Another Oil Question

[csimo]

I agree that we shouldn't waste lubricants! My statement was pointed against the use of 30 weight oils in the Duramax. It is just plain irresponsible to tell someone that "it's OK" to run the wrong oil, and that person is not the one on the hook if GM denies your warranty. The manufacturer of the oil does not stand behind a product not used as intended, and using a 30 weight oil in a application that requires a 40 weight oil is an example of a product not being used as intended.

I don't care what brand of oil a person uses as long as it meets the manufacturers requirements. The truth is that any major brand of oil will give you the protection you need. I personally use synthetic oils in all my vehicles, but I also know that I'm really wasting money. The best and only completely independent test of motor oils I know of was done by Consumers Union. They ran many vehicles a total of over 4 million miles under controlled conditions. There was no measurable difference in engine wear between drain intervals of 3000 and 7500 miles, and no measurable difference in engine wear between conventional and synthetic oils. Even knowing that I still prefer synthetic oils and will continue to do so as a personal preference. I drain at the maximum interval allowed by the manufacturer (usually 7500 miles). As many have discovered here through oil analysis the real reason we change our oil is NOT because the oil is "worn out", but because it has become contaminated with dirt and other contaminants. We change the oil to flush out those contaminants and replace the old dirty oil with new oil that is capable of maintaining the additional contaminants in suspension. No motor oil in the world can stop from becoming contaminated and extending the drain intervals too long just keeps those contaminants in your engine. Motor oils, at least the good ones, are designed to keep contaminants that are too small to filter out in suspension. These oils usually look "dirty" due to this desirable factor. Some cheap oils that look "clean" after a few thousand miles are not doing their job properly. An oil that fails to maintain the contaminants in suspension allows them to precipitate out and become what we call sludge.

GM is working in the right direction by getting away from absolute milage ratings for oil changes. The oil life monitoring systems are still in their infancy, but it is a step in the right direction and someday they will be extremely accurate in their determination of the need for an oil change.

[mdrag]

Here is a link to Mobil's website and the Delvac 1 FAQ, plenty of great info here:

http://www.mobil.com/USA-English/Lub...ne_Oil_FAQ.asp

Below is a copy and paste of a few pertinent FAQ:

11. Why doesn't Delvac 1 come in a 15w-40 viscosity grade?
The synthetic base stock used in Delvac 1 naturally has better low-temperature flow characteristics than a conventional engine oil. This results in the SAE 5W grade, which provides easier starting and faster oil flow characteristics than an SAE 15W grade. With the excellent film strength of the synthetic-based stock, and the tuned additive package, we can offer the advantages of better low-temperature performance and improved fuel economy -- while also providing better lubrication protection at hot engine operating conditions than a conventional SAE 15W-40.

12. When can Delvac 1 first be used?
You can start using Delvac 1 in new vehicles at any time. Or, you can start using Delvac 1 in an engine with a number of miles already on it. As long as the engine is in good mechanical condition, you can start to get the advantages of Delvac 1 today. Refer to Mobil's Extended Drain Policy Guide for exceptions (available by calling 1-800-662-4525). You can also use Delvac 1 in an overhauled or rebuilt engine. However, a rebuilt engine may contain swarf or abrasive material inside the engine. In this situation, you would be best served by using a short drain interval on your initial oil fill. Delvac 1 will still work in this situation, but it would be less expensive to use a conventional oil for this first, short-duration change.


19. Since Delvac 1 is a 5w-40, will it void warranties if I use it?
No. Delvac 1, because of its high Viscosity Index (VI), provides a better protective film at higher temperatures than conventional SAE 40 weight oils, while remaining fluid at lower temperatures than a conventional SAE 15W weight oil. Mobil Delvac 1 meets all engine manufacturers' requirements where an API CI-4, CH-4, CG-4 or CF-4 oil is recommended.

30. How does Mobil Delvac 1 compare to competitive products?
There are many new entries in the synthetic and partial-synthetic commercial engine oil market. But they have a tough time matching the 20 years of experience we have with field performance of synthetics in diesel engines. You can be assured that Mobil Delvac 1 not only works with the latest engines, but also performs in all of the four-stroke diesel engines that have been manufactured over the past 20 years.

And, all of the evaluations we have performed on competitive products over the years have not yet identified an oil that can match the performance of Mobil Delvac 1.

Hard to argue with #19 when prominently displayed on Mobil's website specifically addressing warranty questions.

Tastes Great!!! Less filling!!!

[LanduytG]

I am not going to get into the oil war thing here. people have to make up their own mind on what is best fr them to use. I am only going to say one thing and then I am done.

What makes you think that a 30 weight can't be formulated to be better than a 40 weight oil. After all technology is growing by leaps and bounds, thechnology is changing daily.

Amsoil has done extensive testing with the Series 3000 5W-30. If Amsoil is snakeoil then why hasn't the FTC done something about it. Times have changed and I think we need to look at things from a different angle.

The manual recommends 15W-40 but just how much test do you think they have really done? The Europeans have been using weight oils in diesels for some time now. It WILL be in the US by storm in a couple of years.

Another thing to concider is we went to the moon and most said it couldn't be done. We now have computers that fit into our shirt pocket that have way more power than the computer used to take the rocket to the moon. Technology is CHANGING, so don't be so quick to think a 30 weight is bad news.

Greg

Unsurpassed Engine Protection
AMSOIL Series 3000 Synthetic 5W-30 Heavy-Duty Diesel Oil's higher VI provides a better protective film at higher temperatures than conventional SAE 40 oils, while remaining fluid at subzero temperatures. In every engine tested, AMSOIL Series 3000 Synthetic 5W-30 Heavy-Duty Diesel Oil's unique technology significantly reduced ring wear, cylinder bore polishing, cylinder lining wear, oil consumption, piston deposits and ring breakage.

[chuntag95]

Trust the manual if you want, but when I went to buy the recommended lubricants for something other than engine or transmission oil, 3 of the 5 were no longer being used or available from GM. That was in 2002 on a 2002 vehicle. Hmmmmm. I think I have to let my experiences and some common sense take over.

[csimo]

LanduytG, you asked: "What makes you think that a 30 weight can't be formulated to be better than a 40 weight oil." Neither is better! They are different products designed for different purposes. It's like asking "which is better a Red Delicious apple or a Granny Smith". Better for what? Taste? Cooking? Peeling? Canning?

A 30 weight oil has the properties of a 30 weight oil. Those properties are not the same as a 40 weight oil and will never be. A 30 weight oil does not meet the specifications of a 40 weight oil. That doesn't mean it's not as good... just a different product designed for a different purpose.

Our engines were designed and tested to run on a 40 weight oil. 15w-40 is mentioned in the manual, and 5w-40 synthetic is approved in a TSB. How much testing did they do? I don't know, but I do know they didn't pick that number out of the sky because it sounded good. I'm sure they would have liked to approve a 30 weight oil since it would have provided slightly better fuel mileage, but they apparently didn't feel that it was the proper lubrication for the engine. I believe them.

Someone mentioned film strength. That is but one property of oil. You could make a lubricant with excellent film strength that is a poor motor oil. You could make a lubricant that performs well under extreme pressure and it not be a good motor oil. It's the entire package of properties that you need. Are there "bad" motor oils on the market? Probably not since they all need to meet the minimum API published specifications. Some are better than others, but as long as you stay with a major brand motor oil you will be in good shape. Even the best motor oil in the world won't keep your engine from wearing out.

[bryantch]

this is a link to "Everything you ever wanted to know about oil v1.2". cant say i understand all of it (or care to) but some of you guys may find it interesting and informative.

" Multi viscosity oils are one of the great improvements in oils, but they should be chosen wisely. Always use a multi grade with the narrowest span of viscosity that is appropriate for the temperatures you are going to encounter. In the winter base your decision on the lowest temperature you will encounter, in the summer, the highest temperature you expect. The polymers can shear and burn forming deposits that can cause ring sticking and other problems. 10W-40 and 5W-30 require a lot of polymers (synthetics excluded) to achieve that range. This has caused problems in diesel engines, but fewer polymers are better for all engines. The wide viscosity range oils, in general, are more prone to viscosity and thermal breakdown due to the high polymer content. It is the oil that lubricates, not the additives. Oils that can do their job with the fewest additives are the best."

http://www.repairfaq.org/filipg/AUTO...l#OILFACTS_004

this forum sure has lively debates to keep things interesting...keep it up.

[LanduytG]

Yes 30 weights are different than 40 weights, but what about the additve package used? Could be that this is what makes the 30 weight perform like a 40 weight? May be they have a base stock that is a 30 weight but can perform like a 40 weight. But then you have those that will screw it all around to make it sound like its impossible.
Greg

[ 01-08-2003: Message edited by: LanduytG ]</p>

[TraceF]

Again agreeing with csimo. You are right on track.

It is critically important to use the correct specification oil (or better- CI for example vs. CH) and secondarily important to use the correct grade (w40 for example).

Anything #w## (5w40, 15w40, etc) means "winter". Explained well above. AnythingW (30W, 40W, 50W, etc) means "weight" and applies only to straight grade lube.

Greg- Following your logic, would you also advocate using Mobil Synthetic 0w30? It doesn't claim to meet the C spec but it is a G4 stock and probably meets or exceeds the CH spec. Mobil doesn't try to apply it because the lube is inappropriate for any current diesel application, in other words it doesn't meet any manufacturers recommendation. Why go for a C spec? The spec comes from the manufacturer, not the lube blender as explained above.

Incidentally, Mobil Delvac was available in a diesel 10w30 blend well over a decade ago. It had an extremely high VI, around 170 if memory serves me.

I would presume that you would get a good result from the 5w30 in the short term but as JK said earlier the w30 won't give the shock load protection of w40 and 250k to 500k miles is where you will see the real result of your choice.

For the most part, not always, but for the most part, the same additives are used in mineral base lubes that are used in syn base.

Syn based lubes handle extreme heat and extreme cold better primarily because of their molecular structure and how it interacts with additives, not just the additives alone. Again I say- if all of the engine systems are working properly, the internal engine temperature is reasonably well regulated.

Syn lube can however make a big difference in the rear axle for example where temperatures are not well regulated and increase dramatically when towing heavy loads.

The CU oil test was widely publicized but was actually a very similar test to one done earlier by QS in Atlanta with the Atlanta City fleet. The findings were similar. The automotive applications were going 3k and 6k with oil analysis with very little difference in wear metal concentrations from one interval to the next.

I'm done.

[Tsckey]

A plausible argument can be made for using 5w-30 synthetic oil in our trucks--many people have made compelling arguments for the existence of extraterrestrials, too. The question in my mind is why would you want to? What are the benefits of straining to make a 30w oil do the work of a 40w when high quality variants of the latter are readily available? Presumably, there may be some theoretical gains to be had in fuel mileage from the minute reduction in internal friction, but as JK points out, these come at the risk of greater exposure to shock loads on the hard working parts.

I'm guessing the GM and Isuzu engineers didn't just pull the 15w-40 specification out of the air because big diesels use it. I'm figuring they had something in mind associated with durability over the long haul. I have frequently read comments like "I've been using 'X' for 10,000 miles with good results." Well, diesel engines age the way mountains erode, over the long haul. I would not expect problems to arise quickly from marginal lubrication, but over a period of many thousands of miles and especially under heavy loads. I may be overly conservative or cautious, but that's why I'm siding with the 40w crowd.

TC

[CleviteKid]

"30 weight or 40 weight, that is the question."

Viscosity is easy to understand, it is the resistance to flow. Yes, DuraMax did lots of testing, but they also designed the engine to use the most common and best diesel oil, 15w40.

The engineering methodology for designing engine bearings is Journal Orbit Analysis, the solution of the coupled partial differential equations for hydrodyanmic lubrication in short bearings. This was first explained in SAE Paper 690114 (1969) by my collegues from Clevite. This analysis is done every degree of crankshaft rotation for 720 degrees of the complete four-stroke cycle. It takes into account the inertia of all the parts, the friction of the piston rings, the firing pressure and the intake and exhaust pressures. It also figures in the increase in temperature and resulting decrease in viscosity of the lubricant while being sheared by the relative rotation of the crankshaft journals and the bearings.

Computed values, verified by years of comparison to engine dynamometer and field experience, include oil film thickness as a function of time, oil film pressure as a function of time, integrated dwell of the journal at specific locations on the bearings, and the optimal placement of oil feed holes in bearings and crankshafts. The minimum oil film thickness should exceed 200 millionths of an inch for long durabilty, and the peak oil film pressure from combined hydrodynamic wedge and squeeze film effects should be less than 20,000 psi to avoid premature fatigue cracking failure of the bearing liner metals, either bronze alloy or aluminum alloy.

I have used Journal Orbit Analysis on everything from 14,000 rpm CART racing motors to bearings 36" in diameter in engines with a top speed of 90 rpm, and it is well validated. Clevite and its competitors do dozens of Journal Orbit Analysis calculations for the engine builders every year. It is THE ACCEPTED TOOL for bearing design and analysis.

In our diesel engines, all the parameters are optimized for the best oil film thicknesses and bearing pressures with 40 weight oil. Substituting 30 weight will mean thinner films, higher pressures, eating into the factor of safety designed in by the engineers. Only that generous factor of safety allows 30 weight to appear to work for a reasonable length of time. 40 weight is better. And yes, I am referring to the high temperature end of multi-weight oils, such as 15w40 and 5w40.

The additives in the oil are first for suspension and dispersion of dirt, such as combustion soot, and then for oxidation resistance of the oil, and lastly for boundary layer lubrication of piston rings and gears. The additives have nothing to do with the oil film properties in bearings, that is controlled by the viscosity as measured in viscometers.

As an aside, much of the information on engine oil floating around on the Internet is 5 to 10 years old, and some of it was actually accurate when first written. As stated by other posters, synthetic base stocks tend to have naturally high viscosity indices (or indexes to some of us), so they meet multi-grade requirements without any viscosity index improvers, like STP. Most major brands of synthetics have no VI improver in some grades, and just a little in other long-spread grades, like 5w50.

I hear the bell ringing, so class is dismissed for today. There will be a quiz tomorrow.

Dr. Lee

[woundedbear]

johns,
Although not the intent of your original post, you most definitely have reopened a debate on oil. For that I am thankful. This is the first time, to my knowledge, since the Duramax has been launched 2+ years ago that Amsoil 5W-30 diesel oil usage has been discussed to this detail. What took so long?

I am hoping for the input of one more person, that being George Morrison. I realize that there might be an obvious conflict of interest here that might prevent him from saying anything, but I thought I would put the request out there seeing that he seems to be TDP's resident expert on engine lubrication.

csimo,
You seem like an intelligent and logical person, but you also seem, from your posts here and in previous topics, that you have a chip on your shoulder against Amsoil. I respect that, everyone is entitled to their opinion. I am the first one to roll my eyes at Amsoil publications I receive in the mail that say a lot without saying anything...I think you know what I mean. I am also not keen to their multi-level marketing technique. But, behind all of this, I believe there lies a good product. I believe that many here would agree.

You asked "why in the world would you choose to disregard (GM's) recommendations and go with a product that does not meet their specifications?"
How have I done that?

From the "2002 Duramax Diesel Supplement":
"...you can use SAE 10w-30 at temperatures above 0 degrees F..." And on their "Recommended SAE Viscosity Grade Engine Oils" chart, they recommend a SAE 10w-30 between the temperatures of 0 and 100 degrees F.

Amsoil Series 3000 5W-30 is also designated as a CH-4 oil.

When I referred to factual evidence in my previous post, I was referring to the two personal oil analysis results which did not reveal any problems. If 5w-30 was not suited for "severe shock loads" present in the Duramax, would I not have seen a problem here? I do not want to sound argumentative here, only looking for an answer. Am I wasting my money on oil analysis if I can get good results back while using unsuitable "snake oil?"

All that said...if many members here, that are much more experienced than me in the field of diesel engines, feel that a multi-viscosity 40w oil offers better protection and GM "prefers" it in their recommended oils, I am leaning towards a 5w-40 or 15w-40 synthetic at next change. I don't believe using 5w-30 will void any Duramax warranty, because the Diesel Supplement specifically "recommends" three oil viscosities, one being a multi-viscosity 30w oil. Nevertheless, I am looking to own this truck far longer than my warranty will be in effect.

[Kennedy]

Whenever a complicated lubrication related question pops up, ASK Dr. LEE !!!

Of course, his time will not always allow such a detailed response...

[csimo]

woundedbear, that's why I suggested you carefully check the latest TSB for proper oil requirements. GM has indicated on at least two TSB's that the Diesel Supplement for 2001 and most of 2002 was wrong. I believe all mention of any 30 weight oils has been removed.

The latest one says:

"Oil Viscosity for Cold Weather Operation

SAE 5W-40 viscosity oil designated as API CH-4 or CG-4 should be used if the ambient temperature falls below -18

[CleviteKid]

I failed to mention another important function of engine oil additives, neutralizing acidic products of combustion that find their way into the oil. One benefit of the coming lower sulfur fuels will be less acid in the crankcase.

Dr. Lee

PS I would amend Kennedy's advice to include asking George Morrison as well. If he and I agree, then you are pretty sure we have the correct answer.

[arveetek]

I'm by no means an oil expert, but 30W and 40W have different properties, thereby giving them either a 30W or 40W rating. Now, if a 30W is supposed to work just as well as a 40W, and have the same properties as a 40W, why is it then still classified as a 30W? That means that there are differences in the viscosity that separate the 30W from the 40W, right? So that means a 30W oil is still not going to have the same properties as a 40W, or work just the same, or else it too would be classified as a 40W.

Casey

[CleviteKid]

Right you are, Casey.

Dr. Lee

[HESS101]

I am brand new and making my first post. Not had an oil change yet but reading you guys intently. My 2003 supplement states the following:SAE 15W40 is best for your vehicle However, you can use 10W30 @ temps above 0*F.When its very cold below 0*F you should use 5W40 to inprove cold starting. I was ok until the last paragraph which stated:
"these numbers on the oil container show its viscosity, or thickness. DO NOT use SAE 10W40 or SAE 20W50". What happened here to the 40W theory.
Why in the world is 10W40 not recommended.Also is GM even considering Synthetics in their oil recommendations and has anyone talked to Isuzu since this is a relativly new partnership.
Thanks to all of you on your input. I have already gotten my moneys worth on just this one subject.
Thanks again
Steve

[csimo]

Hess101,

I think the reason that a 10w40 is not recommended is because there aren't any 10w40 oils that are CH-4 rated on the market. Could be wrong, but all I have seen are 15w-40 and 5w-40.

Isuzu is pretty much out of the DMAX, LTD picture now.

[4x4man]

I would be interested in hearing from Broker on which oil he runs in his trucks. He is the only one I know of that has run a DMAX over 400,000 miles. Anyway, just my thoughts.....

Bob

[LanduytG]

This 10W-40 has been available for years and I know several people using it. It is also CI-4 rated.

AMSOIL High Performance Synthetic 10W-40 Motor Oil is designed to provide maximum benefits in gasoline and diesel engines.

Product Code: AMO

AMSOIL High Performance Synthetic 10W-40 Motor Oil is Recommended for Applications Requiring the Following Specifications:

API SG, SH, SJ, CF, CF-2, CG-4, CH-4, CI-4
ACEA A2, A3, B2, B3, E2, E3
CHRYSLER MS 6395-H
CUMMINS CES 20071, 20072, 20076
FORD WSS-M2C 153G
MERCEDES-BENZ 226.1, 227.1, 228.3
MACK EO-L, EO-M, EO-M+
VOLVO VDS, VDS-2
VOLKSWAGEN 501.01, 505
ALLISON C-3, C-4
CATERPILLAR TO-2, TO-3
JASO MA (Motorcycle)


PRODUCT DESCRIPTION
AMSOIL High Performance Synthetic 10W-40 Motor Oil provides superior protection and performance in the most severe automotive driving conditions. AMSOIL High Performance Synthetic 10W-40 Motor Oil provides a wide range of protection in all four-cycle gasoline and diesel engines, including pickups, RVs, cars and off-highway vehicles. It is recommended for use in vehicles subject to stop-and-go driving, short trips, high temperatures, frequent trailer pulling and off-road use.

RESISTS HIGH TEMPERATURE VAPORIZATION
Conventional motor oils tend to "boil off" in high temperatures, losing up to 25 percent of their original weight. These vaporized oils circulate poorly, reduce fuel efficiency and contribute to excessive emissions and engine wear. AMSOIL High Performance Synthetic 10W-40 Motor Oil resists vaporization. In fact, according to the NOACK Volatility Test, which measures the weight loss of an oil due to evaporation, AMSOIL High Performance 10W-40 only loses 7.0 percent of its weight in high temperature service, surpassing rigorous European standards set at 13 percent weight loss in high temperature testing. The superior vaporization resistance of AMSOIL High Performance 10W-40 keeps engine wear, oil consumption and emissions to a minimum, while keeping oil circulation efficient and fuel economy high.

Greg