Oil Change Schedule

Oil quality is paramount. By the book timing is the easiest to follow, but I really like O C Diver's method of total fuel burned as the best measure. In cold climes, where the boat will be stored over winter, The best time to change - after following fuel consumption or logged hours - is just before putting her up for the season. Getting all the contaminants out, and fresh oil in is the ultimate engine storage regime. No change needed in spring.

Can't wait to get back in!! (lakes are still frozen)

Schaefferoil wrote;
"Oil quality is paramount"
I use RPM Delo as I belive it's a pluss to use a good oil. But you put so much emphisis on it you may be saying there's poor oil out there. I think it's kinda like cars and boat engines. They are all good but some are a little better.

As it's not recomended I think the "fuel burned" method may be OK most of the time or possibly even better. I could buy into it if it was done on an either-or basis.

Just follow the engine manufacturer's recommendations. Why doesn't that settle the discussion?

take 2 aspirin and call me in the morning....


an old joke but often we have seen it applicable in many situations.


while many manufacturer recommendations are good...are they good enough?

No doubt, Nevertheless, some people enjoy endless discussion.

The manufacturers recomendations may not be best for the product.

When I was flying ultralights I used racing synthetic lubricant. But it was not recomended by the engine manufacturer. They said they didn't have time to test all the different brands and types of synthetic lubricants. They sold their own brand of oil calling it Cuyuna 40-1 oil. The engine was a Cuyuna that was previously a snowmobile engine. I always used Bell-Ray two-stroke racing lubricant. Can't call it an oil because it wasn't ... nor is any other synthetic lubricant that's 100% synthetic. The Bell-Ray stuff was so viscous it could'nt be used w automatic oil injection systems as it was just too thick. But at very high temps thick and viscous is perfect.

So there are times when it's best to not follow the manufacturer's recomendations. But they are very few. I follow Mitsubishi's recomendation to use 30W dino oil.

markpierce said:

Just follow the engine manufacturer's recommendations. Why doesn't that settle the discussion?

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I agree, to a point.

If a manufacturer suggests oil change intervals of say 200 hours and you only put 100 hours on your engine in a season, you won't change your oil at the end of the season? (OK, here in the Salish Sea we don't have seasons as such, but you get the idea).

Mark,
I see you enjoy the conversation enough to be here.

Dave...Exactly the point...it is not that some of us are trying to ignore manufacturers recommendations or trying to be smarter than them...


But as I posted...if engine manufacturers suggest oil changes for "harsh conditions" on one level such as diesel trucks in certain conditions...but only give one recommendation for marine engines (often run in conditions all over the map so to speak by different owners)...then who are they BSing?...there must be flexibility in their recommendations or life just doesn't make sense from one arena to the next.


I would like to think I am one of the educated consumers...not one of the sheep.

manyboats said:

Mark,
I see you enjoy the conversation enough to be here.

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Actually, it has been an irritation. Itches need to be scratched. Regardless, we just change the oil annually with an average of 120 engine-hours.

dhays said:

I agree, to a point.

If a manufacturer suggests oil change intervals of say 200 hours and you only put 100 hours on your engine in a season, you won't change your oil at the end of the season? (OK, here in the Salish Sea we don't have seasons as such, but you get the idea).

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I don't know of any manufacturers who don't also recommend a minimum of once a year. Typically x hours or 1 year, whichever comes first.

BandB said:

I don't know of any manufacturers who don't also recommend a minimum of once a year. Typically x hours or 1 year, whichever comes first.

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Good point. I don't recall the person who mentioned it, but it seems yearly in the fall is a great time for an oil change for the typical low hour weekend warrior. My engine is a lot smaller than most everyone here, but I try and do it spring and fall. Overkill I know.

If I make an offer on the boat that had only 2-3 oil changes in its 6 year life, I will get a thorough engine survey and oil analysis.

dhays said:

Good point. I don't recall the person who mentioned it, but it seems yearly in the fall is a great time for an oil change for the typical low hour weekend warrior. My engine is a lot smaller than most everyone here, but I try and do it spring and fall. Overkill I know.

If I make an offer on the boat that had only 2-3 oil changes in its 6 year life, I will get a thorough engine survey and oil analysis.

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We have no seasons as you and others are referring to. Our winter was four days in a row in February that it didn't hit 70, highs only mid 60's and lows almost down to 50. Fortunately, we were in a warmer climate at the time. I can assure you that long time South Floridians were complaining about how cold it was.

A common thread in this discussion thread is to follow the engine manufacturers' recommendations. While this sounds like great advice there is still one remaining question: Manufacturers recommendations have changed drastically over the years.

The manual for the Volvo MD3B recommends changing oil every 50 hours. Lots of diligent Albin 25 owners are following this recommendation.

The manual for a Perkins 4-108 recommends 100 hour intervals for oil changes.

Many comments on this thread have suggested that a 200+ hour interval is plenty.

So the question is: What has changed?
Are the newer engines somehow better and just don't wear the oil out as fast as older engines?
Or has the oil itself become higher quality over the years?
I guess I'd like to know whether I could go 200 hours on the MD3B, or whether I should stick to the 50 hours stated in the manual. Same for the Perkins 4-108 - 100 hours as recommended, or 200 hours, or?

My guess would be "both". Improved oil, improved engines, increased experience by the manufacturers.

If I were you, I would continue to change the oil at the recommended times using a oil rated at least as high as specified by the manufacturer.

If you don't hit the number of hours, I would change the oil at least once a year.

hrifraf said:

....
I guess I'd like to know whether I could go 200 hours on the MD3B, or whether I should stick to the 50 hours stated in the manual. Same for the Perkins 4-108 - 100 hours as recommended, or 200 hours, or?

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The only way for you to really know is to perform Used Oil Analysis, see the numbers and make a decision.

I have used Blackstone Labs for years for my truck and tractor diesels. I run the truck almost 3 times over the manual recommendation and when I change the oil, I am throwing out good oil. However, that is based on HOW I am using my truck. Same truck operated differently will provide different results. One simply has to do UOA on their engine and see the data. Tis even better to have lots of UOA to build up a trend line on the engine.

Later,
Dan

dannc said:

The only way for you to really know is to perform Used Oil Analysis, see the numbers and make a decision.

I have used Blackstone Labs for years for my truck and tractor diesels. I run the truck almost 3 times over the manual recommendation and when I change the oil, I am throwing out good oil. However, that is based on HOW I am using my truck. Same truck operated differently will provide different results. One simply has to do UOA on their engine and see the data. Tis even better to have lots of UOA to build up a trend line on the engine.

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I have never done this Dan but I am interested. What tests do you have Blackstone run and how often?

dhays said:

My guess would be "both". Improved oil, improved engines, increased experience by the manufacturers.

If I were you, I would continue to change the oil at the recommended times using a oil rated at least as high as specified by the manufacturer.

If you don't hit the number of hours, I would change the oil at least once a year.

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My feeling is the same as your gas. Newer engines are designed for longer service intervals and designed to achieve those through the use of better oils today. We will always meet or exceed the frequency recommended by the manufacturer (we exceed it only when trips planned that would take us over soon so we do it before leaving) and use oils they recommend. We also do oil analysis regularly. Is it more than needed? Perhaps. But then we strive to do more than the minimum in terms of maintenance and upkeep.

If we had a fleet of hundreds of over the road diesels and were convinced through experience and analysis we could change oil less frequently, then that would be an entirely different situation and decision process.

I think some of you may have also missed a very obvious point. Larger oil pans per given size of engine allows you to stretch out the time, or at least the hours, between oil changes. On my sailboat with a D2 55 Volvo Engine, having a 3 gallon crank case, the manufacturer recommends changing oil every 500 hours or once a year. Many of my fellow sailors similar sized engines but only four quart crankcases are changing their oil every hundred hours.

Gordon

Every 100 hours and you are wasting money for no reason.

dhays said:

I have never done this Dan but I am interested. What tests do you have Blackstone run and how often?

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I get a standard test and add a TBN test. TBN(Total Base Number) is a measure of how much additive is left in the oil. I have had oil that had a TBN of 12 or more when new out of the bucket. Supposedly, newer oils do not need higher TBN due to the clean ULSD and have a lower TBN amount when new. Once the TBN gets down towards, say 2 or 3, it is time to change IF there is nothing else going on in the oil prior to that TBN point.

The last test I had done, including TBN, was about $40.

I run a test every oil change. I suppose I could run a test every other test but I just do a test each oil change.

I started testing with the oil being used per the manual and slowly increased the oil change time per the UOA results. I did not really intend to run the oil longer, I was just curious about the oil and when I saw that the oil was in good shape, I just ran longer.

The standard test is describe here, Standard Analysis and TBN is discussed here, Do I Need a TBN?.

Blackstone has some interesting information on oils, Which Oil to Use?

A few years ago they bought some VERY old oil off of EBay, tested it, then ran it in their engines. Based on some of the Internet discussions I have read, one would have expected the engine to have run about 2.3 seconds before blowing up. Some of this oil was in the old containers that one had to push a spout in to use.

Their newsletters are informative as well, Blackstone Labs

Later,
Dan

windmill29130 said:

Every 100 hours and you are wasting money for no reason.

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Pretty blanket statement. Don't you think it depends on:
- engine
- environment
- type of use
- over what length of time those 100 hours were put on the engine?

Personally I agree....every 200 seems to work fine...only if running a vessels engine under severe service would it warrant 100 hr changes.

yes...yes...manufacturer's recommendation is the best idea...even if the engine was designed 50+ years ago....and of course...cheat a little if investing in oil analysis...but don't dare extend it if you aren't.

You betcha if I was running a brand new $25000 diesel I would be following the manufacturers recommendations...even if they said lick the dip stick clean....

But many of us aren't and we are using up to 200 hr intervals that have been proven by many to not make one dang bit of difference.

One other relevant point is the introduction of ULSD, ultra low sulphur diesel. This was done for a few emissions reasons, but the upside for engines was lower soot generation and less acid formation in the sump. Less acid being formed means that oil with a lower initial TBN can be used, and TBN will decrease slower. Less soot formation means... well, less soot in oil.

Those two characteristics were some of the primary reasons for the end of an oil change interval. If your manual was written before introduction of ULSD, then judicious use of the sample analyses may let you stretch it out.

I was taking oil samples when LSD and ULSD was introduced, and soot levels really dropped!! And not by a little.

Brand new engines have the advantage of computers selecting parts.

The cylinder is measured and from hundreds of pistons in the inventory the best fit is selected.

This is part of the reason for longer oil life , the engine IS assembled better.