Synthetic oil

On a similar note, the manuals for our Volvos (car) state every 3K while the dealer tells us every 5K.....so, who do you believe?

I had an 04 F150, new, that came with synthetic oil from the factory. I asked about the break in using synthetic and the dealer said no concerns. Same as the Volvos though, dealer said every 5000 while the manual read, if I recall correctly, every 7500.
 
Originally Posted by Woody:
The longer oil change intervals of synthetics don't make sense.

I thought the longer change intervals were due to the synthetic oil not breaking down as fast as dino oil, and also having a greater ability to absorb compounds that could damage the engine. Or is it motor? ;-)
 
Four Suns said:
Wouldn't that statement depend on the engine? I believe my car holds 3 gallons of oil... no way I'm changing that every 2K miles.
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That's alot of oil. What kind of car? Are you saying that you wouldn't change that often because of cost? I use $1.50/quart oil, I change often, with each change also filter. Clean oil is the secret.
 
As mentioned the synthetics don't break down, less hydroscopic (water absorb) and hold their viscousity over time/temp better. This allows for the longer oil change cycle. However if you are in a dirty environment then change more often, also if you drive short distances where the oil doesn't reach operating temp to help boil off water and gas change more often.

BTW my 97 911 993 C2 uses 12 qts oil (7.5K miles/change), my 07 911 997TT uses 8.5 qts (20K miles/change), both have 2 oil filters and are dry sump engines.

Mike
 
AndersonAcres said:
Originally Posted by Woody:
The longer oil change intervals of synthetics don't make sense.

I thought the longer change intervals were due to the synthetic oil not breaking down as fast as dino oil, and also having a greater ability to absorb compounds that could damage the engine. Or is it motor? ;-)
Click to expand...
There has been some good posts in other threads on oil including "breaking down". I have seen torn down engines full of sludge, what is all that stuff, hows it get in there. I wonder how the sythentics will absorb normal wear particles generated by the engine. How will it absorb some of the minute contaminants entering through the air filter. While oil filters do filter the oil, they don't get everything and we even leave them on longer with synthetics. Seems easier to me just to supply the engine with clean oil and new filters more often.
 
I found the results of this study of oil change intervals to be informative:

http://neptune.spacebears.com/cars/stories/interval.html

TBN, referenced in the link above, is defined at this site: http://www.waynesgarage.com/docs/oil.htm, as "Total Base Number (TBN) -- the quantity of acid, expressed in terms of the equivalent number of milligrams of potassium hydroxide that is required to neutralize all basic constituents present in 1 gram of sample."

They continue "All modern motor oils contain sodium hydroxides (NaOH) to combat the acid build up in the oil. As the oil becomes contaminated and turns acid, the NaOH gets used up. Preventing acid buildup is one of the primary reasons for changing motor oil. Short trip driving is the worst kind of driving for this problem as moisture is not boiled off during driving cycles.

"Because everyone's driving habits are different, everyone's oil gets contaminated at a different rate. And since various oils contain different amounts of NaOH, the only real way to tell if your oil is acid contaminated is by having it analyzed.

"The TBN represents the number of grams of NaOH per kilogram of oil. New oil comes with a TBN number ranging from 5 to 12, depending on the quality of the oil. Store bought oils have a TBN of 6. High quality synthetics have a TBN of as high as 12. When the TBN drops below 2, it’s time to change it."
 
As far as never changing your oil, I have a friend that helped develop ozone disinfection up in napa valley. Last time I saw him he was bragging to me about not changing his oil in his toyota pickup fleet. He installed the aux amsoil filter and the only thing he does is change the filter every 3000 miles and tops off with amsoil. These trucks all had over 200k miles last I talked to him.:grin:
 
tdappleman said:
Off topic.....

Just an fyi on this one.... the 5.0 used here is a 305 block which originates at GM. While the older Mustangs (up to 94) used a 5.0 it was a 302 from Ford and definitely not the same motor. My current Mustang uses the new 3v 4.6 V8 .... just wanted to clarify.
Click to expand...

Off topic a little again...

I was under the impression the Volvo Penta engines were 302 5.0L Ford engines. I do agree that the Mercruiser 5.0 is the 305. I think Volvo has had some engines made by GM though...

Now on with the synthetic versus mineral debate...

I am far from an authority on oils, engines, or boats, but I know that subjects such as this are very subject to bias of various types.

For instance in medicine, we very often see recall bias which is caused by differences in accuracy of recalling past events by cases and controls. There is a tendency for diseased people (or their relatives) to recall past exposures more efficiently than healthy people (selective recall). For example, because women with breast cancer are more likely to remember a positive family history than control subjects, retrospective study designs are likely to overestimate the effect size of family history as a risk factor.

Observation bias is another. For instance consumer reports rates washing machine X as the better buy based on features, price and reliability from surveys of say 5000 users of washing machine X. However if you go to buy a washing machine and your neighbor had a washing machine X break down and flood the house, then the breakdown of your neighbor's washing machine figures more highly in your decision than the reports of 5000 users who may not have had a problem.

Doctors are really bad about doing this, i.e. ordering tests not indicated by scientific literature to evaluate symptom X. However, since the ordering doctor found a rare case of Dr House Disease one time causing symptom X, he orders the test on everyone with the symptom X.

Anyway...
 
Loneranger said:
Doctors are really bad about doing this, i.e. ordering tests not indicated by scientific literature to evaluate symptom X. However, since the ordering doctor found a rare case of Dr House Disease one time causing symptom X, he orders the test on everyone with the symptom X.

Anyway...
Click to expand...

On the other hand, it may be a very rarely occuring disease to a population, but to the patient, it's 100%.
 
This thread is a great read. It reminds me of the current "Bail out Plan" going on as we speak and the division between the parties.

On one side you have the synthetic oil folks who like the results of longevity, increased performance, less vicosity breakdown, etc. On the other side you have the dino or mineral oil crowd who state frequent, regular oil change intervals, and clean oil are the key to making sure your investment is running smoothly. Then there are the ones who are using dino oil and thinking about making the switch over to the synthetics.

Most everyone on this board seems to be fairly consistent in regards to making sure their vehicles are well cared for. I've used the mineral oils for years and haven't had any problems as long as a specific change interval is adhered to and the correct weight is used for the given application. I've also used synthetics and have noticed the ability to extend the change interval due to the technology of the synthetic. Eventually, however, it (oil) must be changed.

As to which is better, more than likely, it is the synthetic. Heck, it's engineered to be better and you will pay more for it up front. The benefit being longer engine life. But, that doesn't mean there is anything wrong with using the mineral based oils, either, as long as the oil is changed regularly.
 
For those using MerCruiser / Quicksilver Synthetic Blend, NMMA FC-W rated, 4 cycle oil, where are you buying it?. I Googled it and did not get a lot of hits.
 
Does this mean a new filter as well? what else for the changover to SYNTH?
 
Synthetic oils do last longer. I ran a test on my Ford Explorer where I ran Mobil 1 for 5,000 miles, took an oil sample, and replaced the oil filter while keeping the old oil in the engine. I did have to use nearly a quart of new oil to replace what I lost in the filter that I replaced. The 5,000 mile old sample tested as vastly superior than brand new dino oil so I waited until 10,000 miles, took another sample while replacing the filter, and that sample still came back as much better than new dino oil. So I did it again at 15,000 miles where the synthetic still tested superior to new dino oil, but was finally starting to show a little wear and was getting down to about the same level as new dino oil quality. This was in a vehicle that sees very hard use.

I cannot help but believe that a full syn would be a great deal for a marine engine since they too are run hard, but those on this thread that adhere to the "use dino oil but chage regularly" are probably just as well off in this case, because most of us change our oil every year... so if you run your boat a hundred hours and then change your oil before splashing again next spring, you would be throwing perfectly good synthetic oil away that you paid a lot more for. So it comes back to the fact that most of us here are good at maintaining our engines, so none of us should worry. But I did want to clarify that yes, syn is vastly superior to dino oil, and that's why it can be used for much longer hours in an engine.

I would like to ask a very pertinent question regarding the original inquiry which was about Merc synthetic blend. A "blend" only has to have synthetic in it to be considered a blend - it does not mean that it is a 50/50 blend. It could be 95 dino / 5 synthetic. Most synthetic "blends" are oil company marketing gimmics that allow them to mix a tiny amount of synthetic into their regular dino oil, package it as a "blend", and sell it for a much higher price to the unsuspectic public who assumes that they are gettting something like a 50/50 mix.

So that begs the question: what is the ratio of syn/dino in Merc's blend?
 
You bring some good info and just based on your research it would seem that the blend is designed to give us great seasonal performance due too us changing oil each winter anyhow. I have syth in mine and each winter it still looks brand new, but hey money grows on trees so I don't mind. I went ahead and changed my oil after recent saltwater trip just as a overkill and it look and smelled like new.:thumbsup:
 
GJarrett said:
Synthetic oils do last longer. I ran a test on my Ford Explorer where I ran Mobil 1 for 5,000 miles, took an oil sample, and replaced the oil filter while keeping the old oil in the engine. I did have to use nearly a quart of new oil to replace what I lost in the filter that I replaced. The 5,000 mile old sample tested as vastly superior than brand new dino oil so I waited until 10,000 miles, took another sample while replacing the filter, and that sample still came back as much better than new dino oil. So I did it again at 15,000 miles where the synthetic still tested superior to new dino oil, but was finally starting to show a little wear and was getting down to about the same level as new dino oil quality. This was in a vehicle that sees very hard use.

I cannot help but believe that a full syn would be a great deal for a marine engine since they too are run hard, but those on this thread that adhere to the "use dino oil but chage regularly" are probably just as well off in this case, because most of us change our oil every year... so if you run your boat a hundred hours and then change your oil before splashing again next spring, you would be throwing perfectly good synthetic oil away that you paid a lot more for. So it comes back to the fact that most of us here are good at maintaining our engines, so none of us should worry. But I did want to clarify that yes, syn is vastly superior to dino oil, and that's why it can be used for much longer hours in an engine.

I would like to ask a very pertinent question regarding the original inquiry which was about Merc synthetic blend. A "blend" only has to have synthetic in it to be considered a blend - it does not mean that it is a 50/50 blend. It could be 95 dino / 5 synthetic. Most synthetic "blends" are oil company marketing gimmics that allow them to mix a tiny amount of synthetic into their regular dino oil, package it as a "blend", and sell it for a much higher price to the unsuspectic public who assumes that they are gettting something like a 50/50 mix.

So that begs the question: what is the ratio of syn/dino in Merc's blend?
Click to expand...

This is what I had heard about synthetics and why Porsche switched to Mobil 1 many years ago, I think the info came from a Porsche factory engineer (same guy that told me about Chevron Techroline). The synthetics don't break down as easily as dino, don't hold water or gas as easily and hold up better at high temps. Someone posted earlier about the dirt that gets into the oil over time..this has me thinking that a very high quality oil filter, changed often as you did makes sense.

So anyone here a chemist that can tell us how and what the synthetics are made of?

Mike
 
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