head temp gauge not right ect. I used Bel-Ray motorcycle racing oil.
Now I lean toward Mobile-1.
Nomad Willy
Guru
I think it's all related to the shrinking seal additive.
Last edited:
Civilitas
Senior Member
- Joined
- Feb 20, 2018
- Messages
- 128
- Location
- Air
- Vessel Name
- M/V Peter Iredale ;)
- Vessel Make
- rusting hulk
Clearing up a mistatement repeated above might help get at the viscosity questions still open.
Neither of those statements are correct. "15w" is the "winter" rating of the oil - "w" in a multi-grade oil refers to it's "winter" characteristics. This is a measure of pumpability/cranking viscosity at various winter temperatures. "15w" means it meets the spec (3,500cP) at -15c. Same for "20w", "10w," "5w". The "5" step increments are inverse around the -15c. Like this:
0w -30C (-22F)
5w -25C (-13F)
10w -20C (-4F)
15w -15C (5F)
20w -10C (14F)
25w -5C (23F)
30w 0C (32F)
The warm rating, "30," "40" etc. is viscosity taken at 104F/40C, not 212F.
In the chart above, the oil meets the winter rating and then VII - viscosity index improvers - are added to artificially thicken the oil. They are not durable, do not lubricate, and for oils with a wide viscosity spread (5w-40, e.g.), can be a large part of the oil by weight and volume.
if you take good look a the values above, you can see that unless you routinely start your engine with the engine room below freezing, you are wasting valuable lubrication capability by not running straight-weight oil. You are also gaining no "cold start" benefits.
Nomad Willy asked above about VII's being rubber. In the past, they were. A petroleum engineer explained to a group of us that in fact, in the 80s, they actually recycled tennis shoe soles by grinding them to fine dust and adding them to oil. Nowadays, they are far more highly engineered synthetic molecules, but still the same principal.
This is pretty engine-specific. How hot the oil runs on average and in unique spots, how much shear is experienced in different sections of the engine (internal gears, etc.), total oil volume, presence or not of a turbo, etc. all effect this. Some engines are really easy on oil, and others can chew up the VIIs in short order because of design characteristics.
Gas engines I know better; so let me give an example there - there are gas engines on the road that will destroy an average 5w-30 motor oil in 5 to 6k miles. The same engines can run happily 10k miles on higher quality 10w-30 synthetic (Yes I'm looking at you, Toyota 1mz-fe V6).
CatalinaJack said:
Neither of those statements are correct. "15w" is the "winter" rating of the oil - "w" in a multi-grade oil refers to it's "winter" characteristics. This is a measure of pumpability/cranking viscosity at various winter temperatures. "15w" means it meets the spec (3,500cP) at -15c. Same for "20w", "10w," "5w". The "5" step increments are inverse around the -15c. Like this:
0w -30C (-22F)
5w -25C (-13F)
10w -20C (-4F)
15w -15C (5F)
20w -10C (14F)
25w -5C (23F)
30w 0C (32F)
The warm rating, "30," "40" etc. is viscosity taken at 104F/40C, not 212F.
In the chart above, the oil meets the winter rating and then VII - viscosity index improvers - are added to artificially thicken the oil. They are not durable, do not lubricate, and for oils with a wide viscosity spread (5w-40, e.g.), can be a large part of the oil by weight and volume.
if you take good look a the values above, you can see that unless you routinely start your engine with the engine room below freezing, you are wasting valuable lubrication capability by not running straight-weight oil. You are also gaining no "cold start" benefits.
Nomad Willy asked above about VII's being rubber. In the past, they were. A petroleum engineer explained to a group of us that in fact, in the 80s, they actually recycled tennis shoe soles by grinding them to fine dust and adding them to oil. Nowadays, they are far more highly engineered synthetic molecules, but still the same principal.
NomadWilly said:
This is pretty engine-specific. How hot the oil runs on average and in unique spots, how much shear is experienced in different sections of the engine (internal gears, etc.), total oil volume, presence or not of a turbo, etc. all effect this. Some engines are really easy on oil, and others can chew up the VIIs in short order because of design characteristics.
Gas engines I know better; so let me give an example there - there are gas engines on the road that will destroy an average 5w-30 motor oil in 5 to 6k miles. The same engines can run happily 10k miles on higher quality 10w-30 synthetic (Yes I'm looking at you, Toyota 1mz-fe V6).
Nomad Willy
Guru
OK great post Cavilitas.
I thought if I posted the rubber ball thing someone that had more up to date info would come forth. Thanks.
And as stated before I’m keen on minimizing the VI additives. Only reason I get away w running straight 30w oil in my old car is that I warm it up for 2-5 minutes before driving off. And of course I warm up my boat before slipping the lines. About 5 minutes there too.
In the powerhouse I worked in we ran a 16x20” x 8 cyl turbo diesel on straight 30w Delo. Had a 300 gallon dry sump and heated and circulated the lube oil for 24hrs before starting. Same w coolant. No need for MV there .. and we didn’t use it.
I thought if I posted the rubber ball thing someone that had more up to date info would come forth. Thanks.
And as stated before I’m keen on minimizing the VI additives. Only reason I get away w running straight 30w oil in my old car is that I warm it up for 2-5 minutes before driving off. And of course I warm up my boat before slipping the lines. About 5 minutes there too.
In the powerhouse I worked in we ran a 16x20” x 8 cyl turbo diesel on straight 30w Delo. Had a 300 gallon dry sump and heated and circulated the lube oil for 24hrs before starting. Same w coolant. No need for MV there .. and we didn’t use it.
catalinajack
Guru
With respect Civilitas, let me clear up your misstatements.
I would encourage everyone following this thread to read the Wiki article. For me, it explained everything. I think it will answer everyone's questions and clear up any and all fallacies rendered in this thread. It will also give pause to some with specific engines. Take heed. Here is an example, not a diesle and not in a boat but very interesting, at least to me, and a good reason why this article should be read.
Just last week my brother-in-law told me a car dealer story that I though was pure bull. He owns a Chrysler Pacifica that developed a low oil pressure problem. The dealer asked whether he had changed the oil. He had. Dealer said that was the problem, that the likely cause of the low pressure was a worn oil pump or position sensor, that he should be using only dealer-supplied oil. I called bull, that any oil that meets the SAE spec for that engine is okay. WRONG. Here is what the article said.
Most engines built before 1985 have the flat/cleave bearing style systems of construction, which is sensitive to reducing zinc and phosphorus. For example, in API SG rated oils, this was at the 1200–1300 ppm level for zinc and phosphorus, where the current SM is under 600 ppm. This reduction in anti-wear chemicals in oil has caused premature failures of camshafts and other high pressure bearings in many older automobiles and has been blamed for premature failure of the oil pump drive/cam position sensor gear that is meshed with camshaft gear in some modern engines.
Who would have thunk? I guess dealers are not always telling stories.
The article also contains a good discussion on synthetics. Read that section and take from it what you will. I think it may change some minds. here is an example.
Synthetic oils are derived from either Group III, Group IV, or some Group V bases. Synthetics include classes of lubricants like synthetic esters (Group V) as well as "others" like GTL (methane gas-to-liquid) (Group III +) and polyalpha-olefins (Group IV). Higher purity and therefore better property control theoretically means synthetic oil has better mechanical properties at extremes of high and low temperatures. The molecules are made large and "soft" enough to retain good viscosity at higher temperatures, yet branched molecular structures interfere with solidification and therefore allow flow at lower temperatures. Thus, although the viscosity still decreases as temperature increases, these synthetic motor oils have a higher viscosity index over the traditional petroleum base. Their specially designed properties allow a wider temperature range at higher and lower temperatures and often include a lower pour point. With their improved viscosity index, synthetic oils need lower levels of viscosity index improvers, which are the oil components most vulnerable to thermal and mechanical degradation as the oil ages, and thus they do not degrade as quickly as traditional motor oils. However, they still fill up with particulate matter, although the matter better suspends within the oil,[citation needed] and the oil filter still fills and clogs up over time. So periodic oil and filter changes should still be done with synthetic oil, but some synthetic oil suppliers suggest that the intervals between oil changes can be longer, sometimes as long as 16,000–24,000 kilometres (9,900–14,900 mi) primarily due to reduced degradation by oxidation.
By the way, oxidation is what causes soot formation.
I would encourage everyone following this thread to read the Wiki article. For me, it explained everything. I think it will answer everyone's questions and clear up any and all fallacies rendered in this thread. It will also give pause to some with specific engines. Take heed. Here is an example, not a diesle and not in a boat but very interesting, at least to me, and a good reason why this article should be read.
Just last week my brother-in-law told me a car dealer story that I though was pure bull. He owns a Chrysler Pacifica that developed a low oil pressure problem. The dealer asked whether he had changed the oil. He had. Dealer said that was the problem, that the likely cause of the low pressure was a worn oil pump or position sensor, that he should be using only dealer-supplied oil. I called bull, that any oil that meets the SAE spec for that engine is okay. WRONG. Here is what the article said.
Most engines built before 1985 have the flat/cleave bearing style systems of construction, which is sensitive to reducing zinc and phosphorus. For example, in API SG rated oils, this was at the 1200–1300 ppm level for zinc and phosphorus, where the current SM is under 600 ppm. This reduction in anti-wear chemicals in oil has caused premature failures of camshafts and other high pressure bearings in many older automobiles and has been blamed for premature failure of the oil pump drive/cam position sensor gear that is meshed with camshaft gear in some modern engines.
Who would have thunk? I guess dealers are not always telling stories.
The article also contains a good discussion on synthetics. Read that section and take from it what you will. I think it may change some minds. here is an example.
Synthetic oils are derived from either Group III, Group IV, or some Group V bases. Synthetics include classes of lubricants like synthetic esters (Group V) as well as "others" like GTL (methane gas-to-liquid) (Group III +) and polyalpha-olefins (Group IV). Higher purity and therefore better property control theoretically means synthetic oil has better mechanical properties at extremes of high and low temperatures. The molecules are made large and "soft" enough to retain good viscosity at higher temperatures, yet branched molecular structures interfere with solidification and therefore allow flow at lower temperatures. Thus, although the viscosity still decreases as temperature increases, these synthetic motor oils have a higher viscosity index over the traditional petroleum base. Their specially designed properties allow a wider temperature range at higher and lower temperatures and often include a lower pour point. With their improved viscosity index, synthetic oils need lower levels of viscosity index improvers, which are the oil components most vulnerable to thermal and mechanical degradation as the oil ages, and thus they do not degrade as quickly as traditional motor oils. However, they still fill up with particulate matter, although the matter better suspends within the oil,[citation needed] and the oil filter still fills and clogs up over time. So periodic oil and filter changes should still be done with synthetic oil, but some synthetic oil suppliers suggest that the intervals between oil changes can be longer, sometimes as long as 16,000–24,000 kilometres (9,900–14,900 mi) primarily due to reduced degradation by oxidation.
By the way, oxidation is what causes soot formation.
Similar threads
