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Discussion Starter · #1 · (Edited)
Several people on this site have had their oil analyzed and posted the results. I'd like to group those results into one easily searchable thread. (If one of the IWSTI admins would like to mirror the UOA's so the data does not disappear, that'd be even better!) I'd also like to add that I am not at all an oil expert, but I sure do like reading what the experts say. Again, the purpose of this thread is to serve as an index of UOA's.

What is a UOA?
Used Oil Analysis, or UOA's, tell how well your motor oil has functioned in your vehicle. By analyzing which particles of metal are in your oil, a UOA can reveal developing engine problems and provide clues into which parts of your engine are wearing.

How do I get one?
If you would like to have a UOA done on your oil, visit http://www.blackstone-labs.com and order the free test kit. Blackstone Labs charges $20 for the analysis and an extra $10 if you would like a TBN (Total Base Number), which essentially tells you how much life was left in your oil.

How do I read a UOA?
A UOA shows the elements in your oil in parts-per-million (PPM). Blackstone Labs provides this list of common elements:
Aluminum: Pistons, bearings, cases (heads & blocks).
Chromium: Rings, a trace element in steel.
Iron: Cylinders, rotating shafts, the valve train, and any steel part sharing the oil.
Copper: Brass or bronze parts, copper bushings, bearings, oil coolers, also an additive in some gasoline engine oils.
Lead: Bearings.
Tin: Bearings, bronze parts, piston coatings.
Molybdenum: Anti-wear additive, coating on some new rings (washes off as break-in occurs).
Nickel: Trace element in steel.
Manganese: Trace element, additive in gasoline.
Silver: Trace element.
Titanium: Trace element.
Potassium: Antifreeze inhibitor, additive in some oil types.
Boron: Detergent/dispersant additive, antifreeze inhibitors.
Silicon: Airborne dirt, sealers, gaskets, antifreeze inhibitors.
Sodium: Antifreeze inhibitors, additive in some gasoline engine oils.
Calcium: Detergent/dispersant additive.
Magnesium: Detergent/dispersant additive.
Phosphorus: Anti-wear additive.
Zinc: Anti-wear additive.
Barium: Detergent/dispersant additive.​
In addition, Blackstone Labs provides this diagram of reading an actual report:
http://www.blackstone-labs.com/eng_balloon_report_.html

The UOA will also detail the physical properties of the oil, the descriptions of which are provided in the sythetic/dino comparison below.

Understanding the Differences Between Synthetic and Dino Oil:

Synthetic oil has no peer when it comes to predictable and consistent lubrication. Even if the basic lubrication qualities were the same, the characteristics of synthetic oil that insure reliable performance cannot be denied. Let's compare:

Molecular consistency:
Organic: Multiple molecular lengths
Synthetic: Molecular configuration uniform.
Why important: Lighter organic molecules tend to evaporate in the heat of the engine environment, eventually losing up to 25% of the volume. The loss of the shorter (and more volatile) length chains alters the original composition of the oil, affects its flow qualities and temperature rating. Synthetic oils are "designer molecules". There are no smaller chains with no tendancy to evaporate under heat (see flash point below).

Flash point:
Synthetic oil burns at almost twice the Ferenheit temperature as traditional oil. It remains consistent under extreme conditions with no degradation, thinning, boiling or evacation from bearing surfaces due to vaporization. Temperatures that would severely degrade traditional oil does not affect the lubrication qualities of synthetic. Jet aircraft engines will not run on standard oil. Synthetic is required. Race cars and other high performance engines used to use caster bean oil for its superior qualities. Synthetic has replace caster bean for high stress environments.

Saturation:
Traditional oils are poly-unsaturated while synthetic oils are fully saturated. Traditional oils will combine with crankcase polutants to form new and unpredictable molecular compounds, severely compromising the viscosity rating of the oil. Synthetic oil, being fully saturated (no open chain molecular sites able to bind with other organic compounds) and are not affected by the presense of pollutants, bypass gasses, fuel dilution, or water.

Consistency:
Traditional oils are treated with viscosity modifiers to produce the traditional variable viscosity ratings (example: 10W40). Synthetic oil is designed to be a particular rating by virtue of its molecular configuration. Usage does not modify its performance whereas traditional oil gradually loses their additives. 10W40 becomes 10W30 over time, for example. Changing the oil every 3000 miles is a must to maintain consistency when using traditional oil. The extended changes recommended, mostly marketing in my opinion, are too long to insure that the oil is maintaining its designed qualities, let alone guarantee the filter is not bypassing. Wait that long and change your oil. Notice how much smoother the engine becomes after the change. Not a good sign.

Engine Cleanliness:
Traditional oil will form compounds with crankcase polution and recipitate deposits to the case of the engine. Synthetic oils cannot combine with crankcase chemistry and thus will not form sludge or other undesirable compounds to clog oil passages or retain dirt inside the engine. Because synthetic oils will suspend dirt and other chemisty, those particles have a greater chance of being removed by the filter.

Cold Weather performance:
Synthetic oil will flow at -60º F. where traditional oil is wax. Starting a synthetic oil equiped engine when it is 0º F. is like starting traditional oil when it is 40º. The engine runs effortlessly verses exhibiting the typical stress when using traditional oil at low temperatures. Cold weather operation before warm up is not nice on engine bearings and cylinder walls when the oil viscosity approaches jello.

Dirt:
Use a 1 micron aircraft quality oil filter and you might never have to change synthetic oil as it doesn't degrade. Traditional oil would stay just as clean, but would be compromised over time by chemical bonding altering its structure (see saturation above).

Expensive car manufacturers are not stupid:
BMW and other premium cars insist that their engines be lubricated with sythetic oil. BMW warns owners to change oil ASAP if anything else is used. Using synthetic oil with regular changes provides the level of protection to the engine that maximizes its life. Certainly, it is more expensive up front, but the benefits will be realized in smoother performance, higher gas mileage, lower oil temperatures, greater resistance to damage if a coolant system failure raises the engine temperature, and ultimately a lower cost of operation. We spend $20,000+ for a car and complain about spending an additional $10 every three months to protect this expensive investment. It doesn't make sense. Quality maintenance is part of the expensive of a car.
This information was originally posted by LGilbert.r


List of Subaru EJ25 (STI engine) UOA's:
Please note that these aren't all directly comparable to one another as different individuals drive their vehicles much harder than others. Lots of short trips in stop-and-go traffic on cold days can be brutal on an engine without the owner ever driving aggressively. In addition, things like oil and air filters make a difference; for example the cotton filter supplied with cold air intakes often do not filter as well as OE paper filters, and contaminants can show up in the UOA. The impact of a poor oil filter should be more obvious. I will also warn that oils showing great results on other (non-Subaru) engines will not necessarily perform well on the EJ25 engines. Of course, this all makes for great debate and discussion, and these analyses are here so that you may draw your own conclusions.

Please, if you have a UOA not listed here, post it below! (I'll update this list if I see it.)


Have a thirst for knowledge?
 

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Discussion Starter · #4 ·
WolfPlayer said:
If you want, you can provide my oil analysis directory. This directory is always up to date and I get an oil analysis on every oil change. The txt file in this directory tells the oil used and the interval.

http://www.bescaredracing.com/sti/oil/analysis/

t
Will do. I'm sure you've posted it before, but I didn't see it while skimming. Where do you get your Mobile1 racing oil? I've never seen it locally. It produces fantastic numbers and seems like a great choice for those running catless. Your UOA's are definately the best I've seen for the car thus far.

It's so interesting to me how differently oil performs on the STI than it did on my last car, a Mazda6. 0w20 oil worked incredibly well on that car, much better than heavier weight oils. It was speculated that the thinner oil was required to penetrate the tight bearing clearances. The lower weight oil has been found to improve UOA's on some very aggressive engines, too. However, people here seem to freak out at lower weight oils, reporting very high oil consumption. I'd be curious to see a UOA on Mobile1 5w20.
 

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Discussion Starter · #6 ·
Thanks BlueGold. List updated, 15 UOA's in total.
 

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stretch said:
Will do. I'm sure you've posted it before, but I didn't see it while skimming. Where do you get your Mobile1 racing oil? I've never seen it locally. It produces fantastic numbers and seems like a great choice for those running catless. Your UOA's are definately the best I've seen for the car thus far.

It's so interesting to me how differently oil performs on the STI than it did on my last car, a Mazda6. 0w20 oil worked incredibly well on that car, much better than heavier weight oils. It was speculated that the thinner oil was required to penetrate the tight bearing clearances. The lower weight oil has been found to improve UOA's on some very aggressive engines, too. However, people here seem to freak out at lower weight oils, reporting very high oil consumption. I'd be curious to see a UOA on Mobile1 5w20.
You mentioned oil consumption. What is causing it? Is it a common problem with our cars? I am also wondering, say if I am currently using dino oil and my car does not consume any oil does it mean that it will not consume if I switched to synthetic?
 

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Discussion Starter · #8 ·
Keep the UOA's coming, guys. I've added a few since my last post in this thread.
0bluesti4 said:
You mentioned oil consumption. What is causing it? Is it a common problem with our cars? I am also wondering, say if I am currently using dino oil and my car does not consume any oil does it mean that it will not consume if I switched to synthetic?
The switch to synthetic shouldn't cause consumption so long as you're using oil with the same viscocity.

As to what causes oil consumption, that's a much bigger question that I don't think I can answer. Pistons usually have three seals, each wiping some oil off of the cylinder sleeve while leaving enough to lubricate the following seal. Some oils seem to penetrate the combustion chamber and burn off. I'm not sure how bad this is so long as you monitor your consumption.

Mobil1 oil is rather thin for its rated viscocity, and some have reported high oil consumption with it. However, its sheer resistance is better than many higher viscocities. Low viscocity is good so long as it resists sheering, so while some report their engine consuming a lot of Mobil1, their engine may still be wearing better than with a higher viscocity oil.

Most people here will say that turbo engines tend to consume some oil, moreso than a naturally aspirated engine. I'm not sure why this is- sure the engine is tuned more aggressively, but the seals are the same.

I've read that oils designed for high-mileage engines have addivites that prevent the oil from burning off. Is that really a good thing? If so, I wonder if that would be appropriate for the STI, allowing an otherwise lower viscocity.

Again, perhaps someone else can answer with more detail. I want to stress that I'm not an expert on this stuff!
 

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After I saw that I had high silicon I found that my turbo inlet was torn, so I got that replaced. This was after 5 months of mainly city driving. Using oem oil filter and air filter.
1,155 mile= RP 10w30
985 mile= Valvoline 5w30 dyno
 

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Seems pretty common for Royal Purple to shear down a bit. I don't see any reason for you to run a year with the same oil with the low miles you do, both oils obviously did a great job.
 

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Amsoil 10w40 3100 miles

Here is a report for Amsoil 10w40 Full Syn:

10w40 Amsoil 3100 miles

This was after 4 or 5 autox events in 100-115 degrees on the OEM oil filter.

Not sure why my silicone is high. Can't find any intake leaks and my OEM air filter looks fine (has about 12k on it). Engine has never been cracked open. I will get another analysis next oil change to see if it goes down.
 

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#4 OCT 2009
Castrol GTX 5w30
K&N oil filter
K&N OEM size panel filter

#3 DEC 2008
Castrol GTX 5w30
Subaru oil filter
K&N OEM size panel filter

#2 OCT 2007
Castrol GTX 5w30
Subaru oil filter
K&N OEM size panel filter

#1 DEC 2006
Quaker Advanced Synthetic 5w30
Mobil 1 (M1-108) oil filter
K&N OEM size panel filter

 

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My highly modded car consumes oil so I told my STI "F#$% U" and started giving it Walmart Supertech synthetic oil, 5w30. I plan to send it in to see how my $13.54/5 quarts holds up to the name brands.

I'll post some results in about month.
 

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here's my oil report: used valvoline 5W/30 SYNTech, i've been using this oil for about the last 10K miles......

 

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^Same here. Just ordered my oil analysis kit.
 
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