Anyone have any thoughts on the pro's or con's of using synthetic oil in a nearly 20yr old Yanmar (that has not had synthetic in it to date)? I know Yanmar used to recommend against it, but has since changed their minds. I've been using plain old 30w Delco diesel motor oil (which seems to work well -- no smoke, no leaks, no burning of oil, etc.). Would engine performance and fuel economy improve by using synthetic oil at this juncture?
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Warren, maybe,,,,,
but you'd have to pull the engine and put it on a dyno to tell. Typically race engines (gas, output-750hp or so) will gain about 5-10 horse power when switched to synthetics. That gain is thought to be because synthetics are generally lower viscosity than standard oil stock. Thusly less internal resistance. For your application,,,forgetaboutit. You have a good thing going and nothing to gain. That's not my opinion. It comes from gurus and users alike.
but you'd have to pull the engine and put it on a dyno to tell. Typically race engines (gas, output-750hp or so) will gain about 5-10 horse power when switched to synthetics. That gain is thought to be because synthetics are generally lower viscosity than standard oil stock. Thusly less internal resistance. For your application,,,forgetaboutit. You have a good thing going and nothing to gain. That's not my opinion. It comes from gurus and users alike.
I'm old enough to remember when
they introduced the synthetic oil, Mobil1. I seem to recall that they proudly trumpeted '25,000 miles between oil changes!!!!!' Now, the interval for synthetics is the same as for natural oil. Seems it isn't so much the oil breaking down, it's the buildup of foreign matter in the oil and filter. So now the synthetics are trumpeting lower friction and better horsepower.... sounds like mission-creep to me..... what's next, nation-building??? I've been told by both auto and boat experts that the single most important thing is to change the oil and filter regularly. Doesn't need synthetics, just fresh stuff. Cheers, Bob s/v X SAIL R 8
they introduced the synthetic oil, Mobil1. I seem to recall that they proudly trumpeted '25,000 miles between oil changes!!!!!' Now, the interval for synthetics is the same as for natural oil. Seems it isn't so much the oil breaking down, it's the buildup of foreign matter in the oil and filter. So now the synthetics are trumpeting lower friction and better horsepower.... sounds like mission-creep to me..... what's next, nation-building??? I've been told by both auto and boat experts that the single most important thing is to change the oil and filter regularly. Doesn't need synthetics, just fresh stuff. Cheers, Bob s/v X SAIL R 8
Transmissions
Sybthetic oil is best to lubricate gears in enclosed casing where there is no contamination. It will last for years. In a combustion chamber with carbon blow-by and foreign particles it needs to be changed at regular intervals so the extra cost is not warranted. It is more heat resistant and maintains viscocity over a longer period but gets dirty just as well. Same goes for those oil additives.
Sybthetic oil is best to lubricate gears in enclosed casing where there is no contamination. It will last for years. In a combustion chamber with carbon blow-by and foreign particles it needs to be changed at regular intervals so the extra cost is not warranted. It is more heat resistant and maintains viscocity over a longer period but gets dirty just as well. Same goes for those oil additives.
Yanmar's Concern for Seals
Having researched this on the yanmarhelp.com site, I thought that Yanmar's concern was for incompatibility of the synthetic oils with their shaft seals.
Having researched this on the yanmarhelp.com site, I thought that Yanmar's concern was for incompatibility of the synthetic oils with their shaft seals.
Good idea for your mechanic, bad for you.
Warren: You can probably bet that if you start using a synthetic now your engine will start to weep. I tried synthetic in my BMW manual tranny when it had about 150,000 miles and ended up having to reseal it. I have two German cars now that use synthetic oils. The oil changes are about 10,000 instead of 2500 - 5000 but the damn oil costs a fortune. These cars were designed to run on this oil, so I will stay with it. You Yanny was designed for good ol' Cx grade conventional oil and I would suggest that you stick with it and change it each year.
Warren: You can probably bet that if you start using a synthetic now your engine will start to weep. I tried synthetic in my BMW manual tranny when it had about 150,000 miles and ended up having to reseal it. I have two German cars now that use synthetic oils. The oil changes are about 10,000 instead of 2500 - 5000 but the damn oil costs a fortune. These cars were designed to run on this oil, so I will stay with it. You Yanny was designed for good ol' Cx grade conventional oil and I would suggest that you stick with it and change it each year.
Synthetic Motor OIl - In my view, I wouldn't
I agree with Bob and Benny. Don't use the stuff, use a high quality grade of oil with the recommended viscosity and change it at reasonable intervals specified for the diesel engine. I suspect if you check with the engine experts at Yanmar and other diesel engine manufacturers, they would agree also.
I agree with Bob and Benny. Don't use the stuff, use a high quality grade of oil with the recommended viscosity and change it at reasonable intervals specified for the diesel engine. I suspect if you check with the engine experts at Yanmar and other diesel engine manufacturers, they would agree also.
Don't Change
I have always been told by the experts not to change the grade or type of oil on an older motor,if its running fine with no problems than don't change,if things are not fine and if its useing oil or smoking or some other problem than try changeing oil but not if everything is good. nick
I have always been told by the experts not to change the grade or type of oil on an older motor,if its running fine with no problems than don't change,if things are not fine and if its useing oil or smoking or some other problem than try changeing oil but not if everything is good. nick
Safe
For inshore no problem, but off shore it is a must anymore, not for more hp or fuel efficiency but reliability. With modern lubes engines are safe, nearly maintanenece free. It cleans inside, no residue on pistones and others... I am a Lubes expert, recomend it for new & young (1000 hours) engines, but certainly not for old engines... it is dangerous...
For inshore no problem, but off shore it is a must anymore, not for more hp or fuel efficiency but reliability. With modern lubes engines are safe, nearly maintanenece free. It cleans inside, no residue on pistones and others... I am a Lubes expert, recomend it for new & young (1000 hours) engines, but certainly not for old engines... it is dangerous...
Steve D, how does the filter last 10,000?
Sure seems like you're going to get the same amount of gunk and crud in the oil, whether it is synthetic or natural, in the same amount of time or miles. Do you use a different filter? Heavy-duty? Long-life? Does the car manufacturer recommend 10,000 mile interval when using synthetic? Sorry if I sound critical, just curious
Cheers, Bob s/v X SAIL R 8
Sure seems like you're going to get the same amount of gunk and crud in the oil, whether it is synthetic or natural, in the same amount of time or miles. Do you use a different filter? Heavy-duty? Long-life? Does the car manufacturer recommend 10,000 mile interval when using synthetic? Sorry if I sound critical, just curious
Cheers, Bob s/v X SAIL R 8
And speaking of life span,
I have a new Duramax diesel. Unbelievable. Wonderful truck. It has sensors in the engine to measure operating conditions of the oil. The computer then tells the driver how much life is left in the oil. The display is on the dash. I bought it in June. Took it to Yellowstone with a two ton camper last summer. The oil, yesterday, is at 44% life remaining at 5000 miles. GM's web site and the owners manual says that the computer could easily not trigger a oil change for over a year. If a year arrives, change it anyway. Don't know why, they don't say. Amazing. The guys I 'bench-race' with are learning about oil change intervals too. The word is, that we change our oil too much with modern engines. Just follow the owners manual.
I have a new Duramax diesel. Unbelievable. Wonderful truck. It has sensors in the engine to measure operating conditions of the oil. The computer then tells the driver how much life is left in the oil. The display is on the dash. I bought it in June. Took it to Yellowstone with a two ton camper last summer. The oil, yesterday, is at 44% life remaining at 5000 miles. GM's web site and the owners manual says that the computer could easily not trigger a oil change for over a year. If a year arrives, change it anyway. Don't know why, they don't say. Amazing. The guys I 'bench-race' with are learning about oil change intervals too. The word is, that we change our oil too much with modern engines. Just follow the owners manual.
Not required.
Bob: I really doubt that there is much crud in the filter in these newer engines. These new engines will last for 300-400k miles if they are taken care of and most of the them have extended oil changes. I think that when these engines are designed for synthetics this is totally different from engines that were not designed that way. The biggest pollutant is usually fuel. This is much easier to control with fuel injected engines. Both of our new vehicles have these extended oil changes (no filter change in between). I just follow the mfg. recommendations. PS: I had a friend that had a Chevy and he NEVER changed the oil. He just added it when it was low. He got rid of the car with over 150k and it was still running. Go figure?
Bob: I really doubt that there is much crud in the filter in these newer engines. These new engines will last for 300-400k miles if they are taken care of and most of the them have extended oil changes. I think that when these engines are designed for synthetics this is totally different from engines that were not designed that way. The biggest pollutant is usually fuel. This is much easier to control with fuel injected engines. Both of our new vehicles have these extended oil changes (no filter change in between). I just follow the mfg. recommendations. PS: I had a friend that had a Chevy and he NEVER changed the oil. He just added it when it was low. He got rid of the car with over 150k and it was still running. Go figure?
Oil Changes
Im an engineer on the CGC Polar Star. We run Alco diesels and only change the oil when we do overhauls. We have two gen sets that have run on syn oil for over two years with no change out, just clean or change the filters.
Im an engineer on the CGC Polar Star. We run Alco diesels and only change the oil when we do overhauls. We have two gen sets that have run on syn oil for over two years with no change out, just clean or change the filters.
Why you may want to
Stay with the 15-40 Delo or Rotella. Synthetics will often cause premature seal leakage not only at the crank but the valves and requires a complete rebuild. Synthetics use a light stock to get the low viscosity rate for start in cold temps and additives to get the higher number for warm engines. The low viscosity is great for cold start as that is when 90% of engine wear occurs. I have driven a CAT powered truck with over 1,000,000 million miles on it that had never been opened up. Part of the reason was it was rarely shut off, therefore with few cold starts. All oils get dirty which causes the wear. The reason you should change once a year no matter how few hours you've run the engine is because of oxidation which causes the oil to become acidic, which eats babbit off of the bearings. You could run the engine constantly, the equivalent of a truck going 30,000 miles and not need to change the oil if done in less than a year. BTW most racing oils don't have anti oxidant in them. I know of a race engine that had race oil in it and they forgot to drain it in the off season and 3 months later the bearings were gone. Oil does not lose its ability to lubricat over time with out external influences. Your refridgerator never needs an oil change because it is a sealed system with no impurities introduced unlike an engine that has fuel and combustion byproducts introduced which change the chemical makeup of the oil. I hope that was simple ennough but if you have questions, e-mail me.
Stay with the 15-40 Delo or Rotella. Synthetics will often cause premature seal leakage not only at the crank but the valves and requires a complete rebuild. Synthetics use a light stock to get the low viscosity rate for start in cold temps and additives to get the higher number for warm engines. The low viscosity is great for cold start as that is when 90% of engine wear occurs. I have driven a CAT powered truck with over 1,000,000 million miles on it that had never been opened up. Part of the reason was it was rarely shut off, therefore with few cold starts. All oils get dirty which causes the wear. The reason you should change once a year no matter how few hours you've run the engine is because of oxidation which causes the oil to become acidic, which eats babbit off of the bearings. You could run the engine constantly, the equivalent of a truck going 30,000 miles and not need to change the oil if done in less than a year. BTW most racing oils don't have anti oxidant in them. I know of a race engine that had race oil in it and they forgot to drain it in the off season and 3 months later the bearings were gone. Oil does not lose its ability to lubricat over time with out external influences. Your refridgerator never needs an oil change because it is a sealed system with no impurities introduced unlike an engine that has fuel and combustion byproducts introduced which change the chemical makeup of the oil. I hope that was simple ennough but if you have questions, e-mail me.
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