Jump to content
Ultimate Subaru Message Board

synthetic oil MYTHS


Recommended Posts

It's not silly at all. You are talking about impacting the environment, your wallet, and a big investment of time. But largely what we have done here is guesswork. If you want a real answer, then it's got to be based on your specific circumstances. Arguing about oil change intervals is like arguing over how hot you like your shower. What works for some, may not work for all.

 

Here's a good breakdown of current theory's on oil change interval. Many based on good, actual science not the seat of the pants dyno and the reading of chicken bones:

 

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

 

Check out the rest of that site too - there's lots of interesting info including a full on oil analysis of mobile 1 and amsoil at 1,000 mile intervals. The Mobile 1 hung on for 18,000 miles and didn't need a new filter till 12,000 (Wix). This was in a 2002 Z28 Camaro....

 

Here's a tasty quote for ya:

 

"Based on the results we've got here, we'd recommend 8,000 miles between oil changes on an engine that uses no oil at all, perhaps 10,000 miles on an engine that uses some oil, and 15,000 miles or beyond with a filter change every 5,000 miles. This, of course, isn't any kind of guarantee, and you must evaluate for yourself what your engine requires. One thing we're pretty sure about though: 3,000-mile intervals is a huge waste of resources."

 

(no oil company advertising there :eek:)

 

GD

 

Except a 2002 camaro is not a 1980's vintage engine. There are huge differnces between the two, so your compairing apples and oranges.

There are at least 3 generations of emission standards, and that will have a huge effect on how clean the oil is.

Also oil analysis is greta, but it has to be done for the specific engine. you cant just use an analysis of an engine that is at least 12 years newer then the ones on this board. in fact you cant even use an analysis from one 1988 engine to be applied to all 1988 engines.

 

nipper

Link to comment
Share on other sites

  • Replies 69
  • Created
  • Last Reply

Top Posters In This Topic

There are huge differnces between the two, so your compairing apples and oranges.

 

They are both internal combustion engines, and both share piston over crank design... what specifically are the differences that would invalidate this testing? Please provide details. Words like "huge" have no scientific value at all to me or anyone else here.

 

There are at least 3 generations of emission standards, and that will have a huge effect on how clean the oil is.

 

Again with the "huge". Provide accurate data.

 

Also oil analysis is greta, but it has to be done for the specific engine. you cant just use an analysis of an engine that is at least 12 years newer then the ones on this board. in fact you cant even use an analysis from one 1988 engine to be applied to all 1988 engines.

 

Why not? We use the same oil in both. Seems to me that the oil's properties are going to be similar when used in engines rated for similar amount of mileage before rebuild. Both are street gasoline engines. Not race equipment or special service designs.

 

Here's more info for ya from the good people kind enough to offer their Z28 up for analysis. And they bothered to quote sources!

 

"Engine wear actually decreases as oil ages. This has also been substantiated in testing conducted by Ford Motor Co. and ConocoPhillips, and reported in SAE Technical Paper 2003-01-3119. What this means is that compulsive oil changers are actually causing more engine wear than the people who let their engine's oil get some age on it."

 

GD

Link to comment
Share on other sites

Thats like saying the Model T ford is the same as a viper v-10 2007 engine. Some people i will happly educate, and some i choose not too. But just for a rundown. in 1980's the expected engine life was 100K now its 140K, which required differnt materials in the bearings and rings. There were differnt emission standards for each year, which also effects what ends up in the oil. http://ehso.com/ehshome/auto-emissions_chronol.htm

There are two genrations cited (and it takes alot to get those numbers down).

Different drivers will get different results. You wont get the same result from somone who does 100% highway driving as you would 100% city driving. Also any oil testing lab will tell you the same thing, that no two engines are the same.

i am bowing out of this, as i can tell when its not going to make any progress. I am only an automitive engineer with over 20 years expierience, and a certified state inspector, but what do I know.

 

nipper

Link to comment
Share on other sites

Thats like saying the Model T ford is the same as a viper v-10 2007 engine.

 

Not exactly. What we are talking about is an economic Subaru engine - small, low power output, and a design that has proven itself to 200,000+ with relatively little careful maintenance. The analysis was performed with an engine that most would agree would be tired at 200,000 and was built more on the performance end of the spectrum for a sports car. If you look at some of the oil change interval equations, many use a "power" constant to help bias toward more frequent oil changes for higher performance engines. It should also be noted that the Subaru engine was far ahead of the GM engines of the same time period both in construction and materials. The differences are not a large as you might think.

 

If anything (and I'll state right now that this is educated conjecture on my part) all things being equal the EA subaru engine should be able to go LONGER between changes than the Z28 V8. It has a superior lubrication system due to the cylinder oreintation (oil does not as easily drain from the cylinder walls as they are not vertical), and has a comparitively large oil filter for the engine displacement. One can also deduce from the original specifications of 7,500 oil/15,000 filter put out by Subaru in the owners manual that their own engineers came to this same conclusion 20 years ago. The new subaru engine continue this legacy. The owners manual for my friends '06 forester 2.5 reads the same way (after the initial break-in change).

 

It's a general guideline, yes. It would not work for all scenario's, and (just as the authors of that page) I would not sugest that anyone blindly follow those intervals without consideration for their specific situation. But, in the face of no availible statistics for the EA engines, it's better than nothing at all, and most especially better than seat-of-the-pants, and guesswork/conjecture. I'll take a detailed scentific analysis of a similar situation any day over nothing at all. The similarities far outweigh the differences, and in practice one could expect similar numbers from most alloy engines built in the last 40 years.

 

GD

Link to comment
Share on other sites

what engine was in the camaro used??? im not much of a chevy guy, so my late model knowledge is virtually nil.. BUT something tells me it wasn't chevy's latest and greatest.. which means it was likely an apple not too far from the old pushrod tree that first popped up back in the fifties... whereas the ea81/2 block was a fairly drastic departure from subaru's previous blocks, was it not? if nnot, i am certain that one could trace the two motors' antecedents back and rapidly find a point where the subaru design is much much younger. the camaro made ten years prior (92) to the one in the testing GD posted has essentially a 40 year old block design...

 

I am no engineer. I am shadetree, watching this oil debate with a grin of ignorance on my face. However, my thoughts as a man of science are that, these people probnably chose this camaro PRECISELY because the engine design was a marriage of ancientry, and corvette technology. An apple-orange-strawberry-kiwi-mango-melon fruit punch, if you will.

Link to comment
Share on other sites

Synth's big advantage is it's ability to go longer between oil changes before the contaminates saturate the oil.

 

GD

What you just said is like me saying, my pure water will last longer even if I dump a bunch of dirt into it. Its the same amount of oil, so if it took longer to get dirty, wheres the dirt going?

And the 3000s mile BS is from many mechanics who I have talked to about oil and they all agree, 3000 is a good interval. Your stupid if you pay the dealer to change your oil, unless your wife is alone and is incapable, but a caveman(sorry cavemen) could do it. You really think PH balances in an engine that gets that hot??? Acid isnt in oil.

Link to comment
Share on other sites

What you just said is like me saying, my pure water will last longer even if I dump a bunch of dirt into it. Its the same amount of oil, so if it took longer to get dirty, wheres the dirt going?

And the 3000s mile BS is from many mechanics who I have talked to about oil and they all agree, 3000 is a good interval. Your stupid if you pay the dealer to change your oil, unless your wife is alone and is incapable, but a caveman(sorry cavemen) could do it. You really think PH balances in an engine that gets that hot??? Acid isnt in oil.

 

 

...

 

I really don't know what to say to that...

Link to comment
Share on other sites

Kid - you just don't know much about oil, and frankly niether do most "mechanics". See - they make money from changing it, and frankly aren't inclined to change their tune much. If they knew much they would own the shop, or would be engineers. That's the way things work. Very few grease monkeys have a proper education other than "lefty lucy, righty tighty". I've worked with enough to know. There are notable exceptions, and some of them are members here.... you guys know who you are :)

 

Oil contains many things - anti-foaming agents, acid neutralizing agents (acid is a byproduct of combustion [you've heard of acid rain right?], and enters the oil through blow-by gasses}, viscosity modifiers, and many other things. Engine oil is really only about 80% oil with the rest being the "additive package".

 

Now - allow me to educate you on oil theory a bit. First, different oil's have different abilities with regards to "suspension". This is the oil's ability to keep particulates from touching the friction surfaces (if it weren't for this property, oil would do us no good at all with regards to friction). Those particulates bond with impurities already found in non-synthetic oils and tend to settle out more quickly. Synthetic oil has NO impurities by it's very nature (it is created from condensed oil vapors rather than "refined" from a constant liquid state). Thus synthetic oil is more uniform as it's molecule sizes are much more tightly controlled. This gives it's molecule's added abilities with regard to suspension, and molecular adhesion. These features are what allow it to maintain adequate lubrication at higher impurity concentrations. This ability further reduces the tendancy for those impurities to act like "sand" and cause MORE impurities. This further enhances the life of the oil as not only does the synthetic allow the impurities to stay suspended, but it also reduces the delta (rate of change) of impurity production.

 

So what I'm saying in laymans terms is that while you are correct in thinking that the same amount of "dirt" will be there (in some sense, reality is the production of heavy metals is lower), your uniformed conclusion is fualty because you are not aware of the differences that synthetics bring to the equation. I sugest you read up on synthetic oils.

 

GD

Link to comment
Share on other sites

Well. Since my soober isn't up and running at this point I can't weigh in on synth on mine but............

I do run it in my 94 Bravada. It rocks!! Up North we have extreme temp differences. Sometimes 60+ degree swing in 24 hours. Synth is so much better for cold morning startups. It stays cleaner much longer too.

 

I don't use it my oil burning(no leaks) 90 GMC 1/2 ton though. For that I drop in some of the Lucas brand oil treatment. It works super. Try the stuff in with your oil if you have leaks. They also make a kick butt fuel additive. Watch out though. You'll probably be changing a fuel filter but quick from all the crap it busts loose.

Link to comment
Share on other sites

I don't use it my oil burning(no leaks) 90 GMC 1/2 ton though. For that I drop in some of the Lucas brand oil treatment. It works super. Try the stuff in with your oil if you have leaks. They also make a kick butt fuel additive. Watch out though. You'll probably be changing a fuel filter but quick from all the crap it busts loose.

 

Watch what Lucas does to oil:

 

http://www.bobistheoilguy.com/images/lucas/lucas.htm

 

Additives are BOGUS. All the best properties/additives are already present in a *quality* oil additive package.

 

It's one thing to use a "flush" (such as ATF, etc) as a cleaning preperation for SHORT INTERVALS. But don't muck with your oil. There's far, far too many disadvantages to make it worthwhile.

 

GD

Link to comment
Share on other sites

For that I drop in some of the Lucas brand oil treatment. It works super. Try the stuff in with your oil if you have leaks. They also make a kick butt fuel additive. Watch out though. You'll probably be changing a fuel filter but quick from all the crap it busts loose.

 

 

The lucas fuel cleaner IS really good stuff though. I used to use lucas oil stabilizer.. I got roped in by the little pastic gearbox they put in the parts stores when I was a teenager, and I will freely admit it. It helped stop some oil leaks on my Zcar, but then I heard about what it can do, and flushed that motor but-good... No bad news on her yet, but she hasn't been driven in two years either :(

Link to comment
Share on other sites

The lucas fuel cleaner IS really good stuff though.

 

Perhaps, but much like Dewalt tools (owned by black and decker.... don't get me started), I wouldn't buy the stuff to find out. I refuse to support companies that make crappy products by purchasing their other products that "aren't as high on the crap roster".

 

GD

Link to comment
Share on other sites

In my opinion oil additives are a waste of money. There is a reason why porsches, Corvettes, BMW's, and other high end vehicles come from the factory with MOBIL1. Synthetic oil is superior to regular oil. My RX came with every single reciept from every oil change. It always had regular oil. When I filled it with synthetic, it ran smoother and seemed to rev faster. I would find it hard to believe that someones car did not run as good with synthetic oil as it did with regular. I preach MOBIL1 and always will. Every car I have ever owned has seemed to run better with synthetic oil. If oil additives were all that they are advertised to be then they would come in cars from the factory and be recommended by the manufacturer. Synthetic oil will do anything for your engine that regular oil combined with additives will.

Link to comment
Share on other sites

In my opinion oil additives are a waste of money. There is a reason why porsches, Corvettes, BMW's, and other high end vehicles come from the factory with MOBIL1. Synthetic oil is superior to regular oil. My RX came with every single reciept from every oil change. It always had regular oil. When I filled it with synthetic, it ran smoother and seemed to rev faster. I would find it hard to believe that someones car did not run as good with synthetic oil as it did with regular. I preach MOBIL1 and always will. Every car I have ever owned has seemed to run better with synthetic oil. If oil additives were all that they are advertised to be then they would come in cars from the factory and be recommended by the manufacturer. Synthetic oil will do anything for your engine that regular oil combined with additives will.

+1 except that synthetic does MORE than regular oil with additives!!!

Link to comment
Share on other sites

maybe I am not talking apples and oranges here, but 3000 mi oil changes sound very out dated for gas motors, especially when comparing the Diesel freighliner/dodge vans which require an oil change at 10,000 mi regardless of the type of driving, but then again they are useing synthetic 0/40 or 5/40 with a canister type oil filter.....I had an oil analysis done for all my vehicles.. at least a couple times around and found that I could easily extend my drain intervals two times longer and even more then that on my 86 turbo diesel...generally speaking, for off the shelf oil filters,... improvements to this item have lagged far behind...if I had a canister type filter(5-10 micron removal) from VW attached to my 86 diesel and useing synthetic oil would extend the drain interval even further...

Link to comment
Share on other sites

On Castrols web site they still promote the 3000mi oil change (shame on them) regardless if conventional. or syn. oil is used...while the Valvoline site seems to be more honest and only recommend a conventional oil for my 01 Outback and also that I stay with the manufactures oil change intervals..synthetic was not recommended by valvoline because I don't live in the extreme cold or hot climates and I don't pull a trailer...conventional oils have worked fine for both my mid 80's subarus and still my 86 turbo will pass the emissions test with no problem..all this with only 4-5000 mi oil changes on a motor with 206,000mi and still going strong...

Link to comment
Share on other sites

Nipper..That is fine if you do not want to buy a car with 10,000 mi oil change intervals..but can you explain why for example Honda with their "so called" computer oil monitoring system would have no problem doing oil changes to their new vehicles even at 12,000mi or slightly more on the oil as long as that computer says the oil is still good, who are we to argue..keep in mind that this is highway miles from Detroit to El Paso several times around...and they still use the conventional oil and this is a true example

 

 

There is no such thing as too often an oil change as far as the health of the engine is concerned. There is such a thing as too long an interval. But i look at it this way. If somone wants to run Synthetic and do only one oil/filter change every 10,000 miles, thats fine, I just wont buy a car from them. If the car starts burning oil, its their money, not mine.

 

nipper

Link to comment
Share on other sites

  • 1 month later...

hey campers. Just a thought. The military has a program called P.O.L. This isn't my area of expertise. That short for petroleum Oil Lubrication(or cant).

They actually do analysis on the these fluids. Maybe a "full-timer" or fellow Minuteman could shed some light on this issue that may help.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...