Ford Powerstroke Diesel Forum banner
Status
Not open for further replies.

Another take on the Oil debate

79K views 144 replies 63 participants last post by  Heavy_GD 
#1 · (Edited)
This is pretty solid information from my uncle. Hes an engineer and one of the smartest people i know. I boldfaced a section that seems rather important ot the PSD.

This is an Email conversation between dad and my uncle...

Uncle:
I thought I would send some information on motor oils. If you read any of the forum questions and answers you can get all kinds of misinformation.

I did a little bit of review and finally got my brain into gear concerning TBN. There are many different kinds of acids and bases. Examples of some common acids are sulfuric (battery) acid, acetic acid (vinegar), and lemon juice. Some common bases are some drain cleaners (lye, which may include potassium hydroxide (KOH) and sodium hydroxide (NaOH). Other bases include antacids (for stomach acid) and baking soda which contains sodium bicarbonate (NaHCO3).

After I have refined them a little bit, I will send some notes I got from the internet which may be worthwhile. In the mean time, TBN is Total Base Number and is expressed as the equivalent (in neutralizing power) milligrams of potassium hydroxide (KOH) per gram of oil. In practice the oil formulators use bases that may contain magnesium, calcium, etc.

The sulfur in diesel fuel tends to contaminate the crankcase oil from piston ring blow-by as sulfur dioxide. In the crankcase, moisture reacts with sulfur dioxide to create sulfuric acid. Oxidation of engine oil also contributes to formation of some weak acids. The acids that are formed then tend to corrode engine parts. The function of base additives (expressed as TBN) is to neutralize engine oil acids. As the base additives neutralize acids, they are used up (as is baking soda when it is used to clean corroded battery terminals). You can see that with low and ultra-low sulfur diesel fuels, the TBN for new oil can be lower than it was for the previous high sulfur diesel fuels because the potential for acid formation is reduced.

Of possible interest is a note I came across in a study of biodiesel fuel that indicated certain types produced much more acid during combustion, and that ended up causing faster depletion of the base additives. I don’t know that that has anything to do with the reprocessed greases/oils that you are using, but it might be good to have your oil tested at some point if you haven’t already done that. The following highlighted note was part of a discussion of TBN and TAN (Total Acid Number) that I came across.
In the past, standard practices for determining optimal drain intervals using fluid analysis have required testing the oil for TBN and TAN. The theory was that when new, an oil’s TBN is high and its TAN is low, and the longer the oil is used, TBN decreases while TAN increases. The point at which they meet is the optimal time to change the oil. It is important to note that ASTM D-4739 should be used when testing the TBN of used (in-service) oils as opposed to ASTM D-2896, which may be used when testing TBN in new oils. ASTM D-4739 uses a weaker acid for titration than does ASTM D-2896 and, therefore, produces slightly lower TBN results.
Historical test data shows the relationship between TBN and TAN to be quite consistent. TAN just begins to increase when TBN depletion reaches 50 percent. As the TBN drops below 50 percent, TAN begins increasing rapidly. So in reality, TBN depletion can reach about 65 percent before it becomes necessary to change the oil.
I am attaching an oil viscosity plot of several 5W-40 and 15W-40 oils on a partial ASTM grid. It looks somewhat like a log-log grid, but it was actually created by hand I believe in the mid-1940’s so that oil viscosity measurements would plot as straight lines. You will notice that on the 40 weight end of the plot they all cluster around 15 centistokes at 212F. However, at 0F the viscosity of 15W-40 is more than twice the viscosity of 5W-40 synthetic. The 5W-40 flows more easily on cold starts, and also reduces starter load. An additional benefit might accrue for use in the 6.0 liter Ford, which uses engine oil to operate the fuel injectors. Synthetic oils are tougher molecules and resist mechanical shearing which definitely can occur when oil is compressed and released as in this application. I mentioned to the service manager at Jim Townsend Ford in Shawnee that this arrangement sounded like an argument to use synthetic oil, and what did I find on line but a 5W-40 Motorcraft synthetic oil! It plots directly on top of the Shell Rotella T synthetic 5W-40. The Motul oil is what I use in my VW.

Dad:
Interesting. Looks like Rotella 5W-40 synthetic is much better than motorcraft synthetic of same viscosity. I may have to start using a synthetic. I periodically send a sample of my oil to Blackstone for testing. On my last report, SUS viscosity was just a tad low at 210 degrees F(67.2 versus 69-80)., cSt viscosity @ 100deg. C. slightly low at 12.20(12.7-15.8)). Flashpoint was 410 versue averages of greater than 410. Lead was high at 9, when it should have around 5, but everything else was within normal ranges. I'll probably have it tested again at next oil change. What do you yhink about amsoil? That seems to be highly touted.

Uncle:
Actually if you look at lines 2 & 4, the Motorcraft and Rotella just about overlay each other. It might be that the Motorcraft is Rotella. Saybolt Universal Seconds is rarely used for motor oils. Centistokes is more universal for several reasons, and it is easier and probably more accurate to measure centistokes (actually centipoise and convert to centistokes) with a rotating spindle viscometer. Yes, 12.2 cSt is a little bit low. What oil is that? I would like to use synthetic, and probably will next time, but boy it is sure hard to come to grips with cost. I have a gallon of Rotella 5W-40. I just need to buy 3 more gallons.

Somewhere I have a curve to convert SUS to cSt, and if I come across it I will send it along. It is very nonlinear on the low end, so it takes a curve to do it easily. If you cut through all of the sales promotion hyperbole about Amsoil, I imagine it is a good oil. I am attaching a plot of their 5W-40 diesel oil specs. They tout being a PAO (polyalphaolefin) basestock oil, and that is good. PAO basestocks are synthesized from smaller homogeneous molecules, and the larger the synthesized molecule the higher the viscosity of the basestock. (At Centrilift we used PAO oils from 6 cSt to 100 cSt at 100C for electric motor fills. I was instrumental in getting the conversion from white oils to PAO oils because they are tougher and stand the heat better.) I think some synthetic motor oils have some diesters in them, and that also is good, but that is just my speculation. Between the three oils, I would let price dictate, because I think they are pretty similar. I wouldn’t consider Castrol because from all I know it is made from a highly refined hydrogenated white oil, but it is still a mineral oil.
 

Attachments

See less See more
#3 ·
Interesting commentary. I know my truck runs better just after I change the oil, but it doesn't last long, synthetic or not.
 
#4 ·
Mine is due for a change real soon. Being that it is gonna be real cold soon should I go with a 5w-40 versus the regular 15w-40 or does it matter? Is it a thinner oil if the first number in oil viscosity numbers is lower?? Wouldn't that benefit me in cold temps??
 
#5 ·
I run rotella syn 5w-40 year round. 4-5k oil change intervals.
 
#6 ·
shops always say the ol' 3 months or 3000 miles which ever comes first.. if i went 5k on mine i would change it once a year, i only drive like 9k a year.. wouldnt it be bad to let the oil stay in the motor for that long???
 
#7 ·
Rob, according to all i read here and other sorces, a 5w40 is definately a thinner oil and will make those cold starts easier on your rig. And the synthetic molecular structure will resist shear better than standard oil. I have heard repeatedly that Rotella Syn is not a true Syn but a blend of the two but Motorcraft now carries a 5w40 syn in the 5 quart jugs (for out 15 quart diesels) and thats what I will use on the next oil change.
Funny thing is, last spring i accidentally bought this 5w40 Syn, got home and started pouring it in the truck (after i drained) and about the time i poured in the last gallon, i realized this was a Syn and it said nothing on it about diesel engines so i though i had screwed up...so not knowing this was actually a good oil for my diesel, i drained it out (60 bucks worth) and tossed it, went back to the store and bought the 15w50. Later realizing i should have used the oil i wasted. :doh:
 
#9 ·
I moved it again Clay...:poke :hehe:
 
#11 ·
How do you read the graph, are the higher number of centistrokes good. I use reg motorcraft 15-40 every 3000 miles, I used to use nothing but syn oil but now that i need 15 qts i cant afford it. I have spent a lot of time and a lot of frustration trying to figure out what to use with my budget, and all the daily miles I put on my truck. Im concerned with using the reg motorcraft 15-40, especially since it came with a semi-syn from the factory. I just cant figure out what to use
 
#13 ·
found this and did a cut and paste

This info was created by Jdub on Supramania. He is THE MAN when it comes to this stuff. I think it would do the world a great good to learn this :



Next is the regarded as "High and mighty" Mobil 1:

The only reason I'm doing this is 1) Mobil 1 is a very popular oil and 2) Mobil 1 is not entirely what it claims to be.

Mobil 1 HM 10W-30 is API Service Category SL,SJ,CF. It meets ACEA A3/B3 and A3/B4 requirements. Mobil 1 HM 10W-40 is API Service Category SL,SJ,CF....it does not meet/list ACEA specifications.

Here is the MSDS

Both oils are on par with what you would expect for their given grades. Both have excellent flash points and pour points...the 10W-30 is very good pour point wise, it's good down to -54 deg C. IMO, the 10W-30 would be a great all year oil...there really is no point changing to the 10W-40 for the summer. the 10W-30 will perform very well even during the summer heat. Both oils have a robust additive pack.

Mobil 1 uses Group III + alphaolefins (AN) base oils including polyalphaolefins (PAO)...however, the primary base stock is Group III.


Quote:
In 2006, the results of a gas chromatography test on Mobil 1 5w-30 EP were posted by an industry expert on the popular motor oil discussion website BITOG. It showed the oil to be primarily composed of a less expensive, Group III processed mineral oil. Until this time, Mobil 1 was believed to be a true synthetic, utilizing a Group IV (PAO) base stock. The release of this information has led to a backlash against Exxon Mobil's lubricant products in many automotive communities. Ironically, in 1999, Mobil fought Castrol's change in formulation to a Group III base stock in motor oils being marketed as fully synthetic. Mobil claimed that Castrol was deceiving their customer base, while degrading their products. The National Advertising Division of the Council of Better Business Bureaus eventually ruled that Castrol could continue to market their SynTec line as a fully synthetic motor oil. Exxon Mobil currently refuses to comment on the primary base stock of their Mobil 1 series of oils. This has only added further confusion over the exact definition of the term "synthetic oil."

So far, I have not seen any further info on Mobil 1 oils that contradicts the above quote. I have seen this US Patent application by Exxon Mobil:

http://appft1.uspto.gov/netacgi/nph-...DN/20060211581

The cliff notes on this is Exxon wants to patent the process to utilize Group III base stock with AN and PAO modifiers for use as "synthetic" base stock...one would assume this means their Mobil 1 line of oils. Since PAO and AN are rather expensive, the majority of the base stock is very likely to be Group III...by definition not a true synthetic oil. Appears to me they want to sell us oil marketed as a synthetic, at synthetic prices and increase their profit margin....I guess last year's record profit for any US company wasn't good enough

Keep in mind, Group III base stock does not make Mobil 1 a bad oil...it's actually very good. Take a look at the above pics...very clean...no deposits at all. It justs chaffs my tail pipe to pay synthetic prices and get a Group III oil...especially when Exxon will not come clean about it. Pennzoil Platinum is also using a Group III...the company makes no secret about it. In fact, their Platinum line is among the best there is due to the technology behind refining it.
 
#15 ·
well i was hoping someone would maybe explain it a bit, could it true that mobil 1 might not be all it says it is, and that it overpriced for what it is. I dont quite understand the different grades of the ingredients, like mineral oil oils. And shouldnt mobil 1 have a POA basestock oil and not mineral oil.
 
#18 ·
Interesting. I am somewhat partial to my Rotella T dino oil, but have been considering getting a bypass filtration setup and switching to synthetic. Next comes the debate with myself as to which synthetic to use. If nothing else, this thread got me to do a bit of research and Rotella T 5w-40 Synthetic appears to be mostly mineral oil. In fact, I see no mention of PAO or AO oils mentioned in the MSDS. The MSDS from a Shell site
Shell Lubricants MSDS
on this MSDS
http://www.equivashellmsds.com/Display_MSDS.asp?ID=196553
says the "COMPOSITION/INFORMATION ON INGREDIENTS" is "Highly refined mineral oils and additives".

I never really thought about it, but it is interesting that they can list their ingredients as "Highly refined mineral oils" (and additives, presumably synthetic) and still call it a synthetic oil. Does anyone know what the requirements are for a company to claim an oil is synthetic?
-Aaron
 
#19 ·
I just tested my links and read the top of the MSDS. I think their link is broken. I just realized that the MSDS that it pulled up appears to be wrong. I clicked on their link for 5w-40 Rotella T Synthetic and found that takes me to a MSDS for Omala® Oil 3200 that says its use is a Gear Lubricant. Maybe it isn't the correct MSDS? I may do some more research into this and see what I can come up with. Take my above post with a grain of salt for now.
-Aaron
 
#20 ·
Ok, I found the correct MSDS and since my earlier post was pretty misleading I figured I better set the record straight. The Rotella T Synthetic 5w-40 lists the following for "COMPOSITION/INFORMATION ON INGREDIENTS": Blend of synthetic hydrocarbon, polyalphaolefins and additives.

Sorry for any confusion. I guess I should have paid a bit more attention to what I was reading.

-Aaron
 
#22 ·
I've been useing Shell Rotella T synthetic for several (6) years now in all my vehicles,6. I change oil and filter on the 10,000 mile mark and change the filter and top off the oil at the 5,000 mile mark. No problems with any of the vehicles. I'm considreing pushing the oil change to 15,000 miles.
 
#23 ·
You and me both. My old 7.3 has 160K and running 5-40 syn rotella.
oil filter on the 5000's
oil filter, fuel filter and motor oil on the 10,000's
I'm running wix filters right now but thinking of switching to the amsoil single spin on bypass.
A friend with a duramax has had good luck with the filter
 
#24 ·
Very interesting read. I my self use AMSOIL. Amsoil uses basestock IV additives and is what I believe to be a true synthetic. Interesting part is that they actually by there basestock from Mobile. I noticed that when I switched all my fluids out in my truck with Amsoil it seemed to run a lot smoother and quiter and has been ever since. I am anxious to do a UOA to see what the results are. I currently have 15w-40 in but getting ready to switch to the 5w-40.
 
#27 ·
oil debate

I think this is one of the most important posts available.
Cost is irrelevant.I use syn.,but how about the filter.Wix or not?????????
I believe the post in here are well though out concerning the oil viscosity.
Everyone here should read it.
The second most in need has to be filters. Oil & fuel
I hear many different choices.From the easyest available to the most expensive and hard to keep up with.

How important do you think it is?
thank you

ps im only familure with wix. its avalible,cheep,& good .
i always use syn
 
#29 ·
I've always heard that Fram oil filters are crap. I have no basis for this, just what i've heard. I use motorcraft for now till i find something definitively better. I am curious about which fuel filter though since I'm due for a full fluid/filter change and going to synthetics throughout.
 
#30 ·
oil debate

Interesting: today while ordering grafite poly bushing.I asked why I couldn't get wix oil filters at this auto store.My friend,who I have known for at least 5 yrs,told me he had a new bulleltin on filters.
The big surprise was that they all about the same.
He told me if you want a better filter you need to buy a better filtering system.Other wise mobile 1,K&N,motorcraft were better than most ,but the others were about the same.He laught and said if I'd like to pay more.He take my money.:hehe:I used the internet today to verify it ,but I can't seem to get the micro #'s for most of the filters.Now we are talking about auto parts stores not proffesional oil or fuel filtering systems............
Im going with motorcraft,but Im looking into a new system.
Good luck...
 
#31 ·
I don't think the micron filtration rating on the filters is the problem with the filters, it's the filter construction and the size. From what I understand only the motorcraft and one other brand fit in the filter housing on the 6.0 properly because Ford owns the product patents on these filters. Be careful when trying to save a few pennies on your aftermarket filters, saving a few pennies could cost you BIG dollars. I even quit buying my motorcraft filters from walmart because when I changed my oil and filter once the filter media had pulled away from the frame that holds it together. That meant that my oil was not getting filtered!
 
#33 ·
The motorcraft 15W40 oil says it's only good down to freezing. If you drive in temperatures below freezing it calls for a 5W40 oil. I use full synthetic 5W40 Rotella in the winter and 15W40 Motorcraft in summer. I change my oil 4 times a year (7,500 miles with 2 changes on Rotella and 5,000 miles with 2 changes of the Motorcraft.)
 
Status
Not open for further replies.
You have insufficient privileges to reply here.
Top