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Unregistered
05-23-2004, 09:34 PM
does age affect synthetics (mobile 1) less than petro-based oils? I drive the 525 only on weekends...seems futile to change oil every 1000 miles, which is about what I do in 3 mos. can I go 6 months or more?

Craig
05-24-2004, 01:16 AM
I wouldn't worry. Do it every 6 months, just make sure you get the oil good and hot when you do drive the car and you will be fine.

MBXB
05-24-2004, 03:13 AM
Here's a study on synthetic oil change intervals"

http://neptune.spacebears.com/cars/stories/oil-life.html

Hector
05-24-2004, 09:35 AM
a red flag for me is that the study uses low mileage cars. If they used synthetics in cars of 100k and even 150k+, I wonder what their results would be.

George M
05-24-2004, 10:10 AM
don't think it matter that much...downside of using higher mileage cars is they tend to consume more oil and hence would taint results because clean oil is added to the car's sump over time which reduces metal traces. For testing purposes, best to use an engine that does not consume much oil. Other thing is this study does not address the poster's initial question and that is the influence of time versus mileage. This study is performed within a relatively short time frame and does not speak to leaving synthetic in for a long period of time with low mileage use. I too face the same situation...long time period oil change intervals due to low mileage use.
George

Hilly
05-24-2004, 10:43 AM
Another consideration is that higher mileage cars tend to produce more blowby into the crankcase, therefore contaminating and diluting the oil faster.

I have been using mobile 1 in my last two 5ers.....both high mileage. I would't change the oil any sooner than 6 to 9 month depending on the time of year. The more stabile, drier and warmer the weather, the longer you can go.

Oh and that 0-40 Mobile 1 is all I use now.... If you hate your car use Pennzoil..

George M
05-24-2004, 11:12 AM
ditto...also shorter duration driving adds a lot of condensation to the oil resulting in need for more frequent change intervals. Not sure if Pennzoil is so bad for dino oil.
George/ Mobil 1 fan

Unregistered
05-24-2004, 11:38 AM
does age affect synthetics (mobile 1) less than petro-based oils? I drive the 525 only on weekends...seems futile to change oil every 1000 miles, which is about what I do in 3 mos. can I go 6 months or more?

General rule is change your oil at least once a year. Given you are only driving approximately 4000 miles a year, you may want to consider using dino oil changed once a year, barring you are running lapping days or driving the car in -20F weather. Chevron, Pennzoil (yes Pennzoil, the old sludge problems are history), and Castrol all make good mineral oils. Choose the appropriate weight for your temperatures based on the factory manual recommendations.

Cary

ryan roopnarine
05-24-2004, 11:56 AM
the people at bobistheoilguy.com have three favorite conventional cheap oils: pennzoil (despite what has been said about it in the past), chevron supreme, and castrol regular. i wouldn't believe the claims about pennzoil being a good oil until i had read some of the oil analyses over there done on pennzoil.

Hector
05-24-2004, 12:02 PM
My point still stands. I understand you need lower mileage vehicles to get more reliable results; reduced contamination, oil consumption... but in our high mileage cars, the frequency of oil change would be higher than, say, a 30k mile car. So to answer the question in the original post, the age of oil would certainly depend on the mileage of the car. Whether you have synthetic or mineral-based oil, the same applies to both. Right?

632 Regal
05-24-2004, 12:17 PM
I don't think that the added condensation would make a bit of difference on the oil, after it gets hot enough to get the steam out than all thats left is the original oil. Now, if you try that with dino oil you will get an enormous amount of sludge buildup because the condensate will merge with the oil leaving waxy sludge deposits on everything that is not constantly bathed in oil.


ditto...also shorter duration driving adds a lot of condensation to the oil resulting in need for more frequent change intervals. Not sure if Pennzoil is so bad for dino oil.
George/ Mobil 1 fan

632 Regal
05-24-2004, 12:22 PM
simple question simple answer..Yes

George M
05-24-2004, 12:43 PM
maybe you are right Jeff. The surprising result from the study is how the viscosity of Mobil 1 increases over time/with accumulated mileage. Again...still doesn't address the original posters question. An example is...Mobil 1 unused may have a shelf life of 5 years...perhaps longer. Say you drive your car 1k a year, Mobil 1 may be fine in your crankcase for a couple if not three years. Would like to see empirical findings on that.
Don't believe the old benchmark of changing dino oil every year is necessarily applicable to low mileage accumulation using for Mobil 1...but might be.
George

ryan roopnarine
05-24-2004, 01:01 PM
lemme go ahead and throw some more fuel on this fire with this

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

also from paradise garage. it seems that the most accurate method that they found involves determing the oil consumption amounts (using mobil 1). gonna play with it for a few minutes now....

Unregistered
05-24-2004, 01:41 PM
the people at bobistheoilguy.com have three favorite conventional cheap oils: pennzoil (despite what has been said about it in the past), chevron supreme, and castrol regular. i wouldn't believe the claims about pennzoil being a good oil until i had read some of the oil analyses over there done on pennzoil.

If you check the UOA section of Bobistheoilguy you will find some good UOA on Pennzoil.

Back to the Original Question. Generally, Synthetic can be run for longer change intervals than Mineral Oil. However, as other members have mentioned, oil gets contaminated over time, and given how little you are driving, you are likely killing the oil from contamination over time rather than using up the additive package from combustion byproducts.

The once a year maximum I cited is generaly for both minerals and synthetics. So given that you are only driving 300-4000 miles a year, the benifit of longer change intervals with synthetics (7500 miles+) v. 4000-5000 miles of mineral would not be reconized. For your situation, Mineral would be the most cost effective solution, changed at one year intervals ( or six months if you want to be anal). You could run synthetic but there is no advantage in your case.

Cary

MicahO
05-24-2004, 02:13 PM
lemme go ahead and throw some more fuel on this fire with this

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

also from paradise garage. it seems that the most accurate method that they found involves determing the oil consumption amounts (using mobil 1). gonna play with it for a few minutes now....

I like the calculation methods, particularly because they a)provide proof that the 15000 mile recommended interval on my car is dead crazy, and b) back up my suspicion that oil changes in the 7500 mile range are properly targeted when using Mobil1.

Nice link!

ryan roopnarine
05-24-2004, 02:31 PM
the shortcoming they note for the sixth method is significant, though. changing between .5 and 1 quart consumed per 6k miles drastically alters the estimates. for my particular engine, i calculated the specific coefficient using 3.31 bore, 6cyl and 10 compression, and then put it in. i used the 15.5 TBN of the mobil1 5w30 given in their study in the camaro as the starting point, and put the end number at 4, which was way below the 18k level for that oil. i did both because i've never ran this car on mobil 1 5w30 before now, and my current usage is high because bg44k has been in the oil for at least 3k miles now. by switching between .5 and 1, i got 6629 and 7231 miles, respectively. too bad money is a little tight, das kar is probably going to get 6 quarts of free maxlife 10w30 for its next oil change in 700 miles.





I like the calculation methods, particularly because they a)provide proof that the 15000 mile recommended interval on my car is dead crazy, and b) back up my suspicion that oil changes in the 7500 mile range are properly targeted when using Mobil1.

Nice link!

Unregistered
05-24-2004, 03:00 PM
I like the calculation methods, particularly because they a)provide proof that the 15000 mile recommended interval on my car is dead crazy, and b) back up my suspicion that oil changes in the 7500 mile range are properly targeted when using Mobil1.

Nice link!

I think you are spot on. Without doing a UOA, 7500 is a good oil change interval. BTW, on Bobistheoilguy there are some UOA's of BMW synth pushed the full change interval of 13,000-15,000 miles. Basically, the oil showed being in use a few thousand miles two long and the wear numbers show the spike you expect once the additive package has been depleted.

On a seperate, non scientific note, I was speaking with my mechanic on Friday and he told me that they recommend to customers that they change the oil every 7500 (they use factory 5w-30 BMW Synthetic (castrol group III)) which almost perfectly splits the service interval. He commented that on the cars that do not follow this advice and go the long interval, the valvtrains sound like they are full of marbles at 100,000 miles.

Cary

George M
05-24-2004, 03:23 PM
Cary, the benefit of synthetic isn't about what you coin exhausting the additive package from combustion by-products or time/mileage to oil breakdown that is superior with synthetics that allow them to be used longer...it is about long term wear to the engine due to the superior lubricity of synthetic oil. Your thesis that if running few miles per year one should use dino versus synthetic is incorrect if you want to optimize engine life. Even if mileage accrual is slow, if one compares an engine using dino versus an identical engine using synthetic, the engine using synthetic oil will yield superior wear resistance over time. Your comment that engines that aren't run much should be run on dino just doesn't hold up if the objective is to optimize engine life. Why I run Mobil 1 in my car that only sees less than five thousand miles per year.
George

Unregistered
05-24-2004, 05:14 PM
Cary, the benefit of synthetic isn't about what you coin exhausting the additive package from combustion by-products or time/mileage to oil breakdown that is superior with synthetics that allow them to be used longer...it is about long term wear to the engine due to the superior lubricity of synthetic oil. Your thesis that if running few miles per year one should use dino versus synthetic is incorrect if you want to optimize engine life. Even if mileage accrual is slow, if one compares an engine using dino versus an identical engine using synthetic, the engine using synthetic oil will yield superior wear resistance over time. Your comment that engines that aren't run much should be run on dino just doesn't hold up if the objective is to optimize engine life. Why I run Mobil 1 in my car that only sees less than five thousand miles per year.
George

Well your belief runs directly contrary to the hundreds of Used Oil Analysis that I have seen on Bobistheoilguy. Bottom line is that synthetic oils do not have some magical properties that give them superior lubricity, they are merely a more homoginous oil that accordingly needs less VI improvers to meet weight requirements, and don't break down as quickly.

I would recommend that you start sifting through the used oil analysis on bobistheoilguy. Just for fun I posted links to a few. Notice the first three are mineral oils and numbers 4-5 are BMW Synthetic oil. Kind of funny but the wear numbers are virtually the same and these are from the same type of engine (M50). Run the oils to 7500 or 10,000 and you will start to see some changes as better quality synthetics (i.e. Mobil 1, Amsoil which are both Group IV v. BMW Group III hydrocracked oil) keep low wear numbers (see number 6 link which Is German Castrol a Group IV/V blend oil) and the lower wear numbers v. the BMW oil (look at lead, copper and iron).

As a final note, even Redline's Roy Howe has admitted that synthetic oil in most cases will do nothing to improve engine life. As you are so certain that an engine that sees few miles will last longer on Synthetic could you please share the data that you have to support this belief? Or would it be that you were merely speculating when you denounced my "thesis" which is based upon hard data?

Cary

http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=3;t=000354#000000

http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=3;t=000467#000000

http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=3;t=001294#000000

http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=3;t=000754#000000

http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=3;t=001176#000000


http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=3;t=001401#000000

Hector
05-24-2004, 05:55 PM
The fact that synthetics are more homogeneous than mineral oil is indeed a property of the oil. I didn't have the time to go back and forth with you a few weeks ago when this subject come up in a thread that you told me synthetics do not have "superior antiwear properties." Again the fact that it's viscosity is more homogeneous over a wider temp range than mineral oil implies that the engine will enjoy increased life spam due to this property. Now if people are contracting this due to some tests, that is a different story and perhaps Mobil 1 and other synthetic affiliates marketed a major propaganda hoax???!!!! Something is wrong with this picture.


Well your belief runs directly contrary to the hundreds of Used Oil Analysis that I have seen on Bobistheoilguy. Bottom line is that synthetic oils do not have some magical properties that give them superior lubricity, they are merely a more homoginous oil that accordingly needs less VI improvers to meet weight requirements, and don't break down as quickly.

I would recommend that you start sifting through the used oil analysis on bobistheoilguy. Just for fun I posted links to a few. Notice the first three are mineral oils and numbers 4-5 are BMW Synthetic oil. Kind of funny but the wear numbers are virtually the same and these are from the same type of engine (M50). Run the oils to 7500 or 10,000 and you will start to see some changes as better quality synthetics (i.e. Mobil 1, Amsoil which are both Group IV v. BMW Group III hydrocracked oil) keep low wear numbers (see number 6 link which Is German Castrol a Group IV/V blend oil) and the lower wear numbers v. the BMW oil (look at lead, copper and iron).

As a final note, even Redline's Roy Howe has admitted that synthetic oil in most cases will do nothing to improve engine life. As you are so certain that an engine that sees few miles will last longer on Synthetic could you please share the data that you have to support this belief? Or would it be that you were merely speculating when you denounced my "thesis" which is based upon hard data?

Cary

http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=3;t=000354#000000

http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=3;t=000467#000000

http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=3;t=001294#000000

http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=3;t=000754#000000

http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=3;t=001176#000000


http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=3;t=001401#000000

Unregistered
05-24-2004, 06:25 PM
The fact that synthetics are more homogeneous than mineral oil is indeed a property of the oil. I didn't have the time to go back and forth with you a few weeks ago when this subject come up in a thread that you told me synthetics do not have "superior antiwear properties." Again the fact that it's viscosity is more homogeneous over a wider temp range than mineral oil implies that the engine will enjoy increased life spam due to this property. Now if people are contracting this due to some tests, that is a different story and perhaps Mobil 1 and other synthetic affiliates marketed a major propaganda hoax???!!!! Something is wrong with this picture.

You need to split out 1) engine life and 2) oil life. Synthetics, in and of themselves do not lessen wear on engines. Synthetics are more stable over a wider tempurature range and require less VI improvers, the result of which is they last longer.

The primary benifits of Synthetics are:

1) Better cold tempurature pumping,
2) Less likely to break down under extremely high temps due to less VI improvers (potentially forming sludge), and
3) Longer life before breakdown and the additive package gives up the ghost.

If you look at the longer change intervals by auto manufactures you will notice that they require synthetic oil, for the exact reason that it lasts longer. Mercedes was actually sued for not specifiying this in the late 1990's as they had cars going 11,000-12,000 miles on mineral oil and it was sludging up and killing motors.

Does a Used Oil Analysis tell us everything about a motor. No. But it does give us objective data in measuring how fast an engine is wearing. You have to be careful though becasue different engine designs and manufactures have different wear characteristics. Here I have posted UOA's of oils all used in M50 (few M52) BMW engines, some of which come from the same motor. As is expected, the wear numbers from the (good) mineral oils and synthetics are very similar at lower milage. Push the mineral oils to 7500 or 10,000 miles and you will start to see the Synthetics pull ahead.

Also note, that this relates to normally driven cars, track cars with 280F sump temps, turbo cars, etc., do benifit from the extra stability of synthetics.

Finally, for the record, I use Mobil 1 0w-40 in all my vehicles. I believe it is a great oil and change it out at 7500-8000 mile intervals. However, if you have a weekend car that goes 4000 miles a year and you drive it moderately, using Mobil 1 is a waste of money. Changing Mobil 1 at 3000 mile intervals is also a waste of money. The benifit is from having low wear over longer change intervals and added protection, not to mention that less waste is created (not that I am a tree hugger or anything).

Cary

632 Regal
05-24-2004, 07:00 PM
After all of this studying and comparing of different wear properties and all the other crap that Bob is saying, I will simply stick my foot in the ground and heave a message that no matter what Bob says I'm sticking with my synthetic Mobil stuff. You can use whatever you want in your 300-4000 a year engine but I will use what I chose back in the early 90s and havent had ANY oil/sludge problems since in any engine I built or run.

mann my spelling sucks today.

ryan roopnarine
05-24-2004, 07:08 PM
one thing i "found" thinking about this


http://www.blackstone-labs.com/faq.html

which is by one of the more "popular" oil analysis companies. this particular graph seems to refer to people having concerns about high levels of wear in analysis of seldom-driven automobiles

"I haven't even used this engine in six months. Why is wear high?

The old adage is still true: use it or lose it. Inactive engines tend to build up moisture on the inside. That moisture causes corrosion, and when the engine is started up, all that corrosion is scraped off into the oil. We suggest frequent oil changes after a period of engine inactivity, to reduce the abrasiveness of the oil."



"

Unregistered
05-24-2004, 07:09 PM
After all of this studying and comparing of different wear properties and all the other crap that Bob is saying, I will simply stick my foot in the ground and heave a message that no matter what Bob says I'm sticking with my synthetic Mobil stuff. You can use whatever you want in your 300-4000 a year engine but I will use what I chose back in the early 90s and havent had ANY oil/sludge problems since in any engine I built or run.

mann my spelling sucks today.

You spelled Mobil properly which is more than I can say for many people!!!!! You will never go wrong with Mobil 1, the only question is if there is a benifit if you change the oil every 3000-5000 over mineral. One other thing to keep in mind is Mineral oils have improved considerably in the past 10-15 years with much better base stocks (Chevron & Pennzoil both use Group II+ basestocks which are much better than the old Group I stocks that were widely used).

Hector
05-24-2004, 07:28 PM
specifically for my m30. I too do not drive (when it is up and running, of course) often, and when I do, the car is driven on weekends. I have noticed increased oil consumption and always wondered if it was due to poor lubrication at cold start from being parked for weeks. After the car is fixed, I intend to drive the car at a minimum of once a day even if it's around the block. I already got too much invested in this vehicle to let it go down the toilet because it hasn't been driven enough.


one thing i "found" thinking about this


http://www.blackstone-labs.com/faq.html

which is by one of the more "popular" oil analysis companies. this particular graph seems to refer to people having concerns about high levels of wear in analysis of seldom-driven automobiles

"I haven't even used this engine in six months. Why is wear high?

The old adage is still true: use it or lose it. Inactive engines tend to build up moisture on the inside. That moisture causes corrosion, and when the engine is started up, all that corrosion is scraped off into the oil. We suggest frequent oil changes after a period of engine inactivity, to reduce the abrasiveness of the oil."



"

Unregistered
05-25-2004, 09:57 AM
specifically for my m30. I too do not drive (when it is up and running, of course) often, and when I do, the car is driven on weekends. I have noticed increased oil consumption and always wondered if it was due to poor lubrication at cold start from being parked for weeks. After the car is fixed, I intend to drive the car at a minimum of once a day even if it's around the block. I already got too much invested in this vehicle to let it go down the toilet because it hasn't been driven enough.

I would suggest that you don't worry about driving it every day, but instead focus on making sure that at least once a week or every other week that you drive the car at least 20 miles at one time. The idea is that you want to get the oil up to operating tempurature (which suprisingly takes a long time, 5-10 minutes in moderate weather) and keep it there for a while to burn off the contaminents and moisture in the engine. Simply driving it around the block will not do this and will merely result in multiple cold starts where the car is run for to short of a time to get the engine and exhaust up to operating tempurature.

Cary

Hector
05-25-2004, 10:49 AM
Actually, I don't know why I said what I said because I'm well aware that frequent cold starts and frequent short trips contribute to condensation. I even mentioned these points in a post a couple of weeks ago. Most of been a case of the Mondays...


I would suggest that you don't worry about driving it every day, but instead focus on making sure that at least once a week or every other week that you drive the car at least 20 miles at one time. The idea is that you want to get the oil up to operating tempurature (which suprisingly takes a long time, 5-10 minutes in moderate weather) and keep it there for a while to burn off the contaminents and moisture in the engine. Simply driving it around the block will not do this and will merely result in multiple cold starts where the car is run for to short of a time to get the engine and exhaust up to operating tempurature.

Cary

George M
05-25-2004, 12:26 PM
I too appreciate all the input you have provided Cary including all the links you have referenced. And would say I have to agree with much you have written as you are well informed on the subject. I do believe however that Mobil 1 and even more so Amsoil synthetic, depending on which less than blind study you read is more slippery than conventional motor oil. It just stands to reason that a man made substance could be formulated at a cost premium to provide better wear resistance than petroleum substrate oils which use additives to enhance wear resistance. I cannot produce anything better than anecdotal evidence that this is the case however and am unwilling to put forth the effort to provide good corroborating scholarship on the subject due to time. I will continue to use a synthetic like Mobil 1 in my M-30 engine just like every other racing team on the planet be it a drag racing top fuel car or Formula 1 car...independent of sponsorship that use synthetic because it does increase horsepower incrementally due to its superior lubrication and where its beneficial non-Neutonian temp/viscosity relationship, anti-sludging properties etc isn't as high a priority but does optimize a street car engine durability over time.
Do appreciate your comments.
George

Bill R.
05-25-2004, 12:34 PM
mile test... I thought that was pretty conclusive and I haven't seen any dino oils come forward with similar test results...








I too appreciate all the input you have provided Cary including all the links you have referenced. And would say I have to agree with much you have written as you are well informed on the subject. I do believe however that Mobil 1 and even more so Amsoil synthetic, depending on which less than blind study you read is more slippery than conventional motor oil. It just stands to reason that a man made substance could be formulated at a cost premium to provide better wear resistance than petroleum substrate oils which use additives to enhance wear resistance. I cannot produce anything better than anecdotal evidence that this is the case however and am unwilling to put forth the effort to provide good corroborating scholarship on the subject due to time. I will continue to use a synthetic like Mobil 1 in my M-30 engine just like every other racing team on the planet be it a drag racing top fuel car or Formula 1 car...independent of sponsorship that use synthetic because it does increase horsepower incrementally due to its superior lubrication and where its beneficial non-Neutonian temp/viscosity relationship, anti-sludging properties etc isn't as high a priority but does optimize a street car engine durability over time.
Do appreciate your comments.
George

George M
05-25-2004, 12:45 PM
Thanks Bill...didn't forget it just deliberately didn't mention it because I don't believe it was performed by an independent/unbiased house. As I recall the test was performed by Mobil 1...lol. I do agree however it is an extraordinary accomplishment and would be quite surprised if the same could be achieved on dino oil.
George

Hector
05-25-2004, 12:53 PM
if one uses an oil that is more stable and therefore has longer life than others, then wouldn't the car piggy-back ride from this property/benefit? Essentially, one can conclude that longer oil life prolongs engine life. Shorter life, shortens the life of the engine--a collorary that's sound to me.




does age affect synthetics (mobile 1) less than petro-based oils? I drive the 525 only on weekends...seems futile to change oil every 1000 miles, which is about what I do in 3 mos. can I go 6 months or more?

Bill R.
05-25-2004, 12:53 PM
oils but they don't tell you that the 90 model was a 3 series bmw just and they do compare wear on conventional oil and mobil one oil here for 200k miles...
(http://www.mobil1-30thanniversary.com/corporate/files/corporate/mobil_1_fact_sheet.pdf)









Thanks Bill...didn't forget it just deliberately didn't mention it because I don't believe it was performed by an independent/unbiased house. As I recall the test was performed by Mobil 1...lol. I do agree however it is an extraordinary accomplishment and would be quite surprised if the same could be achieved on dino oil.
George

George M
05-25-2004, 01:03 PM
Good stuff.

Unregistered
05-25-2004, 03:28 PM
if one uses an oil that is more stable and therefore has longer life than others, then wouldn't the car piggy-back ride from this property/benefit? Essentially, one can conclude that longer oil life prolongs engine life. Shorter life, shortens the life of the engine--a collorary that's sound to me.

In short, no. Both oils cause the same amount of wear, up to the point (about 4000-7500 miles in a M50 motor) that the Mineral oil uses up its additive package. At that point the Synthetic with its better basestocks which allow for a longer life additive package will cause less wear. It is this reason that if you are changing the oil every 3000 miles, there is no point in synthetics. Start pushing the change interval past 5000 miles and you see the advantages.

Now the thought will occur to many, so why not change the oil every 1000 miles for longest life. The strange thing is that oils turn in the lowest wear levels right before the additive package runs out. If you look at the 3mp spacebears study (with 1000 mile intervals) as well as those running Amsoil for long (15,000 mile) intervals, you will notice the number of particles per million are very low on a per 1,000 mile basis. In the case of the spacebears study you will see the initial wear followed by low wear until the addtive package gives up (drop in TBN). Most of the wear occurs in the first 2000-3000 miles.

Some of this is counterintuitative, and it took me years of searching to get these answers. The problem (as many know) is there is a lot of speculation, but very little objective evidence.

Once again to be clear:

1) I avocate the use of Synthetic because there are advantages. I personally feel that Mobil 1 is the best widely available synthetic, with the 0w-40 being appropriate for BMW's in all climates (exclusing the M3 motors that spec Castrol TWS 10w-60).
2) I would always use synthetic in a track car, turbocharged car, or other car that is hard on oil.
3) I question the use and benifit of synthetic on cars that are driven low miles and in moderate climates where the oil will be changed at low miles (3000-4000 miles).

Unregistered
05-25-2004, 03:36 PM
Thanks Bill...didn't forget it just deliberately didn't mention it because I don't believe it was performed by an independent/unbiased house. As I recall the test was performed by Mobil 1...lol. I do agree however it is an extraordinary accomplishment and would be quite surprised if the same could be achieved on dino oil.
George

Couple of notes on the Mobil 1 Test:

1) It was run on a test bench (chasis dyno) and the engine was run constantly (hence no cold starts and running the engine without oil).
2) Note they did not run an identical car with conventional oil.
3) At 7500 mile intervals, you will start seeing the benifits of Synthetics in wear numbers.
4) This is a M20 engine we are talking about, commonly known to go 300,000-400,000 with proper maintence and regular mineral oil changes. Note in the real world the number of cold starts, short trips etc.

For the 200,000 mile test it is interesting they did not note an oil change interval. 10,000 miles, 15,000 miles? I would expect with longer intervals for the motor to perform better.

Note that I just did a tuneup on my Sister in Laws 1989 525i with 206,000. According to the records it has lived its life in Southern California on 20w-50 Castrol and Kendall. There was not a hint of sludge in the head, only the slight yellow-brown oil patina.

Cary

Unregistered
05-25-2004, 03:53 PM
Just thought I would post this here, it is a post by a guy named Terry Dyson who's occupation is oil testing and analysis. It was in response to post on bobistheoilguy concerning the validity of Synthetic Claims.

Please listen up:

I have been testing oil for a long time and right now ( about to change a bit with SM in Fall) with the current PCMO chemistries on the market the average car owner can use a average quality $1 qt SL rated oil, treat it properly with LubeControl and use Fuel Power to keep top end clean, periodically clean engine with Auto-RX and get the same cleanliness and performance you will see using "high end" synthetics. Up to 10,000 miles using at least an annual analysis to avoid and predict problems.

If you run a high performance engine or beat the fire out of the engine then the additional thermal stability of a "syn" may be beneficial. A well added syn is hard to beat. For the average Joe it may be overkill.

5 years ago I could not have said this from an analysis perspective, hydrocracking and new non organometallic adds have changed the whole scene.

The extended drain capabilities of a Syn are unmatched but I can put a blend using Auto- RX and LC right up against about any syn made for the same interval cheaper with same or lower wear rates since I can moderate oxidative rates and development in the host oil.


If you are using a motor oil that is well additized and has a primary group II or higher base, and don't mind spending pennies a ounce for LC/FP and a annual Auto-RX cleaning then you MAY be wasting money on "synthetics".

The distinction is being lost in the realities of chemistry and the ability of formulators to procure efficiencies in high performance syn adds and base oils at lower costs.

GC 0w-30 may be the first real US introduced near syn that has such capabilites, of course castrol charges like it is Redline !

For Max performance or sinfully long drains in a hot running engine then RoyaL Purple, Amsoil, Redline,NEO,and others are smart.

Use analysis to find out what works for you.
Save fuel and money by using appropriate technology for your needs, leave the marketing claims to the other enthusiast boards.

Terry

Bill R.
05-25-2004, 04:30 PM
500k was done on a test track with teams of drivers and it was stopped and started to change drivers and for routine maintenance..And from the pictures that they had of the teardown I recall that it was an m50 motor not an m20.. i'm pretty sure that it had 4 valve combustion chambers. I'll try to locate a copy of the original article that had the pics and measurements for wear on it. And since this was a rather spendy experiment in the first place why would mobil have bothered to run an identical test on conventional oil.. At the time they were interested in how much wear actually took place running synthetic. And for what its worth i rarely see sludge buildup on any modern day cars... I attribute this to more precise temperature control, fuel injection, improved crankcase ventilation systems and more precise mixture control brought on by emission controls and better oils than I saw in the 60s and 70's.. In the 70's it was rare to tear down a 100k engine and not see a lot of sludge.








Couple of notes on the Mobil 1 Test:

1) It was run on a test bench (chasis dyno) and the engine was run constantly (hence no cold starts and running the engine without oil).
2) Note they did not run an identical car with conventional oil.
3) At 7500 mile intervals, you will start seeing the benifits of Synthetics in wear numbers.
4) This is a M20 engine we are talking about, commonly known to go 300,000-400,000 with proper maintence and regular mineral oil changes. Note in the real world the number of cold starts, short trips etc.

For the 200,000 mile test it is interesting they did not note an oil change interval. 10,000 miles, 15,000 miles? I would expect with longer intervals for the motor to perform better.

Note that I just did a tuneup on my Sister in Laws 1989 525i with 206,000. According to the records it has lived its life in Southern California on 20w-50 Castrol and Kendall. There was not a hint of sludge in the head, only the slight yellow-brown oil patina.

Cary

Unregistered
05-25-2004, 04:43 PM
500k was done on a test track with teams of drivers and it was stopped and started to change drivers and for routine maintenance..And from the pictures that they had of the teardown I recall that it was an m50 motor not an m20.. i'm pretty sure that it had 4 valve combustion chambers. I'll try to locate a copy of the original article that had the pics and measurements for wear on it. And since this was a rather spendy experiment in the first place why would mobil have bothered to run an identical test on conventional oil.. At the time they were interested in how much wear actually took place running synthetic. And for what its worth i rarely see sludge buildup on any modern day cars... I attribute this to more precise temperature control, fuel injection, improved crankcase ventilation systems and more precise mixture control brought on by emission controls and better oils than I saw in the 60s and 70's.. In the 70's it was rare to tear down a 100k engine and not see a lot of sludge.

The car was definetely an E30 with a M20 motor, I remember the article in Roundel years ago. Why would they run another car on Mineral oil? So they could have a control car. The oil did a great job, but without a control vehicle we don't know if was better than mineral. It is kind of like saying that a performance chip makes a car faster without ever testing a stock car. How do you know?

Cary