derf
You ask my thoughts and then condemn me for giving them?
For shame
Here is the basic thought

Quote
But don't you run the risk of Viscosity Improving Additives breaking down, leaving you running a much thinner oil than you think you are (as a function of time)?
UNQUOTE

There is no risk as long as what you are running is adequate enough to protect the engine.
A Viscosity vs ambient temperature chart simplicity does not address the risk.
An oil selected using has proven to be adequate to get the job done
Therefore there is no risk.

Is it an interesting article absolutely and is probably one of many that cover the formulation of oils for automotive or internal combustion engine usage but it does not factor as a risk.

The example of the Saturn S engine going into failure mode and wearing out using a steady diet of 5W20 oil has been covered over and over again in this forum.
And yet when those reported using a 10W30 oil or greater the wear did not take place.
An inexact comparison but a comparison non the less.
That selection again based on the use of a Viscosity Vs Temperature chart as was the standard apparently at the time and has been and is still being generated does not address the chemistry involved in variations of oil, just the viscosity as stated.
Thus the "Risk" is non-issue.
And unless the need for analysis based on the use of the engine is of a critical importance than the "Risk" remains a non issue.
And that is what I refer to.
As to the interest of the article it is very interesting and no where did I imply it wasn't. Just that the risk implied does not exist.
Although it may have a factor in newer engine application as to how or why to explain there are now published lists of vehicles using factory recommended light weight oils that the owners of them are reporting excessive oil consumption.
And wondering why!

 

Unc,

I have always valued your thoughts; that is why i posted the article in this thread.

I did not condemn your thoughts. I don't believe I condemned anything. You are entitled to your opinion and I am entitled to mine.

What I was less than pleased with was the manner in which you tried to imply that the information in the article was somehow both overcomplicating the oil selection process AND yet not "important enough" to consider at the same time.

Now, you are stating (if I understand it correctly) that because no negative
effects are seen in terms of oil burning or blown engines, there must be no risk. That dos not seem like sound logic to me.

Nowhere was it implied that thicker oil doesn't provide improved lubrication.
Nowhere was it implied that the viscosity vs temp chart was not relevant; it is and continues to be the foundation of oil selection.

All I did was post something informational.

Your thoughts are held in high esteem on this forum, and rightfully so.
What I did not expect nor care for was the implication that somehow posting the information was attacking the entire oil selection process to the point you felt compelled to defend the visc vs temp chart. The article never challenged it....

Now to say there is no risk simply because żou haven't seen a rod punch the block is not terribly logical to me.
The risk exists. Sure, if you run a heavy enough oil, the breakdown that IS occurring may not be severe enough to affect the lubrication requirements at hand. However, in certain applications it may be critical.


Everything does not have to be black and white.

Your choice to view it from your perspective is your right.
My choice to DISAGREE WITH (which is NOT condemnation) your thoughts is my right.

I think it's time for a beer.........
By the way, how's Val doing?

 

To Continue,
Based on recent information that there are a number of manufacturers that are now identified as using oil, something relatively new in the industry since oil consumption was almost totally eliminated after WWII due probably to metallurgy improvements in rings and some sophisticated air cleaners that filtered out a lot of stuff.
Oil use went from single weighs to multi-viscosity but were approximant equivalents.
I've now owned my Dodge Caravan about 3/4 of the way through it's oil change interval of about 4000 miles per change. Using Mobil 1 oil at a 10W30 weight, which the container states a useful guarantee of 15,000 miles, thus an oil filter change every 4, add a quart of oil and continue and I choose to a full change mileage of 12,000 miles.
The thing was down a quart at 3000 miles.
The Chrysler 3.6 V6 engine is on the list of oil consumers.
As a direct comparison to my no deceased 2007 with the corporate 3.3 L V6, the Dodge is about twice the HP and has a 6,500 rpm redline with a 6 speed automatic vs the 3 speed automatic of the Chrysler.
It also is electronic shifted and comparable to the automatic in a way to my Saturn which was also electronic shifted, both have a lock up type torque converter and an operator selected performance/economy mode. In performance mode it will wind out to a quite high rpm between shifts and down shift quickly. As compared to the Saturn it did not twist as tight but in economy mode they both split shift and started out in higher gears.
The Dodge to me at this point in time is showing me that it tends to use oil where as the old 3.3, never used a drop between oil changes also using Mobil 1, but of a 20W40 weight.

 

I am 3500 miles into the first synthetic oil change interval and it has used it's second quart of oil
Despite the reference to use 5W20 Motor oil, I am using Mobil 1 10W30. The vehicle is a 2015 Dodge Grand Caravan with the 3.5L Engine. According to information on the web, that is about the correct oil consumption for the engine.
My 3.3L 2007 Chrysler T&C used no oil between oil change intervals. I guess something must be an improved design.

 

Looks like your new van has the Pentastar v-6 at 3.6 liters. We are having problems with some of our 2015 Pentastar powered Ram 1500 pickups. At about 16,000 miles the are developing a misfire on #5 at idle in gear. It is internal in the valvetrain, the dealer is replacing a cam follower and a lifter plus gaskets. We run semi-synthetic 5w20 Kendall oil in our variable cam timing engines. There must be a tsb from Dodge about this, our dealer repaired it quickly and the parts were readily available. Our second failure showed up late last week. I haven't noticed any oil consumption issues, we change oil at 4K mile intervals.

 

The early Mobil 1 bottles indicated that one could change the filter every 4000 miles and do an oil change at roughly 4 times that interval. Now that seems to be a criteria restricted to the optional long life oil. There are websites tracking cars with oil consumption problems and the lists are rather long. The MOPAR 3.6 is on the list.
The use of a 5W20 has historically been linked to a winter grade oil used below freezing yet now is being recommended in pretty much everything. Yet it seems to be directly the cause of the S series Saturn motors excessive oil consumption and failure by about 100,000 miles. This has been reported frequently as time has passed in this forum. Where as those of us who chose to use a heavier weight oil have had phenomenal reliability if those cars, myself included. That though becomes extremely hard to track and verify as in general by 100,000 miles the vehicle might very well be with it's 3rd or 4th owner and also under minimum care.
The only failure I have had on the 3.6 motor and I am now approaching 32,000 miles is the loss of a coil on and I forget which spark plug, but a coil, spark plug and wire was supposedly replaced. The engine runs well, the transmission seems to work well and I am not getting erroneous error codes from the cam positioning due to the 10W30 motor oil.
But Frankly in 100+ degree temperature I find it hard to accept that the proper weight oil to use is one that historically is tied to a Winter operating condition.

 

As a fleet operator we use 5/20 in the variable cam timing engines and 15/40 in everything else. We service our trucks at 4000 miles or 200 hours on the Fords, 4000 miles is usually 350 hours on our Internationals. The pickups get 4000 miles regardless of hours. We have a no idle policy, but the bucket trucks need to run for the boom to work. If we were in the area of the country that you are we would adjust oil grades because of temperatures.

 

To me, this is an interesting problem as it seems to apply directly to the vehicles initially built by GM as a new sheet of paper car, the Saturn S series. They in general seem to exhibit worn out engine symptoms at about the 100,000 mile mark as exhibited by the number of concerns raised by owners of them in the forums.
A little research indicates that they are not the only brand showing symptoms of excessive wear but they are the one covered by these forums.
As Derf has pointed out there has been major changes in improvements as applied to motor oils, and many in the last couple of decades in which oil weight as used to describe the oil in terms of the definition of viscosity may change as a function of time and use in an engine. But, oil is still specified to be used by the means of viscosity. Such as 20 Weight or 30 weight or a multi viscosity of 5w20 or even 20W50 which indicates the working viscosity equivalent at a cold and then a hot ambient temperature application.
A light weight oil as indicated by a viscosity reading for winter conditions and a heavier viscosity for summer.
It is the multi-viscosity oils which may seem a little confusing but simply stated the first number is a viscosity index identifier for winter use the 2nd number one as applied for summer.
It is todays version of oil viscosity recommendations that I can trace in my own library of data dating back to 1923 where in the PRACTICAL LUBRICATION for the Automobile, a lubrication manual on how to use the various lubrication oils manufactured by Standard Oil Company of New York, that is of the Socony motor oils of the time. The 63 page manual is full of practical information up to and including building a garage to park your car in and then outfitting it with all the proper goodies. Many of it's suggestions are dated and improved upon by technologies advancements in engine manufacturing and oils constant changes. A recommendation of changing oil every 500 miles has been superseded by many advances in both products. And the recommendation of the correct grade of oil to be used in the winter and the summer. In this 1923 document, the correct grade is not called out in viscosity numbers but in the words Light (L), Medium (M), Heavy (H) and Extra Heavy (EH) as the viscosity numbers had not be defined at that time.
But the concept of a lighter oil in the winter and a heavier oil in the summer was well established.
The manual covers a wide range of subjects and for a gear head is of interesting reading but it repeats a common thread using bold print for emphasis which says "Correct Lubrication is the cheapest form of insurance in which to invest."
As I was raised on the philosophy and learned the hard way how true it is I find it difficult to understand why a winter grade oil, that of a multi-viscosity of 5W20 has suddenly become a year around recommendation when manual after manual makes reference to this type as a winter grade oil to be used strictly at ambient temperatures of at or below freezing and if it is in use at higher temperatures vehicle speeds be limited at a maximum of 50 mph and only for short distances.
If those limitations are indeed valid than reports of high mileage vehicles similar to the reported track record of the Saturn S cars which have the OEM recommendation of 5W20 oils also have been reported of excessive oil consumption by 100,000 miles make perfectly good sense. The engines are worn out.
Yet for those few people who are able to report high mileage Saturn S (and other vehicles) that have had a steady diet of an oil of a viscosity more in line with the oil vs ambient temperature charts which show no excessive use of oil, thus no symptoms of worn engines.
There seems to be a message there some where. If one looks hard enough.
My two vehicles which I can indicate the use of ambient temperature compatible oils the Saturn and a 2007 Chrysler 3.3 V6 at 100,000 miles used no oil between oil changes.
And oil change being service at 4000 miles. If synthetic, a filter and a quart of oil, if dinosaur based a full oil change.
Now my 3.6L V6 Dodge with variable cam shaft technology is using 10W30 Mobil 1 and the engine is recommended to use 0W20 or 5w20. It seems to be using at least 1 quart of oil every 3000 miles. It is not showing any Cam Shaft positioning errors and while the vehicle, a Van is a very large box shape with zero aerodynamics visible at least the 6 speed transmission tends to keep the engine in the higher rpm ranges for things like passing and pulling hills still manages to get phenomenal fuel economy in both city and country driving while HP rating is close to that of pony cars with the huge engines of the 1970's.
It's interesting!
Technology has shown improvements some where.

 

Think ya have a typo in there, Unc.

S car recommended oil = 5W30, not 5W20. Even back when I had my 92 SL2 it was 5W30. To my knowledge it never changed throughout the life of the S series engines.
-------
"Engine Oil
SAE 5W-30 with the "Starburst" Symbol
GM Part Number 21007582, 32 oz."

--- source: 1997 Saturn Owner's Handbook (=Manual), pg 331.
Currently located on my desk for a completely different reason.

 

I was not aware of the recommended oil being a 5W30 and it might very well have been. But 5W20 or 5w30 there is a track record of the engines failing catastrophically at about 100,000 miles and assuming a regular maintenance of a 5Wsomething oil it is a fair assumption that the oil can be directly blamed for the failure rate of the engines if compared to those vehicles that were operated with something different in terms of viscosity. When this car was purchased the dealer recommended a 10W30 motor oil for this car and it was maintained as such until about the year 2000 when Valerie and I became a couple and I continued the maintenance of the car using a 20W40 oil I used in all my cars. As such the vehicle never developed a tendency to use oil.Directly or indirectly a 5w something motor oil has been causing motor failures and early oil consumption tendencies in what is growing to be a large number of vehicles.
There are a variety of web sites at the present listing vehicles with what is presumed to be a high rate of oil consumption. All of which are directed by OEM to use a zero or Five w something motor oil. There is a problem out there.