The VQ Oil Analysis & Oil Information Thread

[Ghost]

This is a thread for discussing oil attributes and collecting Used Oil Analysis (UOA) reports in order to determine which oil brands and weights are the best for the VQ engines. A UOA is a test done on an oil to measure engine wear and oil viscosity. The results allow us to see how well it has performed in an engine.

So far, the best performing oils are:
Amsoil 0W-30- It has very good to better than average wear results and good viscosity, especially for oil change intervals over 6k miles. A new formulation has come out, this is the old formulation.
Pennzoil Platinum 10W-30- This oil has the second best wear numbers of any oil tested so far, with three different engine test results all reporting the same findings. It's viscosity and TBN numbers mean it's not the best choice for oil change intervals over 3k miles or track days, though.
Schaeffer's 7000 5W-30- The best overall wear results, with low shearing and good for longer than average oil change intervals. A great choice for a 5W-30.
Mobil1 0W-40- This is a very robust "off-the-shelf" oil that's easy to find for the daily driver who does track days as well. Low shear and really good to average wear results combine to make it a versatile oil for regular or extended oil change intervals in any climate.

Oils I don't recommend based on the UOA's done so far:
Mobil 1 5W-30 and 10W-30- If you like Mobil1, then get the 0W-40. Otherwise don't waste your money on a premium oil with average to less than average results.
Amsoil ASL 5W-30- It's a decent oil, but it has consistantly shown high lead wear and the TSO 0W-30 has performed better with more mileage on it between oil changes. If you like Amsoil, then get the better performing TSO for the same money.
Royal Purple 5W-30- This is the worst performing oil to date, with high wear numbers and high shear. However, I only have been sent one UOA on this oil so it is not an average result.

How did I come to my conclusions? Read on, and find out how to contribute to your own engine's performance as well as the benefit of the Z community.

Each UOA is performed at a lab using oil samples that have been sent to them by the customer. Two of the most popular testing labs are:

http://www.blackstone-labs.com/
http://www.dysonanalysis.com/index.html

After running several tests on the oil sample sent to them, the lab sends a data sheet back to the customer that shows the general condition of the oil. The oil condition highlights issues such as engine wear by showing how much of certain trace elements were in the oil that came from the engine. An oil that protects well will have low traces of Lead and Chromium, for example. A UOA will also show how much the oil has broken down with use, and highlight the presence of any dirt, anti-freeze, sludge or fuel in the oil. The purpose of having a UOA performed is to examine the properties and effectiveness of a particular oil, as well as to see any problems within the engine that may be developing.

Oil Comparison Charts
I have compiled some charts with the UOA results from several oils in an effort to compare the pros and cons of each oil against each other. I include as much of the following as possible from each oil's UOA in my comparison charts:
Brand and Weight
Mileage put on the sample in between oil changes
Any oil added during the interval
Trace elements
Sustained or Kinematic Viscosity
Total Base Number

The top part of the comparison charts (The Blue Section) contains each oil brand and weight, the mileage on the oil, and any fresh oil added during the drain interval. This is important to look at when comparing oils, as an oil that had just 1,000 miles on it when tested will obviously fare better than an oil that had 9,000 miles on it when tested, even if it is not really a better oil.

The next part (The Grey Section) of the charts contain the following trace elements in parts per million, and reflect the amount of wear or additives in the oil. It is important to have lower numbers of iron, lead, chromium, aluminum, and copper. Lower numbers of these elements mean less wear on the engine's internals with that oil. Lower numbers mean the oil did a better job protecting the engine's metals. Listed below are possible sources of wear for each:

Silicon (Si): Dirt ingestion

Iron (Fe): Wear of cylinder liner, valve and gear train, oil pump, rust in system

Chromium (CR): Piston ring wear

Copper (CU): Bearings and bushings wear

Lead (Pb): Bearing corrosion or Extended oil change intervals

Lead (Pb): Bearing lining wear

Aluminum (Al): Piston and piston thrust bearing wear

Silver & Tin: Wear of bearings

The other trace elements are usually part of an additive package that oils use. An example is Molybdenum & Boron: These are normal oil additives to reduce friction. Some oils like M1 and Redline are very robust with Molybdenum, others use less of it. Zinc and Phosphorous are key elements in an additive known as ZDDP, a friction reducing agent that also aids in an oil's ability to withstand shearing forces. For more information on the different additives used in engine oils, see post #4 in this thread.

The last part ( The Red Section) of the charts has the Viscosity numbers and the Total Base Number (TBN).
The viscosity numbers are from a specific test to determine the viscosity of an oil at a given temperature, as measured in cSt (centistrokes). The reason some numbers are in deg F and others are in deg C is because different labs do different tests. The tests results that have deg F are what is called the Sustained Viscosity. The test results that have deg C are what is called Kinematic Viscosity. The details aren't really important. What is important is to look at the numbers and realize a higher number means a thicker oil at operating temperature, and a lower number meaqns a thinner oil at operating temperature. A higher or lower number is neither good or bad in and of itself, it is merely a measure of the oil's viscosity. If you had an oil with the viscosity of a 30 weight when new, and now has the viscosity of a 20 weight when used, that's bad. An oil that has thinned out with use has secumbed to shearing. How do you know what viscosity an oil had when new? There is a list compiled in a following post that lists the manufacturer data for viscosity at certain temperatures. We can compare the UOA result to the oil viscocity when it was new and see if it has thinned out at all from shearing. The more robust an oil is, the less it should shear, and the better it would be for a hard track day use or FI application. For more information on understanding oil viscosity, see post #2 in this thread.
The TBN (Total Base Number) is an indication of how much of the base stock was left in the oil to fight acids that build up as a result of oil oxidation. All engine oils break down over time and with wear. The result is an accumulation of acids in the oil. These acids are what forms sludge. The formulation of an oil's base stock and the additives in the oil work together to help prevent sludge from forming. The TBN is a measure of how well the formualtion is working to fight sludge and acid build-up. A high TBN means there is more base than acid in the oil. A lower TBN number means more acids formed over time than an oil with a higher TBN and the same mileage. It is a good indication, along with the viscosity numbers, of how robust the oil is over time. Therefore, a high TBN is the best indication of whether or not an oil is good for extended oil change intervals. Oils with synthetic base stocks and good additive packages tend to have higher TBN numbers over long oil change intervals. If you wish to know more about oil base stocks and how they influence an oil's performance, see post #6 in this thread.

The charts are attached below, and offer a comparison of different brands and weights. The oil brands and weights in red are average results from several tests. The ones in black, are single tests. The combined average brands and weight are more accurate in the results than the single tests, especially compared to those that did not report the mileage on the oil. There is also a comparison chart for oils that have been used in FI engines.

Finally, I am not a chemical engineer, petroleum engineer, or tribologist. I don't pretend to be the authority on engine oils. If I have made, and probably have made, any errors, please let me know and I will edit this as neccessary. I have tried to make things very simple to understand and read. If anyone wants to get more technical and in-depth then there is another site dedicated to that end, and I would like to give that credit where it is do. The explanations I have posted here are from that site; www.bobistheoilguy.com (http://www.bobistheoilguy.com/) and I encourage everyone to visit it.

A big thanks goes out to MardiGrasMax for sending me the first round of UOA data. Thanks also to everyone else who has sent me their UOA or posted it here so we can all benefit. The individual UOA's that people have sent are posted later in this thread. Feel free to post new ones if you have some UOA's done on your engine oil, and I will add them to the chart I made in this post for easy comparison. If it is an oil that is already in the chart, I will add your results to make a new mean average for that particular oil.

[Ghost]

Understanding an Oil's Weight
(or, what does a 5W-30 mean anyways?)

Nissan recommends several grades of oil in the VQ, depending on where you live and how you drive. The broad oil recommendation is a 5W-30 weight oil. An oil's weight, when a multi-grade oil like 5W-30, is a range of the oil's thickness when cold and when hot. The "W" number (such as the 5 of a 5W-xx oil) is the "winter weight" of an oil and is the measured viscosity of the oil when cold. The second number (such as the 30 of a xxW-30 oil) is the measure of the oil's viscosity at normal operating temperature. The normal operating temperature of an oil is 100 deg C, and the unit of measure is called a centistroke (cSt). A 30 weight oil will measure between 9.30 and 12.49 cSt when heated to 100 deg C. A 40 weight oil will measure even higher at that same temperature, and a 20 weight will measure less than 9.30 ct at the same temperature. Higher numbers mean a thicker, more viscous oil at the measured temperature. So, 5W-30 is a measured 5 weight oil when cold, and a measured 30 weight when hot. But, it's important to know that an oil gets thinner with increased temperature. Even though a 5W-30 is a heavier grade of oil when hot than cold, it is physically a thinner oil from the heat. So, a 30 weight is technically thicker than a 5 weight oil at the same temperature, and as the oil heats up, and the oil thins out, a 30 weight is still going to be thicker than a 5 weight at that same heated temperature even though it has thinned out with heat. An example of this with Amsoil 5W-30 and a 0W-30:

Amsoil 5W-30 pumping viscosity numbers at each measured temperature:
@40C= 55.8 cSt, @100C= 10.6 cSt

Amsoil 0W-30 pumping viscosity numbers at each measured temperature:
@40C= 56.9 cSt, @100C= 11.2 cSt

From the first number in the oil's weight, we know the 5W-30 is thicker than the 0W-30 when cold, since a five weight is heavier than a 0 weight. This means the 5 weight oil doesn't flow as well when cold as the 0 weight and the engine must work harder to pump it. When the oil heats up, the oil thins out. But, neither oil stays a 5 weight oil when hot- and for good reason! A 5 weight oil would be too thin when hot to protect the engine, with a cSt @100 deg C of less than 4 centistrokes. That would be too thin to do much good protecting the engine. Because the oil is a "multi-grade" oil, it contains a chemical additive package known as a viscosity index modifier or viscosity index improver. These additive packages react with heat to "thicken" up the oil so it behaves like a 30wt when hot. The 5W-30 has a cSt of 10.6 and the 0W-30 a cSt of 11.2 at 100 deg C. Each is obviously thicker than the 4 cSt a 5 weight oil at 100 deg would be. This multi-grade oil allows the engine a decent amount of protection that a straight 5 weight wouldn't be able to give, but with better cold start oil flow a straight 30 weight couldn't provide. In this respect, the Amsoil 0W-30 is a great oil because it flows better than the 5W-30 when cold but becomes thicker than the 5W-30 when hot for good protection. Notice that even at 40 deg C, the 0W-30 has already become thicker than the 5W-30. This is the beauty of multi-grade oils. It is also the reason that just because an oil is a 0W-xx weight, it should not be construed as a "thin" oil. The 0W-30 in this case becomes a thicker, more robust oil than the 5W-30 due to the great additive package Amsoil has endowed it with. Another example would be Mobil 1 0W-40. Same great cold weather and cold start protection a thinner oil has when cold, but becomes a 40 weight oil when hot.
For more information on oil viscosity, click here: http://theoildrop.server101.com/foru...e=0#Post711581 (http://theoildrop.server101.com/forums/showflat.php?Cat=0&Number=711581&an=0&page=0#Post711581)

Is a thicker oil better for engine protection than a thinner one?
Not usually, but sometimes. A thicker oil will have higher film strength than a thinner oil. Thicker oils tend to manage extreme heat beter, and as such are good for racing or FI engines. But, thicker oils create more drag in the engine and can cost you some horsepower and fuel efficiency. The general rule of thumb is to use as thin an oil as possible that still offers good protection from engine wear. The only way to see which oils do this is with a UOA, as discussed in the first post.

How do I know which oils are "thick" or "thin"?
There are two ways to see. First, check the bottle of oil you're considering. Look on the back for the oil's ratings. An oil that meets ILSAC GF-4 requirements is going to be a thin oil, and good for maintaining high fuel efficiency over oils that don't meet the requirement. Another rating to check for is the ACEA ratings. Oils that meet ACEA A1 and A5 requirements are thinner oils than those meeting the A3 and B4 specifications. Finally, API SM ratings are going to be thinner oils than those that meet the older SL ratings. Second, check the oil's viscosity you're considering on the following list. It is sorted alphabetically by manufacturer name. This list shows that not all 30 weight oils are the same at a given temperature, and the same for 40 weight oils, etc... Each brand has a different formulation that results in different pumping viscosities. From this list you can see what oils are "thick" or "thin" compared to others.
Also, you can see the HTHS score for some of the oils on this list. The HTHS score is the oil's viscosity at 150 deg C and refers to the oil's ability to withstand "High Temperature & High Shear" conditions. This is a good indicator of how well an oil will most likely hold up in a F/I engine, especially one with turbos. Higher HTHS numbers are better for extreme protection in such situations, and will also be thicker oils than those with lower HTHS scores.
Some oils also report the NOACK results as well. Lubricants with low NOACK scores lose less of their properties to volatility than lubricants with higher scores. Low-loss oils keep their original protective and performance qualities longer than high-loss oils do, which keeps oil consumption low and fuel economy and equipment protection high. It is also a good indicator of the base stocks used.

Amsoil ASL 5W-30 cSt @40C 55.8 @100C 10.6 HTHS 3.1
Amsoil Series 2000 0W-30 cSt @40C 56.9 @100C 11.2 HTHS 3.4 NOACK 8.6%
Amsoil Series 3000 cSt @40C 64.6 @100C 11.5 HTHS 3.5
Eneos 0W-20 cSt @40C 41.5 @100C 8.5
Eneos 5W-30 cSt @40C 58.1 @100C 10.4
Eneos 5W-40 cSt @40C 82.5 @100C 14
Eneos 0W-50 cSt @40C 104 @100C 18
Havoline Deposit Shield 5W-30 cSt @40C 59.4 @100C 9.7
Havoline High Mileage 5W-30 cSt @40C 74.8 @100C 12
Mobil 1 0W-30 cSt @40C 63.1 @100C 11 HTHS 3.0
Mobil 1 0W-40 cSt @40C 80 @100C 14.3 HTHS 3.6
Mobil 1 5W-20 cSt @40C 48.3 @100C 8.8 HTHS 2.6
Mobil 1 5W-30 cSt @40C 64.8 @100C 11.7 HTHS 3.1
Mobil 1 5W-30 EP cSt @40C 61.0 @100C 11.0 HTHS 3.1
Mobil Delvac1 5W-40 cSt @40C 102 @100C 14.8
Motul 300V Power 5W-40 cSt @40C 80.8 @100C 13.8 HTHS 4.5
Motul 8100 E Tech Lite 0W-30 cSt @40C 58.1 @100C 10.2
Motul 8100 E Tech 0W-40 cSt @40C 73.2 @100C 13.3
Motul Chrono 300V 10W-40 cSt @40C 89.5 @100C 14 HTHS 4.2
Pennzoil Platinum 5W-30 cSt @40C 59.7 @100C 10.5 HTHS 3.0 NOACK 12.5%
Pennzoil Platinum 10W-30 cSt @40C 63.4 @100C 10.5 HTHS 3.1 NOACK 9.7%
Pennzoil Platinum 5W-50 cSt @40C 106 @100C 17.8 HTHS 4.1 NOACK 13.3 %
Pennzoil Platinum 15W-50 cSt @40C 143 @100C 21.4 HTHS 5.1 NOACK 7.6%
QuakerState Q Advanced 5W-20 cSt @40C 46.5 @100C 8.68 HTHS 2.6
QuakerState Q Advanced 5W-30 cSt @40C 58.5 @100C 10.53 HTHS 3.0
QuakerState Q Advanced 5W-50 cSt @40C 109.5 @100C 18.7 HTHS 4.1
QuakerState Q European Formula 5W-40 cSt @40C 90.5 @100C 14.5 HTHS 3.9
Q High RPM 5W-30 cSt @40C 68.2 @100C 10.6 HTHS 3.1 NOACK 11.3%
Q High RPM 10W-30 cSt @40C 69.8 @100C 10.5 HTHS 3.2 NOACK 10.3%
Q High RPM 20W-50 cSt @40C 163 @100C 18.2 HTHS 4.8 NOACK 4.0%
Q Racing 0W-5 cSt @40C 15.2 @100C 3.56 HTHS 1.4
Q Racing 0W-20 cSt @40C 36.5 @100C 6.49 HTHS 2.2
Q Racing 17.5W-35 cSt @40C 101.2 @100C 12.7 HTHS 3.9
Q racing 15W-50 cSt @40C 144.8 @100C 18.45 HTHS 4.8
Redline 5W-30 cSt @40C 62.0 @100C 10.6 HTHS 3.8
Redline 5W-40 cSt @40C 94 @100C 15.1 HTHS 4.6 NOACK 6%
Redline 10W-30 cSt @40C 70 @100C 10.7 HTHS 3.8 NOACK 6%
Redline 10W-40 cSt @40C 93 @100C 14.6 HTHS 4.7 NOACK 6%
Schaeffer Supreme 9000 5W-40 cSt @40C 85.5 @100C 14.5 HTHS 4.6 NOACK 12.8%
Scheaffer Supreme 7000 5W-20 cSt @40C 43 @100C 8.5 HTHS 2.6 NOACK 13.86%
Scheaffer Supreme 7000 5W-30 cSt @40C 47 @100C 12 HTHS 3.2 NOACK 13.9%
Scheaffer Supreme 7000 10W-30 cSt @40C 62 @100C 12 HTHS 3.2 NOACK 13.57%
Shell Rotella 5W-40 cSt @40C 90 @100C 15
Silkolene Pro-S 5W-40 cSt @40C 92.4 @100C 14.9
Royal Purple 5W-20 cSt @40C 49.5 @100C 8.7
Royal Purple 5W-30 cSt @40C 65.3 @100C ?
Royal Purple 10W-30 cSt @40C 70.3 @100C 10.7
Valvoline Maxlife 5W-30 cSt @40C 62.3 @100C 10.61
Valvoline Synpower 5W-20 cSt @40C 46.9 @100C 8.65
Valvoline Synpower 5W-30 cSt @40C 61.7 @100C 10.9

Finally, here is a viscosity chart that I found to be very easy to read. If you have a UOA done and wanted to see how much your oil thinned out, you could compare it to the original grade of the oil in the list above, and then see where your used oil stands on this chart. As an example: One of the Amsoil 0W-30 UOA's had a viscosity of 11@ 100 deg C. According to the list posted above, Amsoil 0W-30 has a viscosity from the factory of 11.2 at this same temp. If the sample had come back with a 8.5 @ 100 deg C, then we could look at this chart and see that it was now a 20 weight oil, and probably not a good oil to continue using.

[Ghost]

Engine Oil Additives to the Base Stock
(or, why do some oils seem to work better than others?)

I talked in the first post about some elements that show up in a UOA are from engine oil additives that help protect the engine from wear. I also mentioned in the post about oil viscosity, that an oil can be a multi-grade oil thanks to additives known as viscosity index improvers. Engine oil additives are an important piece of the puzzle in understanding how one oil can do a better job protecting out engine than another oil. Most oils have about 10-20 % of their formulation in additives. These additives are what make up an engine oil's composition above the base stock used. A lot of chemical engineers and tribologists attribute an engine oil's additive package as more important in terms of performance than the base stock used. Base stocks are discussed in further detail later on, in post #6 in this thread. Some engines respond better to some engine oils simply because of the additives used in that particular oil. In order to really find which oils and the additives they use work best in the VQ, a UOA must be done- as discussed in the first post. Posted below is a list of the different additives and modifiers used in engine oils to achieve their respective traits. Some are more popular than others, and some are deemed better than others. In case you see some additive or property advertised in an oil, this is where you can see just what it does. As an example, if you find an oil that discloses a ZDDP additive, then it will probably be very good for protection of metals, but it also will lead to a shorter catalytic converter lifespan. Here is the exhaustive list taken straight from Molakule on BITOG:

Multifunctional Additives (in Alphabetical Order) listed as to Functional Agent, additive category, general or specific chemical compound, and how it works, respectively.

Antifoamants or foam inhibitors (Protective Additive): polymers such as silicone polymers and organic copolymers of the silaxane’s; creates a lens that reduces the bubble’s surface tension.

Antioxidants or oxidation inhibitors (Protective Additive): ZDDP, ZTDC, Moly TDC, Antimony TDC, aromatic amines such as organic tolutriazoles, thiadiazoles, diphenylamines, olefin sulfides, carboxylic acids; decomposes peroxides and terminates free radical reactions. Increases temperature of base oil at which base oil may tend to oxidize. Oxidation of oil promotes polymerization of sludge particles and increases viscosity.

Anti-Wear and Extreme Pressure Additives (Surface Protective Additive):
ZDDP, ZTDC, Moly TDC, Antimony TDC, Organic Sulfur-Phosphorus-Nitrogen compounds, Borates and Borate Esters, Tricresyl Phosphates, amine phostphates, and other phosphate esters, Chlorine compounds, and lead diamylcarbamates, lead and barium naphthenates, sulfurized olefins; protective film interacts at various temperatures and pressures to provide either a plastic interface or to provide a compound which shears at the surface.

Demulsifier (Performance Additive): hydroxyalkyl carboxylic esters, alkenlycarboxylic esters; keeps water separated from lubricant.

Detergents (Surface Protective Additive): metallo-organic compounds of sodium, calcium, magnesium, boron phenolates, phosphates and sulfonates such as alkylbenzene sulfonic acids, alkylphenol sulfides, alkylsalacyclic acids; Lift deposits from surfaces to keep them suspended.

Dispersants (Surface Protective Additive): Alkylsuccinimides, alkylsuccinic esters (alkenyl succinimides); chemical reaction with sludge and varnish precursors to keep them acid neutralized and to keep them soluble. Detergent-dispersants often are the same chemical or come in compounds to accomplish the combined function(s).

Emulsifiers (Protective Additive): Polyisobutylenesuccinimides, alkenylsuccinate ester/salts. polyester amides, alkyl aminoesters; promotes a stable emulsion or mixture of oil and water.

Friction Modifiers or Friction Reducers (Performance Additive): Organic fatty acids and amides, lard oil, high molecular weight organic phosphorus and phosphoric acid esters such as Tricresyl Phosphates, ZDDP, ZTDC, Moly TDC, Antimony TDC, family of diphenylamines and amides, and olefin sulfides. Reduces coefficient of friction formulated lubricant in the boundary lubrication regime. Some VII’s also provide friction reduction.

Metal Deactivator (Protective Additive): ZDDP, ZTDC, Moly TDC, Antimony TDC, family of diphenylamines and amides, and olefin sulfides, heterocyclic sulfur-nitrogen compounds; inhibits corrosive effects of oxygen with metals and decreases metal interaction with oxygen compounds to reduce oxidation of oil.

Oxidation Inhibitors (See Antioxidants).

Rust Inhibitor (Surface Protective Additive): Barium sulfonates, amine phosphates, phosphordithioates, sodium thizoles (for coolants),

Pour Point Depressant (Performance Additive): polymethacrylates (PMA’s); reducing wax crystal formation and increases solvency of oil at low temperatures. May be part of VII package.

Seal Swell (Performance Additive): nitriles, specific esters, organic phosphates and aromatic hydrocarbons. Increases volume of elastomeric seals.

Surfactants or Surface Active Agents (Protective Additive): family of diphenylamines and amides; usually part of the antioxidant package. Also provides enhanced friction reduction and allows oils to “climb” or spread on and over surfaces. Decreases but does not destroy surface tension

Soot Control or Soot Inhibitor (Protective Additive for diesels): Organic Barium compounds; keeps soot in suspension. Usually part of the dispersant package in diesel formulations.

Tackifiers (Performance Enhancement): copolymers of ethylene and propylene; helps oil cling to surfaces. Very useful in geared machines such as transmissions, differentials, and chains.

Viscosity Index Improver or Viscosity Modifier (Performance Additive): Olefin copolymers (OCP’s), hydrogentated styrene-diene copolymers, styrene esters, polymetharylates (PMA’s), mixed alkyl methacrylate-vinyl-pyrrolidines, aminated ethylene propylene, mixed alkylmethacrylate ethylene/propylenes; reduces viscosity change with temperature. Increases viscosity of base oil as temperature rises when base oil tends to thin. Some VII’s may also act as dispersants by incorporating dispersant compounds.

[Ghost]

Engine Oil Base Stocks
(or, what’s the diference between Group 3 and 4 oils, what’s a PAO, etc..)

The base stock is the main component an oil is made of, before any additives are incorporated to achieve the final product. Which base stock is used determines how an oil is classified. The primary base stocks are divided into five classification groups for engine oils:

Group 1- not really important here, it is the group that contains the least refined crude oil and not used in modern engine oils.

Group 2- This is the group that contains non-synthetic engine oils. The base stocks are made from conventional crude oils that have been refined to a point where it meets the standards set by the American Petroleum Institute for engine oil. Some conventional G2 oils perform as well as some synthetic oils because of the excellent additive packages used to fortify the base stock. Such oils (see the Castrol GTX UOA in the comparison charts in the first post for an example) are cheaper than synthetic oils and offer excellent engine protection. However, G2 oils typically cannot achieve the same viscosity spread as synthetics, such as an 0W-40 oil weight. They also cannot protect as well as synthetic oils when it comes to severe heat and stress conditions like racing or FI. Also, because they use a base stock that is not as refined as the higher grouped oils, they do not typically have the stability needed for the extended oil change intervals that synthetic oils can achieve. It is important to look at the UOA results of G2 oils and see which have performed well. The better performing G2 oils are a good buy for the owner who does not need an extended oil change interval, wants good engine protection, and likes to save some money.

Group 3- These oils are made from either a severely processed crude oil, slack wax feedstock, or either one of these blended with a Group 2 base stock. We’ll look at each separately:
1. Severely processed crude oils are known as “hydroisomerized” oils. They have recently been approved to market as a synthetic oil. Hydroisomerized oils have gone through an advanced distillation process to remove undesirable crude hydrocarbons (like wax) from the crude oil base stock. The theory is that since the oil has been so thoroughly distilled, and only the “best” hydrocarbons remain in the oil, that it might as well be a synthetic. “Hydrocracked” oils, as they are commonly called, are the most popular Group 3 base stock. Many companies use them for their synthetic oils, such as Castrol Syntec, Valvoline SynPower, the Motul 6100 “Technosynthese” formulations, Schaeffer’s 7000 line, etc... These oils tend to have NOACK scores 11% or higher for a standard 30 weight oil.
2. Slack Wax Feedstocks are the only Group 3 oils not made from crude. The most popular oils that I know of that use slack wax as a base oil are from Shell. The Rotella T-Syn 5W-40 and their Helix Ultra series use this base stock, as well as some Pennzoil Platinum oils as of last year. In fact, Shell has been able to use this base stock, with the appropriate VII additives and a blend of Group 4 and 5 oils, to make a 0W-70 oil (Helix Ultra 0W-70) for Ferrari’s F1 racing engines. Such viscosity spread used to be possible only with Group 4 oils. These oils are more popular in Europe it seems, and can be difficult to find in the U.S.
3. Synthetic Blends are oils that have a G2 base stock mixed with one of the above G3 synthetic base stocks, or a Group 4 or 5 base stock. An example would be Castrol Syntec Blend, which is a G2 oil blended with a Group 3 hydroisomerized oil. Adding the synthetic base stock helps the oil achieve a better HTHS score or maintain viscosity over the course of an oil change interval that a G2 oil couldn’t do on its own. These oils are slightly cheaper than full synthetic oils. They are becoming less popular now that hydroisomerized oils are now considered “synthetic”.

For even better performance, Group 3 synthetic oils may also be also fortified with fully synthetic oils from groups 4 and 5. Because of the addition of higher end base stocks from groups 4 and 5 in their formulations, these are sometimes referred to as Group 3+ oils. They may also be referred to as a breakdown of their group base stock blend, such as a G3/G4 blend, GIII/IV/V blend, and so on. Amsoil’s XL line of oils are in this category, as are some of Motul’s 8100 series like 8100 X-cess, Pennzoil Platinum, the Eneos economy oils, and there is strong evidence that most of Mobil 1’s line-up are also G3+ oils. G3+ 30-weight oils tend to have NOACK scores around 10% to 13%.
Group 3 oils are often criticized as not as good as oils from Groups 4 and 5. However, many tribologists say that the additive package and overall formulation is much more important than the base stock used when it comes to an oil’s performance. A strong case can be made for this by looking at the UOA’s posted on Pennzoil Platinum and Schaeffer’s. Both are in the top tier of the UOA results when it comes to engine wear numbers, without being a Group 4 or 5 oil.

Group 4- These are oils whose base stocks come from man-made hydrocarbons known as polyalphaolefins, or PAO’s. They are synthesized from ethylene gas, which is a byproduct of refined crude oil. PAO base stocks are prized for their flexibility in making oils with a large viscosity spread that perform well over a long oil change interval and under high stress. PAO oils are also more stable in the presence of water and moisture than Group 5 Esters. Some companies that offer PAO based oils are Amsoil, Mobil1, Royal Purple, Elf, and Eneos. These companies also offer oils made with G3 base stocks combined with a PAO. These are not Group 4 oils and are typically considered G3+ oils. In order to be considered a Group 4 oil, the base stock must contain no oil of a grade below Group 4. They must either be a full PAO base stock, or they may use a PAO base stock combined with an oil from Group 5, such as Esters. Examples include most Amsoil oils, Mobil 1 0W-40, Elf Excellium, Royal Purple, some of Motul’s 8100 line-up, and Eneos’ performance line-up. The high performance of the PAO base stock also lends itself well to high stress and high temperature conditions, such as racing. Many racing oils are some type of Group 4 oil, and typically also work very well for street driven cars that see track use or are running some type of forced induction. Group 4 30wt oils tend to have NOACK scores between 6% and 9%. However, just because an oil is a group 4, does not automatically make it superior. Some Group 3 oils have consistently outperformed Group 4 oils in the UOA’s. This, again, is why many tribologists believe finding the correct additive package is more important in terms of engine protection than the base stock oil, and why testing an oil is the best way to see if it is worth the money.

For Group 5 Base Stock oils, see post #8, as it exceeded the maximum characters allowed in this post.

[Ghost]

Group 5 This group includes Esters, Alkylated Napthalene, cycloaliphatics, silicones, silahydrocarbons, polyalkylene glycols, perfluoroalkylpolyethers, polybutenes, and any other fluids that do not fit in Group I, II, II, or IV. Esters and Alkylated Napthalene are the two most common, and we’ll look at each separately:
1. Esters are an aromatic hydrocarbon group found in many fruits and vegetables. They are most commonly used as flavoring agents in drinks, and for their characteristic smells in perfumes. Esters are defined by the presence of one carbon atom and two oxygen atoms attached to the end of a hydrocarbon molecule. Since we have already seen by now that not all hydrocarbons perform the same as an engine oil (hence the whole need for Group classification), it can be assumed that not all Esters function the same in terms of engine oil. There are some 600 known Esters, and manufacturers have found that some Esters can be synthesized from their natural resources and be very stable in extreme heat and stress, such as in a racing engine. The manufacturers that use a large Ester base stock are Motul’s 300V racing oil, Redline oils, Mobil 1 Delvac, and Silkolene. Most Ester based oils will have NOACK scores around 6% for a 30wt oil. Most Esters do well to help seal swell and condition seals. Esters also have a polar affinity to most metals, and this allows film strength under zero pressure. These qualities should lend themselves to excellent cold-start protection in addition to their ability to withstand high stress conditions. However, this is not always the case. In UOA’s on many engines that do not see any type of extreme stress, some Ester based oils perform worse than, or no better than, most Group 2 or 3 oils in the same engine. (See the UOA results of Redline 10W-40 in the comparison chart, it’s not bad, but not stellar either with high lead indicating excessive bearing wear). One possible culprit is an Ester’s tendency for hydrolysis. In the first post of this thread I mentioned how an oil’s base stock is degraded over time by oxidation, the result being more acids in the oil. The TBN number reflects this breakdown of an oil into acids. In an Ester base stock, these acids contribute to the break down of the Ester into an alcohol and a carboxyl acid. This process is known as Ester Hydrolysis. Hydrolysis is also created by an introduction of water or moisture to the oil. It is not an issue when the engine is running hard for most of its oil change interval, such as in a racing series. This is because there is enough energy in the form of heat to catalyze the reverse reaction, that is, to re-create an Ester from the alcohol and carboxyl acid made from ester hydrolysis. In an engine that sits idle, hydrolysis can be a factor, and the longer it sits the greater the problem. This is only one theory as to why Ester base stocks sometimes don’t perform better than other oils. The performance of Esters in an engine oil used primarily on the street is something of a mystery, and always controversial depending on who you ask. The issue is best summarized by a tribologist responding to my question of why Redline didn’t do that well in a UOA compared to other oils of “lesser” base stock:
Quote:
<table border="0" cellpadding="6" cellspacing="0" width="100%"> <tbody><tr> <td class="alt2" style="border: 1px inset ;"> I have posted a lot on RL - I do not consider it the “last word” anymore. Esters of course are also susceptible to hydrolysis, which is an issue with cars not driven often. I think a lot of ester “hype” gets into the rL picture, and that the verbage used 20 years ago may not apply today. Plus, RL’s formulations are “old”, and while tried and true with lots of Ca and ZDDP, th4ey do not post, as you pointed out, the numbers that indicate spectacular performance. I mean, esters should greatly reduce start-up wear due to their polar affinity, lubricity, film strength, etc. Yet, they are not much better (if at all) in wear reduction numbers than Chebvron/Havoline. I think there is much going on at the nanotribologic level that may be being missed, and that new formulations from companies with deeper R&D pockets than RL may be on to these wear elements. So the amines and other “new age” additives may be more than just an answer to the reduction in “old school” AW’s like ZDDP. I thought differently as late as last year, but have amended my thoughts and statements to conform to proof - the UOA’s of the latest “thin”, min-based GF-4’s, for example.

As I said, there may well be something going on at the molecular level (nanotribologic) at the surface level of the metal - I just have not seen the science, and esters in engines are so tiny in the pbig pciture that no one is doing the research. Esters are used in jets because of the temps involved - but that is exploited in RL advertising hyope, IMO. But RL looks so good “on paper” - why would it not “kill” all the others? Most racing oils use some amount of ester, but that can be to offset seal peformance issues of other synoil bases as much as to offer a perf benefit. </td> </tr> </tbody></table>
Also, the amount of esters used in the oil can vary greatly between group 5 products. Silkolene and Motul 300V both have around 20-22% Ester in their base stock, Delvac has about 26% Ester, and Redline uses a significantly higher amount of Ester, somewhere between 50% - 80%.
Different oils use different types of Esters, as well. Redline uses a Polyolester base oil, while Silkolene and Motul 300V both use Diester base oils. Some people feel that the reason Redline oils don’t do very well in most UOA results is because of the Ester type they use. This is a quote from a Silkolene chemist about their use of Diesters over Polyolesters:
Quote:
<table border="0" cellpadding="6" cellspacing="0" width="100%"> <tbody><tr> <td class="alt2" style="border: 1px inset ;"> In actual blends, the esters should not have to ‘fend for themselves’ when it comes to oxidation resistance at high temperatures; they are protected by efficient antioxidants. With the right antioxidants scavenging free radicals and protecting ‘beta hydrogen’, there is little to choose between equivalent diesters and polyol esters in automotive applications. In fact, diesters can have higher polarity, and higher VI than an equivalent polyol. High VI means that the ester contributes to the ‘multigrade effect’, so a smaller quantity of VI improver is needed. Remember, even the best VI improvers are shear prone to some extent, so replacing a proportion with totally shear-stable ester is a Good Thing. </td> </tr> </tbody></table>
Of course, Redline chemists defend the use of their polylolesters, and the final say should be what oil performs the best in your own UOA.
My opinion is that high Ester oils are better as a race oil, than a street oil. The real advantage an Ester has over PAO synthetics is shear stability in the face of extreme heat. That benefit is going to be realized best in racing, whereas the typical better performing wear protection of a good PAO in start/stop, short trip, and cold start stress will lend itself best to a street engine. High ester base oils like RL have to rely on the additive package more so to offset some of the negative aspects of the Ester base oil, such as moisture stability and elastomer compatibility issues, where a PAO basestock with additives makes a more street friendly oil. I think the value of these oils are best realized in twin turbo VQ engines, since they are seeing higher temps, and therefore the most important value for them is an oil’s HTHS score. Esters tend to have the highest. I think for daily-driven 350Z’s, a high Ester oil is a waste of money and not doing any favors for the engine. There is a lot of evidence to suggest A PAO/Ester or G3+/Ester blend base stock is an ideal set-up for daily driven cars that see track time. Some Motul 8100 series oils are this way, as is Eneos 0W-50, Silkolene Pro-S, and even Mobil 1 uses some Ester as a seal-swell additive . Of course, as I have already mentioned in this thread, only a UOA will really reveal how well an oil performs in your engine for your conditions.
2. Alkylated Napthalene is a less common base stock. It is a synthsized aromatic hydrocarbon used in mothballs. The Alkyl group is introduced to Napthalene and forms a stable polycyclic structure that can be used to stabilize oxidation in the oil. It is not used as a base stock by itself, but as a Group 5 additive to other base stocks. Alkylated napthalene resists heat and oxidation better than mineral oil, PAO, or diester, is hydrolytically stable unlike polyolester, has good additive solvency, and is more elastomer compatibile than esters. However, the napthalene complements rather than replaces the esters. An example would be Mobil 1, which is fortified with the addition of AN to its base stock formulation.

So what Group of oil is the best?
There is no single group that is the all-around best. It can be helpful to know what the differences in each group are, so that when someone says, “That’s only a G3 oil”, or “I only use Group 5 oils”, you’ll know what they mean. You should also realize by now that one base stock does not guarantee a better oil over an oil of a different base stock. There is far more to it. The proper viscosity, the additives used, the type of base stock, and the combinations of each are all different and all work together under some circumstances and in some engines better than others. Check for oil samples that consistantly perform well in the VQ, and then you will see a clearer picture of what works and what doesn’t. Better yet, get your own UOA done and check the reults in your own engine. Keep a running log of each oil you try and see for yourself what works.

[Ghost]

Feel free to add experiences you have had on this thread. Personally, I just changed my oil yesterday. I used the Penzoil Platnum and a K&N oil filter. So far the car is running great, and the oil is clear.

[rms0726]

Excellent posts Ghost. Could you e-mail or send me a link to the Used Oil analysis images. When I clickk on the thumbnails you posted the images were too small. When I copied them and tried to zoom in they were still unreadable. I'de like to see the charts if you still have the images. Thanks in advance-