synthetic oil

[alexc]

Someone at dockside said if you use synthetic motor oil on your honda, you should not use regular motor oil anymore. I've used regular oil but changed to synthetic. I find the engine is a bit noisier with synthetic though not much. Mine is a 2000 9.9 and used mostly for trolling. I do not believe it affect the engine but just curious if others have other opinion.

 

[hondon]

Re: synthetic oil

Most manufacturers name brand oils i.e. Mercruiser,Honda ,Yamadog,etc,etc,are blended oils ,meaning that they are part petroleum and part synthetic all in the same bottle.With that in mind ,what do you think?

 

[springhead]

Re: synthetic oil

good question al, ive heard the same about synthetic motor oil, once used dont go back to reg oil, also in automobile engines,not sure how true it is.

 

[surfstar]

Re: synthetic oil

it is absolutely untrue. you can switch back and forth if you want, just don't mix them in there at the same time. I use Mobil 1 synthetic in my car, but for an outboard any good marine specific oil should work well.

 

[LubeDude]

Re: synthetic oil

Its absolutly untrue as Surfstar has said. If you are using the same weight you should not have a noisier engine, actually, most seem to say just the opposite. Even mixing synthetic and regular would be ok, they are 100% compatable. Not that I would recomend it as a practice though.<br /><br />What spec does your engine call for?

 

[TOHATSU GURU]

Re: synthetic oil

The "old wives tale" is something about synthetic having a chemical reaction to the seals. Supposedly if you go back to "natural" oil<br />you are prone to getting leaks. I doubt that there is any truth to it. But, I would be careful about using synthetic oil. An undesirable side effect in outboards is that it may cause your engine to run a little too cool. If the engine does not reach operating temp you will use a little more fuel and and you will find fuel in your crankcase. That may necessitate additional oil changes. It's not a problem down here, but up north it is a problem.

 

[LubeDude]

Re: synthetic oil

Originally posted by INTERNETOUTBOARDS:<br /> The "old wives tale" is something about synthetic having a chemical reaction to the seals. Supposedly if you go back to "natural" oil<br />you are prone to getting leaks. An undesirable side effect in outboards is that it may cause your engine to run a little too cool.

Poppy ****!!! "Wives tail" and all of that!!

 

[TOHATSU GURU]

Re: synthetic oil

LubeDude,<br /><br />Are you saying that it is not a side effect of synthetic oils that they cause engines to run a little cooler?

 

[JB]

Re: synthetic oil

Back when fully synthetic oils were introduced for autos. . .1976 or about then, I had an Audi Fox.<br /><br />I put Mobil 1 in it. It suddenly started leaving little puddles of oil in the drive. This was a near-new car that I had bought new and had maybe 30K on it.<br /><br />I took it to my friendly Audi-Porsche dealer and whined. <br /><br />They told me that the seals would not seal the molecular structure of Mobil 1 and not to use it or any other synthetic.<br /><br />I went back to dino oil and the leaks went away.<br /><br />That is when/where the story started. It was true back then. It is no longer true and hasn't been for about 25 years.<br /><br />For example, My ML REQUIRES Mobil 1 or an equivalent synthetic.<br /><br />The story about Synthetics causing outboards to run too cool comes from 4 stroke (only) engines being too well lubricated during break-in to fully seat the rings. That results in fuel in the crankcase. So they recommend not to use synthetics during break in. They also started putting in T'stats for higher running temps.<br /><br />Some confused the "too well lubed" contributor with the "running too cool" contributor and invented a cause-effect relationship that simply isn't there.<br /><br />Isn't it amazing what myths can grow from small, temporary and isolated events?<br /><br />Using synthetics has ZERO chemical effect on your seals. Synthetics and dinos mix well and safely. You can switch anytime you want or mix them.<br /><br />Just don't break in 4 stroke outboards on synthetics unless the maker tells you to.

 

[BillP]

Re: synthetic oil

At least one small engine mfg I know of (onan) actually voids the warranty if you break in with synthetics. They contend the rings don't seat and a glaze happens. The only way to remove the glaze is to hone. Changing to dino oil doesn't fix it. That info is from a local mower shop that caters only to commercial contractors.

 

[LubeDude]

Re: synthetic oil

Originally posted by INTERNETOUTBOARDS:<br /> LubeDude,<br /><br />Are you saying that it is not a side effect of synthetic oils that they cause engines to run a little cooler?

As long as your engines cooling system is functioning properly, Synthetics will have no effect. On the other side, if you are pushing your engine, running synthetics can make a hot engine run a little cooler as they carry heat away better, not to mention the obvious.

 

[TOHATSU GURU]

Re: synthetic oil

Then I stand by my earlier premise " An undesirable side effect in outboards is that it may cause your engine to run a little too cool. If the engine does not reach operating temp you will use a little more fuel and and you will find fuel in your crankcase " This problem occurs often during break-in....and it also occurs AFTER an engine has been broken in if the engine is being run in cold water, low temperature or if the engine is being run at an idle for substantial periods of time. Does everyone who uses a synthetic oil have the problem? No, but enough people have had the problem so that every single manufactuer has a caveat about using synthetic oil in their outboards. In fact, the outboard manufacturers have a new spec in the works for oil called FCW. Its been developed( or maybe it's been around and no one thought to use it) to combat the unique thinning problem that outboards face due to their open cooling systems. Now before everyone tells me I'm wrong please think about this. Your personal expierence may not validate what I'm saying. But, what I'm telling you is factual and is true for a healthy percentage of users across the U.S. Personally, I like synthetic oil and have no problem running it in an automobile. But, I do not recommended that everyone who has an 4-stk outboard switch over to it. <br /><br />Also, the "old wives tale" about synth oil had some basis in fact. As JB indicated, it was back during the mid 70's and may have been limited to just Mobile 1. According to " THEM THAT KNOW SUCH THINGS", Mobile 1 would actually shrink seals, causing leaks. I have no personal knowledge of anyone having this problem, but every legend usually has some basis in fact.

 

[TheOilDoc]

Re: synthetic oil

Origianlly posted by LubeDude:<br /><br />Even mixing synthetic and regular would be ok, they are 100% compatable.

Very bad advice. <br /><br />Base stocks may be compatible, but the oils being mixed are pre-formulated with additives. Not all oil additives are compatible. And even when additives are compatible, it does not mean they are compatible with seal material.<br /><br />Two different oils (sometimes even within the same brand) will have two very different additive formulations. Incompatibility of additives (such as mixing an acidic rust inhibitor with a basic rust inhibitor) can form small, insoluble deposits that compromise seals.<br /><br />Individual oils are chemically formulated to be neutral to seals, or cause them to swell slightly. This is good. But combine additives and you get a bad result. For example: A combination of two oils formulated with different dispersants can attack fluorocarbon seals. A combination of two oils containing ester base stocks can swell seals unacceptably. Silicon seals are especially critical.<br /><br />You can conduct some simple tests yourself to evaluate mixing and compatibility. Combine your two oils and heat. If the mixture becomes cloudy, the oils are not compatible. To test further, add a small amount of water. Mix and continue heating. Allow to sit for half a day. If a solid forms, they are incompatible and seal failure will probably occur. <br /><br />If you want to test to see if both oils have the same water shedding properties (demulsibility), mix the two oils (in a bottle) with an equal amount of warm water. Shake thoroughly and allow to settle. If both oils have good demulsibility, the oil and water layers should separate cleanly with little or no emulsion between the layers. <br /><br />It's ok to use different oils, but not necessarily ok to mix them. It's ok to buy an oil that is a mixture of synthetic and mineral oil (synthetic blend) because this oil will be pre-blended and pre-formulated, compatible with your seals.<br /><br />Oils of today are complex with chemicals and additives. Seal compatibility when mixing them is really a chemistry problem. It's easier to just change it. I recommend you use an oil recommended by the engine manufacturer and use that oil consistently.

 

[BillP]

Re: synthetic oil

WOW, Yeah Baby...keep that info coming!<br />bp

 

[LubeDude]

Re: synthetic oil

Originally posted by TheOilDoc:<br />

Origianlly posted by LubeDude:<br /><br />Even mixing synthetic and regular would be ok, they are 100% compatable.

Very bad advice. <br />

You left off the end of the quote, "Not that I would recomend it as a practice though." <br /><br />Every full synthetic that I know of today claims 100% compatability with conventional oils.

 

[TheOilDoc]

Re: synthetic oil

Compatibility is a term used loosely.<br /> <br />Oxygen and carbon monoxide are compatible too. But it is not the best or safest mixture to breathe. Most all oils will mix. The question is does that mixture provide the best protection for your oil seals?<br /> <br />Royal Purple specifically states that synthetic oil possesses a higher degree of natural solvency, which can clean and remove deposits left by other oils. They go on to say that the removal of these extensive oil deposits can expose marginal or damaged oil seals that may then leak. <br /><br />Amsoil advises that older or higher mileage engines be flushed first before using their oil to ensure that the engine is clean and free of any accumulated contaminates. We know that these accumulated contaminates can cause oil seals to fail once the synthetic oil breaks them loose.<br /><br />These synthetics are only two examples of oils that are compatible with mineral oils, yet obviously react differently in an engine due to their chemical make up.<br /><br />Again, I suggest you consistently use an oil that meets your manufacturer's specification. I do not recommend you practice mixing synthetic brand oils with mineral brand oils at all. Mixing their additive chemistry will not provide optimal protection for your engine, and there is a chance you could experience seal problems.

 

[LubeDude]

Re: synthetic oil

Originally posted by TheOilDoc:<br />[QB] Compatibility is a term used loosely.<br /> /QB]

What part of,<br /><br /><br />"Not that I would recomend it as a practice though."<br /><br />Do you not understand.<br /><br />What little bit of oil left in the pan when changing over to synthetics dosent mean a thing. Ive continually said what you are saying over the years, this is nothing new!<br /><br />Is it OK to mix synthetics with regular oil? Most of the time!<br /><br />Do I recomend it? NO! <br /><br />Same with 2 strokes, Its better to drain clean and refill, but it isnt necesary! <br /><br />You have too much time on your hands if you want to argue something we both agree on.

 

[TheOilDoc]

Re: synthetic oil

Member LubeDude:<br /><br />My intent here is strictly non-confrontational. I am sorry you are (once again) upset by my participation in these discussions.<br /><br />As an oil professional, I must stress that I do not agree with you. <br /><br />In one breath you suggest it's ok to mix synthetic oils with mineral oils. In the next breath you recommend not doing that. Without taking it personally, please understand your statements appear confusing, contradictory, and lacking. You appear to be very argumentative.<br /><br />Performing a search here is something I always do before entering into a discussion. Duplicating information is something I do not have time for. I found nothing posted by you "over the years" (13 months), that reflects what I have posted. You are welcome to take credit for what I have posted if it strokes you. My intent is only to inform members.<br /><br />I am willing to discuss mixing oils further with you, but only professionally.

 

[LubeDude]

Re: synthetic oil

I guess our minds are just not on the same level!!

 

[TOHATSU GURU]

Re: synthetic oil

I think that all of us have something to contribute to these discussions. On any given day anyone of us might answer a question with an absolutely factual response that is 100% true....on the other hand, we might answer the same question a little bit differently and be right(for all practical purposes) but, maybe not right enough for someone who has had a different personal experience. Over the last couple of months I've been second guessed by others a few times. Once, I was flat out wrong. The other times it about practical application instead of theory.( I was right, they were wrong...but, they had a point.) Instead of jumping each other when we differ on a viewpoint, it might be more helpful to preface a response with a " My personal experience is different than you suggest." At least it is less combative