I was doing some research on oil recommendations and;
 

I ran across some information on the manner of identifying oil weights, or at least means of classifying weights. It seemed in the early 1990's or their about there was some studies on oil recommendations that specified that the Viscosity Weight of the oil would be redefined to be a recommended minimum weight. For a variety of reasons but much of it due to the emphasis at the time of improving Café fuel economy largely for some (at the time) government edict or another.
While there is an element of truth to improved fuel economy as a function lighter engine oil in the real world it is difficult to measure any relative results. And if any and done incorrectly, engine reliability becomes a serious problem.
Fast forward another 10 years there were additional studies done to ascertain the extent of engine reliability and initial tests using recommended oil viscosities of that time such as the 5W20 Oil early (and maybe all I am not sure) but early Saturns anyway were OEM specified to run. There were unable to establish initially a base line for comparison purposes as engine failures existed to the point where the compression rings were to become stuck in the lands and oil consumption increased drastically with early on engine failure as a direct result.
And low and behold, that is the reputation that early Saturns had.
As this was in part at the time I was chasing things down only a small part of what I was looking for I lost all references to where I was looking at the time. But did note while scanning the information that the early on results of being unable to establish a base line lead to further re-defining of engine oil viscosity not only by definition but by formula also.
There are an awful lot of what I would call a "TOO" light weight oil being specified for use in a variety of climates that range from below zero F or for that matter Zero C too and temperatures of 212F or 100C as multi-weight oils kick in heavier weight characteristics for heavy duty work or working in high temperature ambient environments, but apparently todays oils are better suited for the job then they were in the period of the early 1990's
A lot was said about Multi-(viscosity) vs Mono-(viscosity) as a comparison. It seems that oil technology like everything else has gotten pretty high tech in the last couple of decades. And of course the variations in performance of synthetics and the way's the chemistry of them can be varied.
A whole lot different then when I first started to drive and it was simple. You ran straight 20W detergent during the winter and straight 30W detergent during the summer and detergent vs non-detergent kept the gunk cleaned out of the engine and deposited into the oil filter. In an era where an oil filter was an option on a number of engines.
It was interesting and needs further research to follow the thread a little closer but for the first time I actually read some positive information as to why early Saturns, a vehicle designed wholly by General Motors a company that has been no slouch at the time in designing some of the best cars and engines in the world. Why that engine seemed to go so wrong if the Factory recommended oil was used during it's life time.
And many of us have fed the things at least something like a 10W30 and had wonderful reliability for a minimum of 100,000 miles.
At least mine has been that way.
Of course a lot of sitting has been done lately and I discovered today that the head lights would not open. I think the contacts in the steering column switch have become oxidized and are making poor contact.
Another project for my round tuit list.

Nice write up, Unc. Good luck with the headlights. I hope Val is continuing to improve and recover from her transplant surgery.

My car is one of the last S-series to be made (2002), and the oil cap says 10W30 on it. I suppose I should be feeding it synthetic to get the best protection for such a high mileage engine (200k). But, dino oil has worked just fine, and dino oil is still cheap per bottle. I'll keep feeding it dino oil because it seems happy with it.

Anyone run synthetic? Tangible benefits? Still consuming oil?

consumes less oil but costs more so which one matters more? Neither

As automobiles are my hobby along with a necessity as required by the demands of life I have played "car" for years. And at the moment have a fleet I guess that is genuine overkill.
I have Synthetic oil in my Chrysler (which I just wrecked this week - don't ask!) with 114,000 miles on it and while I think synthetic oils are the premium oils of the era at the moment I do not run them on anything that I did not start out that way with. Running an acceptable weight oil as determined by the Oil weight vs ambient temperature charts seems to give acceptable performance and also did so when I was in charge of a fleet of mixed vehicles run in an environment where triple digit temperatures were often seen. And this was using dinosaur sourced oil. Having run a few engines up into close to 300,00 miles with no problems I personally believe either oil works about the same when regular recommended oil change intervals are followed. And keeping in mind, Mobil 1 which I use is recommended to change the oil filter at a given interval and add the amount of oil lost with the change and there is a recommended mileage interval you change everything and when that is followed the cost of using Synthetics vs dinosaur oil is almost exactly the same.
As I have not had an engine consuming oil since 1976 when I left the snow belt and started living in the SW I agree if consuming oil it costs more to feed an engine synthetics. but I have not had an oil consuming engine (yet).
I am assuming the recommendations of all synthetic oils are similar. And there are a lot more of them then there were when I started using Mobil 1.
Interesting that the last of the SC series engines have a 10W30 oil cap on them. I did not know that.
My Chrysler (a 2007) and my Saturn (a 1994) both have a 5W20 recommendation which I personally have ignored from the day I purchased them.
Now if the insurance people will put my Chrysler back together I will be thrilled. The adjuster will be by today about 10:30. Whoopy-ding. And it is my birthday.

Happy Bday, UNC! Hopefully the adjuster will give you what you want for your birthday.

I think you mean 5W30 not 5W 20 for the 94 Saturn.

Interestingly, the way they achieve the higher viscosity oils today (10W40l and above) involves starting with a lower viscosity base mixture, then tossing in a bunch of additives to ensure the viscosity vs temp behavior is correct for the oil weight in question.

The potential problem is that the additives may begin to break down, esp the ones that maintain desired viscosity at elevated temperatures, leading to you essentially putting in say 20W50 and, as time passes, having it change effectively from a 20W50 to the equivalent of a 10W40 or 10W30 based on the overall usage type and environmental conditions. This is especially true for today's synthetics.

I'm not saying this is universally true today. I'm not saying dino oil behaved that way back in the days before all these additives were developed as the formulations were different and I believe the visc vs temp profiles were obtained differently back then.

I'm just saying it can happen with anything 10W40 and above in today's oil landscape.

This all comes from an article I read about six months ago. I will try to find and post the link.

[QUOTE=derf;52370]Happy Bday, UNC! Hopefully the adjuster will give you what you want for your birthday.

I think you mean 5W30 not 5W 20 for the 94 Saturn.

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Nope I mean 5W20.
Both my Saturn and my 2007 Chrysler clearly states to use 5W20 motor oil on the oil fill cap. And when I bought my Chrysler I went to the optional "take care of your new car" seminar that was offered and when I raised the question of synthetics I was clearly told that would violate the terms of the factory warranty.

So when I got the car home I decided that that violating the warranty was safer than using an oil recommendation that stood the chance of wearing the engine out as it was common pretty much after WWII at 100K oil consumption was about equivalent of that of the alcohol of a drunken sailor (something I was some what accustom to as being a sailor) I immediately changed to oil to 15W50 Mobil 1 synthetic and never bothered to tell them.

And yup the adjuster said the fixing my Chrysler was a financially responsible decision. (Happy dance) and it will go to Bill Luke , the Chrysler dealer where I bought the thing.
Costs will be my 500 deductible and the about $400.00 ticket I got for having the accident.

And oh yuh
Merry Christmas

Derf
I think that from what little I have read recently on oil formulation that there are a number of things going on in the chemistry as to Viscosity is determined both short and long term.
The concept of an average thickness or viscosity as it act and how temperature ranges effect things, cold starts vs hot environments.
And add to that F.I. is pretty much a start and drive mode of operation where a carbureted car needed to be warned up before it ran worth a darn. (A problem when a today's hobbyist restores a carbureted car and then is disappointed in how it runs until it gets warm.
Also you have todays Computer assisted machining which can and does not only hold tighter tolerances part to part but has the capability of manufacturing complex parts that were not available years ago.
For example and just one of them, many if not most engines including all number of cylinders are 2 bolt mains, a 4 bolt main engine is considered unusual and generally applied to heavy duty usage motors racing and performance specifically but todays LS1 Chevy V8 has 6 bolt mains which when assembled makes a pretty tuff block assembly yet that engine in not only a performance engine but found in trucks.
A performance engine in the distant past would or could or did use ball or roller bearing main bearings and the offy 4 cylinder engine the main bearing assembly was installed with an interference fit by heating the block as the crank was installed with the main bearing holders assembled on the crank shaft.

Obviously it was a marvel in precision manufacturing at the time, but it was assembled with an acetylene torch applied to the block to expand the bearing holders so things fit. A production technique not adaptable to mass production.

And todays motors use adjustable cam shaft timing which is a method known for shifting performance rpm around but only when installing a cam leading or trailing a bit. Todays taxi cab motors do that automatically now using oil pressure. A function in part of the viscosity of the oil of course which places new demands on things.

The subject becomes fraught with variables!

I wholly agree that there are many variables that may come into play when trying to evaluate the performance of today's additive rich oils. My comment was directed at the overall outcome of those interacting variables MAY be a significant decrease in oil viscosity (behavior and property wise)/for the higher weight oils vs those oils with less additives.

I am in no way implying that every crankcase full of 20W50 turns into 10W30 in 300 mi. I'm simply pointing out that, based on current formulation techniques, this behavior MAY be seen. You are quite correct in noting that a zillion variables will affect the oil's behavior as a function of time, temperature, etc. I was simply trying to broadly describe a single well known phenomenon that is known to occur.

Happy Belated Birthday, John. Did you go out and party? Get s*%t face drunk and pick up a prostitute? Wait a minute, I'm thinking about goalieo. Never mind. LOL

I found the article, though it is not free for download but can be read at

Stan Toepfer Understanding Motor Oil Viscosity - Documents

The quote most relevant to my statements is

"Advances in petrochemical engineering soon led to the development of chemical additives (viscosity enhancers) which when combined with a motor oil increased it’s viscosity index making it possible for a single oil to meet both the low temperature and the high temperature grade specifications. The molecules of these additives unwind as the temperature of the oil increases and slow down the rate at which the oil’s viscosity decreases. Additive enhanced oils which met both warm and cold temperature specifications became known as multi-grade oils. A major drawback to early multi-grade oils was oxidation of the viscosity enhancers during normal engine operation. As they oxidized they left harmful deposits inside the engine and their ability to maintain viscosity at higher temperatures degraded – simply put they were dirty and they wore out. Subsequent research and development has significantly reduced but not fully eliminated these problems. Development of fully synthetic motor oils has however produced multi-grade oils that do not incorporate viscosity enhancers.These oils are produced by breaking hydrocarbon molecules (typically ethylene gas) apart and recombining the component pieces into oils with entirely new molecular structures. These entirely man-made synthetic oils have extremely high viscosity indices. The downside to synthetic oils is their expense – they are expensive to produce and cost 3X or more as much as conventional oils. That expense is offset somewhat by the fact that they are very clean running and have extended life spans."

So, as I mentioned above, it is not an issue with every 20W-50 oil sitting in a crankcase; but it can and does still happen with the conventional oils. I had forgotten that truly full synthetics with no viscosity modifiers are not affected.

Growing up, devoid of any real automotive interests, I would always see engine oil ads on TV where all he manufacturers were trying to hawk the fact that THEIR oil was the best at withstanding (not preventing) "high temperature/thermal viscosity breakdown."

So THIS is what they were talking about............finally it has come full circle in my mind...

I know, taken as read.

And phenomenon's have been re-defined as time had brought out new information.

In my files (accumulated as a hobbyist) if have one entitled "Practical Lubrication for the Automobile" published by Standard Oil Company of NewYork 26 Broadway featuring the application of SOCONY petroleum Products.
It is a 60 page reference manual that discusses routine care and maintenance of your automobile at the time. Printed in 1923.
The discussions are pretty much in depth and on page 44 begins a 4 page directive on the proper weights of Socony Oils to use in the engines,(Winter and Summer) transmissions and differentials.
The weights of the oils are defines as
LM for light mdium
M for medium
H for heavy
EH for extra Heavy
G for Gear oil
Thus follows and alphabetical list of automobiles ranging from ACE to Winton followed by a listing of Trucks, tractors and boat motors.
One line might read (taken at random) for the Hudson for the year 1922 -1923 uses Medium grade oil in the summer and Light Medium oil in the winter. Where as the recommendation for a Mercer would read Heavy Grade oil for the summer and Medium grade oil for the Winter.
The point simply being a lighter viscosity oil in general was used during the winter and a heavier one during the summer.
A pattern held true to the time in about the 1970's when I was not to many years out of the service and stationed in the south where light grade oils simply were not carried as were things like anti-freeze. There was no need for anti-freeze, it did not get cold enough to use it and the good old boys in the south did not waste money on it. When the cooling system broke down, just fill it up with water.
A fairly good reason why for example, the aluminum engines introduced at the time universally failed. The infrastructure did not exist to supply them with the coolant needed to keep them from rotting out the coolant passages. I know I had that problem after replacing a blown gasket in a French car I owned at the time. As Anti-freeze was not available the radiator plugged solid in 6 months after making a repair on an engine that had an aluminum cylinder head.
Then it was also common to use 20W in the winter and 30 weight during the summer and straight weight, not detergents. Which brought about long discussions as to the benefits of both detergents and multi-weight oils as to the benefits of the extra costs involved in purchasing and using these new technology products.
Products now commonly used and the discussions "the same ones" are applied to the newest of the petroleum products.
Thanks for the reference to the article, now I gotta go read it.

Edited.
Derf
Trying to catch up with reading and taking care of things around the house has been a chore.
Synthetics probably have these characteristics, I don't really know which means I need to read some but putting a time line on things as I see it and I think is fair. Synthetics, while they were developed and used during WWII and maybe earlier, they were used by in large due to lack of having an oil industry for the use of lubrication during the war. My reading pretty much limits them in general to the German developments during that war. I rarely if any see reference to them as applied to other theaters.
As a teenager in the 50's and just learning to drive and take care of a car, even detergent straight weight oils had to develop a popularity due to increased costs of buying them
In addition, there were a number of models of automobiles that an OiL filter was still an extra cost option on the engine. Nash for one comes to mind and I think the I-6 Ford truck I once owned, a 1960 model the oil filter was an option for it. Either that or it was the spin on oil filter was an option. But air filters were either pretty much non-existent or they had strainers in them that kept large bugs out of the carburetor. Oil Filled filters took a while to be replaced by the paper air filter and piston ring wear was big time based in part on materials and in part on poor filtering of dust.
In 1960ish my parents came into the south where I was stationed and were not able to get a 10W30 Multi-weight oil for their car for an oil change prior to going back north during the winter.
Event the assumption that the advantage of multi-weight synthetics are universally used is not really true as at least in 2007 when I bought a New car synthetics were against the warranty requirements of the engine.
One can not assume the advantages if any are not universally used in that dealers are offering (at least the ones I have been at) optional synthetics on their oil changes.
And then as a cost benefit, and that too is real, once a warranty id off the car and in general that time interval is that of a 2nd owner, paying the costs of a synthetic oil vs a petroleum based oil is a function of the economics of the next owner. The dealer or manufacturer no longer holds any claim on warranty service at that point in time.
Granted, oil change interval of synthetics is anywhere from 3 to 5 times longer than a petroleum based oil with the exception of a routine filter change during the service life followed by replacing the oil lost by te filter change. This off setts the costs of the synthetics while not hurting it's performance. It makes using a synthetic oil a cost effective approach.
But not all people subscribe to that.
So many cars today are sold as an appliance rather than something that requires maintenance in order to supply reliable service.
This is of course supported by me anyway in the number of times I have gone on to a dealer lot in the last couple of years and been approached by the friendly salesman offering me a ride in their golf cart to go and choose a car OR they will bring just what I want up to the show room and let me look.
And the salesman in question at the time getting their panties in a knot when asked to see if the features I want are actually on the car they want to show me.
Yuh, things are changing and when technology is applied will, but even back in the day, Heavier oil weights were recommended for summer use vs lighter weights for winter and multi-viscosity oils might not be all that multi-in the long run. But in many cases, the recommended oil change interval was modified so that those variations as a function of time and use were not a significant factor in anything.