Yanmar engine oil vs generic

[zeta]

Delo 400, Rotella, Delvac, millions of over-the-road truckers can't be wrong and their engines see far more severe conditions than an occasional sailboat auxiliary. Just my 2 pesos.

[smurphny]

The Yanmar service manual for my 3GM30F lists a number of brands of oil that are acceptable. I use Rotella just because I've used it in a number of diesel engines in the past with good results. Have used synthetic in a Kubota with no problem but I don't know if I'd use it in the Yanmar as synthetics are not on the list in the manual (which was probably written pre-synthetic).

[Music]

Originally Posted by lockie

Next step in my life-long quest to avoid paying through the nose for brand names.........

I'm sure I don't need to use Yanmar oilin my 2GM, but I'd like to hear from people who've successfully used non-Yanmar branded oils for a while.

lockie

Been using Amsoil synthetic for over 10 years. You can extend oil chages if necessary.
They reccommend AMSOIL Power Sports - Online Lookup Guide for Yanmar Diesels.

[four winds]

Now I see this one Music and capngeo referenced is for pre 2007 engines.
The one I posted a link to is for post 2007 engines.

I think the OP is likely to stick with conventional oil considering the stated desire to use a qualified off brand, if I understand correctly. (Rotella 15-40 is readily available and proven)

For me, I think it's safe to assume synthetics are "as good" as conventional oils, at the least. With a couple of possibly distinct advantages, remaining cleaner during the interval and allowing a longer interval if circumstances come up to prevent an on time change, I could be swayed.

But, if it stays so clean where are the contaminates going? Do the contaminates come from combustion by-products, or from the breakdown of conventional oil?

What might be the possible down side of switching to synthetic after 1800 hours and many years using Rotella?

I've always thought the dirty oil is contaminated by carbon compounds(?) from the fuel burning.

[lockie]

Thanks guys, heaps of good info there. Some more of my meagre dollars will now not be wasted merely for the sake of a name on a label.

Appropos: the little pipe between the fuel filter and injector pump sprung a dribble: $20 to fix at the local hose shop, versus around $80 for a genuine newie from the dealers here in Oz! Robin Hood rides again. Ha ha ha ha ha ha!!!!!!!!!!!!!

lockie

[Khagan1227]

Originally Posted by four winds

Now I see this one Music and capngeo referenced is for pre 2007 engines.
The one I posted a link to is for post 2007 engines.

I think the OP is likely to stick with conventional oil considering the stated desire to use a qualified off brand, if I understand correctly. (Rotella 15-40 is readily available and proven)

For me, I think it's safe to assume synthetics are "as good" as conventional oils, at the least. With a couple of possibly distinct advantages, remaining cleaner during the interval and allowing a longer interval if circumstances come up to prevent an on time change, I could be swayed.

But, if it stays so clean where are the contaminates going? Do the contaminates come from combustion by-products, or from the breakdown of conventional oil?

What might be the possible down side of switching to synthetic after 1800 hours and many years using Rotella?

I've always thought the dirty oil is contaminated by carbon compounds(?) from the fuel burning.

First, let me get the disclaimer out of the way and then I'll try to explain.

While I am a certified tribologist (I'll save you the trouble of looking it up: Tribology - Wikipedia, the free encyclopedia ), I do not work, nor am I affiliated in any way to a petrolium products manufacture, except as an end user and a PdM professional.

The advantages of syntethics over mineral oil aren't percieved, they are fact and backed up by every leading lubrication product producer with years of data to prove it. That said, let me explain in the simplist of verbage.

Syntethic oils are produced and blended with PAO (polyolefins). To put it simply, PAOs make syntethic oils more slippery and inprove the lubricating film properties. Since PAOs bond with the metal surfaces of your engine, there is little or no metal to metal contact and thus MUCH less wear products in the oil, which in turn means cleaner oil, and longer oil life. Additionally, most synthetics have better additives which reduce/remove water from your oil (minimizing corrosion) and clean the interior of your engine. Since your oil carries the wear products to the filter, and syns are easier to filter than mineral oils, that results in the contaminates getting left in the filter. Since PAOs help the oil bond with the metal, the interior of your engine remains coated with lubricant MUCH, MUCH longer than with mineral oils. This in turn means your bearings, etc remain lubricated longer and less wear when starting your donk after it has been sitting for any period of time. Another VERY important benefit of syn oil, it maintains it's viscosity over much larger temperature ranges than mineral oil. I.e. the synthetic oils will still flow normally even if the temperature is very cold or very hot.

There are two basic reasons you need to change your oil on a regular basis. Additive depleation and the oil viscosity has increased too much. As oil is used in an engine it gets dirty over time, dirty oil has a higher viscosity (thicker) than new clean oil.

There are other advantages, but again the major advantages are better fuel economy, less corrosion, cleaner oil, longer oil life.

Engines and rebuilds cost a lot of money, synthetic oil costs a few bucks (pounds, euros, etc.) more than mineral. Your call.

[four winds]

Thanks, that all seems reasonable to me.

[Boracay]

Unless my memory is playing tricks my friendly local John Deere dealer didn't stock the special John Deere oil. When I asked they suggested Castrol RX. Got it from my local Repco store.

Calling Castrol and asking for their recomendations would be a good idea.

It's my understanding that synthetic oils are not suited to some engines during their running in period.

[Bash]

I've had Yanmars on the last three boats, current boat included, and have had any number of certified Yanmar mechanics involved in servicing my engines.

Had a Yanmar mechanic ever showed up with Yanmar motor oil, I suspect I'd have fired him on the spot, if for no other reason than for wasting my hard-earned dollars.

Fortunately, I've never had a Yanmar-certified mechanic show such an extreme lack of judgment.

[Dragon Lady]

The main advantage of synthetic oil is that it doesn't break down at high temperatures like mineral oils.
This is an advantage in high performance racing engines, but I'm not sure it's needed in a marine diesel engine.
Fortified mineral oils provide good value for money in medium performance engines ie unsophisticated race engines and top end road cars, but again a nice steady plodder like a marine diesel should be happy with a good quality mineral oil.
The reason oil gets dirty is due to the combustion gases blowing past the piston rings. That’s why a worn engine will dirty its oil quicker.
If you want to know what oil to use I suggest you call the tech expert at your favourite oil company, if they are a real expert and not a salesman they will tell you the best oil to use and most importantly why.

[four winds]

Boracay said "It's my understanding that synthetic oils are not suited to some engines during their running in period." ___________

Also known as the "break in" period. I was going to mention this as well. The reason for this is the fact that the synthetics are so good at reducing friction that during break in the piston rings will not seat (seal) to the bore of the cylinder because so little wear is occurring.

The same thing is related to the oil change interval of modern gas and diesel engines with computer controlled injection (less unburned hydrocarbons blowing by the rings). Old gear heads like me always changed oil in about 3500 miles. I did this with a new car until I learned the recommended 6000-7000 mile interval actually will allow the rings to seat. My gas mileage rose by about 3mpg after I let the oil go 6000 miles and the rings finally seated at over 25,000 miles. This was reported to occur with US diesel trucks as well. Those reports are what convinced me to actually let my oil go for 6000 miles. With my Chevy truck now, I just wait till the oil change light comes on (about 7000-7500 miles) and change it then. Times have changed.

In fact, I believe BMW uses a break in oil before switching to synthetics in their program that provides free scheduled maintenance on their new cars.

I think synthetics have merit. It's just that I always have changed my oil regularly and could not justify the added cost in the past. Today the price difference is less.

I'm on the verge of changing my mind.

[Ironhorse74]

I love oil threads! I was a fleet manager for 2 different large trucking companies. If you travel the interstate highway system in this country, you see their trucks every day. Both used an aggressive oil sampling programing. Both regularly retired trucks with 300k plus miles on them, with the oil that came in the truck from the factory. Take that for what it is worth. Five gallon oil changes versus an oil sampling program, was a financial decision. More than welcome to chew on that one for a while.

[Dragon Lady]

Are you saying you ran 300K without an oil change?
Surely not?
I can see the benefit of oil sampling, it saves us millions on our engines
But we run gas turbines which never need oil changes unless something goes wrong.

[Spirit28]

Just put a new Yanmar 3YM30 in my boat and took the recomendation of an auto mechanic mate of mine (highly value his knowlege on all things mechanical..) who recomended Castrol Seamax Super Plus for the crankcase & Castrol VMX80 for the transmission. I puchased the required amount from him as I couldn't get hold of the small quantity needed for the Yanmar (min purchase 20lt drum!!). Also doubled checked on this site: Castrol Australia - NetLube

Yanmar mechanic turned up to commission the motor & said I should be using Yanmar supplied oil, but he didn't have any in his truck and was very reluctant to use the oil I purchased (I was unaware I had to use Yanmar oil - should have read the manual.... They didn't make a point of it when the motor was dropped in either and I would have purchased if I knew..) Anyway, he did a bit of googling on his Iphone and made a quick phone call, and said its OK to use, but not OK for the VMX80 for the transmission (had to use the Seamax).

Anyway - all still OK and after a grand total of 3 hours on the clock!! Can't believe how easy the motor is to start & quite compared to the old 4 cyl Sole..

btw - while talking about oils, I couldn't get over the sheer number of oil types for motor vehicles my mate has to keep on hand. I counted probably 8-10 44 gal drums of various brands/grades + as many if not more 20lt drums.. He said that just about every manufactuer specifies a different type of oil and even different types within brands/models. His is not a large business, with 5 or so service bays - so I would hate to see what large workshops would need to stock...

[Ironhorse74]

Originally Posted by Dragon Lady

Are you saying you ran 300K without an oil change?
Surely not?
I can see the benefit of oil sampling, it saves us millions on our engines
But we run gas turbines which never need oil changes unless something goes wrong.

What I am saying is that when I was managing fleets we would retire about a quarter of the fleet with the original oil in the engine. 300k plus miles. These we were big fleets, one had over 6000 prime movers.

There is a huge difference in how we use our boat diesels. They sit for long periods of time. Tend to get condensate in them. Sometimes use poor quality, high ash content diesel.