Changing oil and Amsoil

Last fall I replaced the motor oil with Amsoil brand. I have a friend that sells it. He says he goes 15k miles between oil changes. My question is that I only put around 50 hours on the boat this year. He claims that I should not have to change the oil till the end of the season next year. I don't quite feal comfortable doing this. What do you think?

Make yourself comfortable for $30-$40...Is your friend gonna put his money where his mouth is and back it up if something fails? Nope?

You could probably just change the filter.

I've run Amsoil brand synthetics in race cars. The oil stands up well but my oil temp is lower with other brands of synthetics and on the dyno I get more power with Mobil 1 and other brands of synthetics.
You should change the filter, as shred suggested. I would change the oil anyway after 50 hours because you'll have acids that build up in the oil over time. They are caused by the combustion gases and synthetic oil does not stop that part from sitting on your bearings over the winter.
Where synthetics will help the most is if you overheat the oil, and when you have a cold start. You could run more hours with less damage running synthetic, but I would change the oil in the fall after 50 hours.

If you are only putting 50 hours a year on your boat, I would change the oil at the end of the season and run it through the following season, then change it right before storing the boat again. Personally I would not spend the money on Amsoil.

I run Mobil 1 synthetic oil in my boat (and all my other vehicles too). I run the boat and other vehicles right up to the manufacturer's recommend interval before changing. For the boat I use 50 hours or annually.

If I used non synthtic oil I would cut those change intervals in half.

Frank

I would say do not Change intervals just cause you went to Synthetic. This is one of the big reasons PCM doesn't recommend synthetic be used in their engines. Change the oil every 50 hours of one a year which ever comes first.

Also I run Amsoil in mime and stay with the 50 hour mark.

change mine every 100 hours ( twice a season for me) been doin it for years.

There is more to an oil change then just replacing warn out oil with fresh. All engine end up with such things in the crank case such as particulates, condensation, raw fuel, and soot left over from combustion. As the oil circulates, it pick up all this by washing down the inside of the block and cylinder walls. Anything that is solid, should be filtered out by the element, but all the rest is left suspended in the oil. When you drain the old oil, all that contamination is flushed out. For the most part, the lubricating properties of oil really dont wear out, it's all the additives that are added to make it suited for engine oil; like moisture inhibitors, anti-sludge, viscosity modifiers, etc.

It's cheap insurance, change the oil at a regular interval $.02

Amsoil has a funny business plan "use less of our crap" ...

Now that I have drain the block and winterized, I am going to change the oil. In other words, I would have changed the oil prior to winterizing the block so I could run the engine and warm up the oil. But I was taking the advice of my friend. I typically draw the oil through the drain tube on the oil pan with a bucket/pump combo from Jabsco. Should I place a lamp under the block to warm it up so the oil flows out easier?

You'll be pumping that out for days if you don't warm it up first. Warming it up to operating temp makes it so much easier. A lamp under the block will not do the trick, you will never warm the oil up that way. You have to run the boat.

the big issue with boats is that the oil sees more water (humidity in bildge, etc) and water in oil produces acids. that is where the 50 hours mark comes from. synthetic does not help with the fact that the engine is in a marine enviroment and will see more water than traditional applications.

Oops I posted that one in the wrong place... my bad.

I do agree that synthetics are an overkill for boats. Some people do like throwing money away though.

^^^An engine is sealed, how is water going to enter the oil unless there is a leak???

This falls along the smae lines as engines buring oil...they shouldn't unless something is not machined right.

Dirty oil is acidic.You should always change it before long term storage.Unfortunately Doug,not only is it easier to drain when warm,but if you can't fire it up after you change it to distribute the clean oil throughout,it won't do you much good.

Sam,all engines use oil.....it's not a perfect world.Way too many variables contribute to that problem,not just machining.

Engines are not really "sealed" but do have a closed Evaporative system. Ambient air in the crank case turns to condensation when the engine warms up to operating temp, When the engine cools, the steam condenses back to moisture and is left in the top of the engine and, if excessive, as a thin film on top of the oil. The PCV system has the job or removing this condensation but due to the very humid conditions that boats operate in, there will always be some left over. Over time, such as between oil changes, this moisture builds up. This causes poor lubrication, rust, corrosion, etc, so, regular service intervals is the best way to remove all the normal contaminants that accumulate in the oil, no matter how new and engine is, or how well it runs.

So will it really do damage to store the boat with the old oil and change it in the spring?

^^^ Repetadly yes, it's the soft metals such as engine bearings that will pit first.

Sam,

Tigemike put it in a better way than I did. I didn't mean it in the way that water leaks into the engine, but more on the humid air the motor has to live in and inhale (it basically lives in the bilge of the boat.

Synthetics make more sense at higher engine temperatures. Boats run about 170 F where cars and trucks run over 200 to 210 F. Changing regular oil often is cheap and easy. I’d never let old oil sit in my engine over a long set up – as everyone said, it’s the acid.

I have used Amsoil is EVERYTHING i have since 2002. I was put onto it from a friend who is the head of the oil analysis at a nuke plant in Crystal River, Fl. He runs 35,000 miles between oil changes in his personal truck and has been doing this for over 15 years. He pulls a sample of his oil at 3-4K intervals to test it. It gets better with mileage. He changes oil filters ever 10-12K which is the key. I started doing this in my Ford trucks (all powerstrokes) and to this day I run 30K between changes (yes it sounds crazy as I used to think so too). One of them is a 99 with 240K on it . I run it in my wife's van, using a different grade but still amsoil and change her oil ever 25K. I run it in all my atv's, equipment, mowers, etc. I have equipment that will run 50 hrs between changed with standard oil (like rotella t) and have tested it at 400 hrs with Amsoil and the oil is better than when it was poured from the bottle. It is more expensive but you simply can't beat it with any other oil. My powerstroke's cost me $100 to change oil and filters compared to $200-250 if I ran valvoline. In my boats I do change it at the end of each season but still feel better running a better oil, even though it may cost a little more. The auto industry, which my family was in for many years, makes a ton of cash of doing oil changes therefore it only makes sense that they wouldn't want you running a longer life oil. They fought it for years but recently a lot of companies are doing synthetics as they have had no choice. All of my family has now been using it for about 3 years and wouldn't use anything else. My dad, being a car dealer for years, was a tough sell on it but he swears by Amsoil now and every new vehicle he buys gets an oil change the first day. I'd recommend doing some research yourself.

There is not a major difference between the various synthetic oils that meet the various API classifications. Personally, I use the NAPA or whatever is on sale and change the oil every 50 hours or so. Every 100 hours I de-sludge the motor and run two tankfuls with Chevron Techron engine cleaner. I had an engine that seized from a failed oil pickup, and the head and valves were great (the cam seized). Be reasonable and put in fresh oil before any extended layup.

On the intervals. I have a lot of friends that wait and change their oil every spring. I prefer not to let old oil sit over the winter. I replace the oil in the winter and then again in the spring. One thing you do not want to do is let it sit empty as the oil absorbs moisture. It costs me an extra $30 to change the oil, but its worth it to me for the peace of mind.

"He pulls a sample of his oil at 3-4K intervals to test it. It gets better with mileage."

"tested it at 400 hrs with Amsoil and the oil is better than when it was poured from the bottle."


Say What ??

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By Karl De Looff (boarditup) on Sunday, November 16, 2008 - 11:40 am:

There is not a major difference between the various synthetic oils that meet the various API classifications. Personally, I use the NAPA or whatever is on sale and change the oil every 50 hours or so. Every 100 hours I de-sludge the motor and run two tankfuls with Chevron Techron engine cleaner. I had an engine that seized from a failed oil pickup, and the head and valves were great (the cam seized). Be reasonable and put in fresh oil before any extended layup.

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Sorry Karl, you have no idea what you are talking about, synthetic oils are not all the same! When I was getting my degree in mechanical engineering I belonged to SAE (Society of Automotive Engineers) and they had plenty of studies that said otherwise to your opinion. Have you ever heard of Smokey Yunick? He spent five years testing oil on his own in real world racing applications. He found one he liked and ran it at the Indy 500. He used the same oil for both qualifying and the race, he thought it was that good.

Sorry SD that's simply impossible that the oil is in better condition than when it was poured from the bottle, exaggerate much???

Actually, it's not impossible. The oil can be conditioned with heat and other engine by products over time to perform better. Engine lube has come an extremely long way from the stuff that we use in our cars. Use Google's scholarly article search tool and you find many articles about this subject, mostly from the SAE. You can also do a search regarding Formula racing and the new lubricating fluids they are using. Yes, they cost about 10X's what a quart of Valvoline will cost you and they don't make much sense to use in your boat or car. BTW, I'm not saying Amsoil does this, just that it is possible.

Sam if that's the case I need to get some of that stuff because you would never have to change your oil again.

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By nu bu (05mobiuslsv) on Tuesday, November 18, 2008 - 9:51 am:

Sam if that's the case I need to get some of that stuff because you would never have to change your oil again.

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It doesn't work that way. Eventually the chemical compound changes enough with heat and other additives where the lubricating fluid will eventually break down or stop working they way it should. I'm just saying that the formula out of the bottle can be made so that it takes the heat and engine by-products into account and for a period of time it will lubricate better as it heats up or as additives accumulate. At some point you will reach saturation or something similar to that and you will get limiting returns.

Since the discussion has turned to documented sources, where does the 50 hour number come from?

I'm certain that Mercruiser doesn't recommend such a short interval. Can't speak for other brands, but I would guess that they all recommend longer intervals than 50hrs. Another case of 'uncle Jerry was a race car driver so everyone should do what he does'.

Don't worry so damn much. Change per the manufacturer's instructions and use the appropriately rated oil.

^^^^ Marine Power rec's every 50hrs or once a season, FWIW.

I was told that the 50 hour mark was comparable to 3000 miles in a car. Based on what facts,I have no idea. Most people don't drive their v-8 cars @ 3000 rpm. I was also told by my dealer,that was based on the old addage of changing your cars oil @ 3000. While he did not recommend it,he said you could theoretically run well over that with todays technology with no worries.I stick to 50. Then again,I run amzoil in my truck and change it @ 5000.I guess about 25,000 miles prematurely,but I'd rather spend the money on cheap insurance.Facts or no Facts.

In case any of you are wondering and don't know,the extended oil and antifreeze change intervals for modern cars are due solely to EPA requirements to cut down on disposal.They require the manufacture to do that.