API Oil test Comparo

[Cobra'03]

These are the most comprehensive and recent ones I could find. They date to March 2003 and May 2003. I will post the numbers, add a comment or two, and answer any questions you may care to pose. These tests were commisioned by Amsoil, but since they use standardized ASTM protocols, they could easily be verified, and any deception challenged. Based on my experiences with the products from all these companies, and the results of similar but less comprehensive tests posted elsewhere, these do not look doctored or suspect. But as I did not oversee them, I cannot and will not be accountable for any discrepancies, real or imagined. This was a lot of work to type, and I strived to get them right.
BTW, RR stands for "Road Rage", my handle on some other car forums.

1. All the oils were 10w30 viscosity
2. The oils tested were:
Amsoil (syn)
Castrol GTX Drive Hard (mineral)
Valvoline Synpower (syn)
Mobil Drive Clean (min) - isn't this the rebadged Honda oil?
Pennzoil Purebase (min)
Quaker State (Syn)
Quaker State Peak Perf (min)
Castrol Syntec (syn)
Valvoline (min)
Pennzoil Synthetic (syn)
Mobil1 SuperSyn (syn)

The following ASTM tests were run:
Thin-film Oxygen Uptake ( D-4742)
High Temp/High Shear ( D-4683)
NOACK Volatility ( D-5900)
Pout Point (D-97)
Total Base Number (D-2896)
Cold Cranking Simulator D-5293)
4-Ball Wear (D-4172)
*********************************************************
Test 1: Thin Film Oxygen Uptake:
Measures the oxidation stability of an oil.
The induction time (break point) in minutes is measured. The test uses standard amounts of fuel dilution, soluble metals, and water to offer a real-world applicability.

Results for this test(all units in minutes):
Amsoil: >500 (no break)
Mobil1: 397
Pennzoil Purebase: 242
Castrol Syntec: 221
Valvoline: 219
Vavoline SynPower: 211
Mobil Drive Clean: 209
Quaker State Peak Performance: 192
Pennzoil Synthetic: 159
Quaker State Synthetic: 159
Castrol GTX Drive Hard: 132

Test 2: High Temperature/High Shear (HT/HS)
Measures a lube's performance under severe heat and shear (mechanical stress) as would be found in the journal bearings under heavy load. The units displayed are viscosity based, using the centipose unit (cP). The minimum spec for a 30w is 2.9 cP.

Results for this test (all units in cP):
Amsoil: 3.51
Quaker State Peak Performance: 3.37
Castrol GTX Drive Hard: 3.35
Vavoline SynPower: 3.30
Mobil1: 3.30
Valvoline: 3.30
Mobil Drive Clean: 3.28
Pennzoil Purebase: 3.16
Quaker State Synthetic: 3.15
Pennzoil Synthetic: 3.14
Castrol Syntec: 3.13

Test 3: NOACK Volatility.
Measures the evaporative loss of lubricants in high temperature conditions. The higher the number, the thicker the lubricant will become. API SL and GF-3 specs allow for a 15% evaporation limit. In this test, obviously, lower is better. Syns almost always have an advantage due to their monomolecularity.

Results for this test (% weight loss):
Amsoil: 4.86
Vavoline SynPower: 7.03
Castrol Syntec: 7.77
Quaker State Synthetic: 7.80
Pennzoil Synthetic: 8.15
Mobil1: 8.92
Castrol GTX Drive Hard: 8.93
Quaker State Peak Performance: 10.63
Mobil Drive Clean: 10.83
Pennzoil Purebase: 10.93
Valvoline: 12.18

Test 4: Pour Point
This test reveals the lowest temperature at which a lubricant will flow when cooled under test conditions. The lower, the better the product will perform in getting from the oil pan to the upper oil galleys, and in providing oil pressure quickly. Synoils generally are the best, because they are free of wax crystals, but today's mineral oils are better refined to remove wax impurities, and use advanced pour point depressant additives to help offset the synoils' intrinsically better properties.

Results for this test (all units in degrees Centigrade):
Amsoil: -48
Mobil1: -46
Vavoline SynPower: -46
Castrol Syntec: -43
Pennzoil Synthetic: -40
Quaker State Synthetic: -40
Pennzoil Purebase: -37
Valvoline: -37
Mobil Drive Clean: -37
Castrol GTX Drive Hard: -37
Quaker State Peak Performance: -34

Test 5: Total Base Number (TBN)
TBN displays the lubricant's reserve alkalinity, and is, of course, the opposite of TAN (total acid number). A high TBN will help resist the formation of acids from sulfur and other sources. It is also a good indicator of reserve resistance to oxidation. The higher the number, the superior ability to suspend contaminants and the greater the ability to provide long-drain intervals
Results for this test (all units in mg KOH/g):
Amsoil: 12.34
Vavoline SynPower: 11.38
Castrol Syntec: 10.39
Pennzoil Synthetic: 9.73
Mobil1: 8.57
Valvoline: 7.88
Quaker State Synthetic: 7.82
Castrol GTX Drive Hard: 7.74
Mobil Drive Clean: 7.71
Quaker State Peak Performance: 7.55
Pennzoil Purebase: 7.40

RR's comments: I was very impressed with all the oils, as the mineral oils have significantly improved, consistent with previous comments about how mineral oils are closing in, and that the GF-3 spec has resulted in very good performing products. Mobil1's showing is the best i have seen for that product, which usually was in the 5-6 range previously. It certainly also supports my previous comments that the 3K oil change "necessity" is out of place with current technology. Like an enema for a dead man, while it may not help to do a 3K change, it wouldn't hurt I guess.

Test 6: Cold Crank Sumulator
This one determines the apparent viscosity of the oils at low temperatures and high shear rates, simulating the dreaded cold start. It has direct applicability to engine cranking, the lower the number the better in terms of stress on the battery, starter, etc. A 10w is tested at -25degF and must show a vis <7000 cP to pass.

Results for this test (all units cP at -25degC):
Pennzoil Synthetic: 3538
Amsoil: 3590
Mobil1: 3967
Quaker State Synthetic: 4142
Vavoline SynPower: 4541
Quaker State Peak Performance: 4620
Castrol Syntec: 4783
Castrol GTX Drive Hard: 5804
Pennzoil Purebase: 5936
Mobil Drive Clean: 6448
Valvoline: 6458

RR Comments: If you live and drive your car in very cold climates, the advantage of the synoils is obvious. Keep in mind that the NOACK performance figures here as well, as this tests hows the performance of fresh oil - after a few thousand miles, the oils with higher volatility will likely have thickened, unless there has been high dilution from fuel, such as can occur if excessive startup idling warmups are employed.


Test 7: Four Ball Wear
This one is a good indicator of the wear protection of a lubricant, although in the real-world it is should be factored in with the TBN of the oil. Three metal balls are clamped together, and a rotating 4th one is pressed against them in sliding contact. A scar is produced, since at some point the film strength (resistance to being squeezed out) of the oil will be exceeded. The scar is then measured, and the smaller the average wear scar, the better. This test is affected by both the base stock of the oil, and its additive package.

Results for this test (all units in inches):
Amsoil: 0.40
Castrol Syntec: 0.45
Vavoline SynPower: 0.55
Quaker State Synthetic: 0.55
Mobil Drive Clean: 0.55
Pennzoil Synthetic: 0.60
Mobil1: 0.60
Valvoline: 0.60
Castrol GTX Drive Hard: 0.60
Quaker State Peak Performance: 0.60
Pennzoil Purebase: 0.65


RR Comments: Amsoil and Castrol Syntec are the clear frontrunners, indicating excellent chemistry and use of anti-wear additives. Once again, the high performance of the mineral oils against the 2nd tier synoils is notable, although one cannot dismiss the superiroity of the synoils across the board.

**************************************************************

Final comments:
I think that except for one of the lubes, there was a wide discrepancy of performance for the others - one might be good here, not so good there. As in life, consistency of performance is what sets apart the great from the good.
As Voltaire said, "The best is the enemy of the good". Perfectly good performance can be found in any of these products, and a thinking owner would factor his/her driving styles, operating conditions (environmental), maintenance schedule (intervals between changes), cost constraints, buy vs lease, and expected length of ownership into making a choice.

Now, what about the other top synoils? Well, they were not tested here, but certainly the industry giants were. Based on tests I have run or seen from sources I trust in the industry, Red Line, NEO, Motul, and others would likely score in the top quartile of these tests. The tests anmd UOA's I have seen for Royal Purple have never shown it to be other than mid-tier, competitive with the synoil or GIII mineral oils from the major companies.

Hope this is useful to you - I found it fascinating to watch the goo go head to head.

Happy Motoring!!

 

[esqeddy]

Wonderful data. Looks like running a synthetic oil is a real consideration.

So....enquiring minds want to know....what oil are you running in your 03 Cobra?

 

[PhillyCobra]

Cobra'03--

Awesome, as usual!


One question I have, having used syn oil exclusively for 12 years except for my new Cobra, is seal longevity. Had oil pan seal go brittle (along with other areas of seepage) with Mobil1 on my 1996 Duratec Taurus after 70,000 miles-- tightened up with one run of the Valvoline oil for older engines (has some kind of gasket softener).

Is gasket life any issue anymore? Or are newer gaskets more durable, or syn oil more conducive to gasket life?

 

[mosconiac]

Thanks Cobra'03...another great post!

Not that I ever doubted the decision, but it is nice to see my Amsoil is going to treat my '03 very well. Thanks for educating me.

To bad they didn't test RP, since I'd love to see how the "miracle lube" would do in comparison.

 

[predator]

WOW....good stuff as usual. I had been thinking of switching to Amsoil, since I had just hit 5K. Interested how other fluids like tranny and diff have come along too.

 

[mswaim]

I think I'll stick with my Valvoline Syn. The ratings look good and the price is much better than Mobil 1.

 

[Cobra'03]

Originally posted by predator
WOW....good stuff as usual. I had been thinking of switching to Amsoil, since I had just hit 5K. Interested how other fluids like tranny and diff have come along too.

Can't fault that - it is a fine product. And it has done very well in the UOA's (used oil analysis) in terms of low wear rates.

 

[03 Wave Bye]

Great Information:beer:

 

[TOC]

Thanks for the good info

 

[NukeX]

Someone tell me, if I run mobil 1 5w-30 is my shit going to blow up now at 50k miles???? does mobil 1 sux? Shit i dont know, i know AMSOil is better lol will it harm my engine to go from mobil 1 5w-30 to AMSOil 5w-20?

 

[PhillyCobra]

Cobra'03,

Another question, besides gasket sealing one:

As most engineering decisions involve compromises, is it possible that Amsoil does not do as well in certain other areas that they didn't publish, as opposed to its general superiority in the areas presented? Or is its only disadvantage its high cost?

 

[JKD COBRA]

very good info, I will have to look into Amsoil instead of Mobil1.

 

[FastCobra]

For those of you running Amsoil, what is your oil change interval? They say 1-year or 25,000 miles Or if you go with the series 2000 oil, its good for 1-year or 30,000 miles.....of course change out the filter at 6 months.

 

[Cobra10thaniv]

Originally posted by PhillyCobra
Cobra'03--

Awesome, as usual!


One question I have, having used syn oil exclusively for 12 years except for my new Cobra, is seal longevity. Had oil pan seal go brittle (along with other areas of seepage) with Mobil1 on my 1996 Duratec Taurus after 70,000 miles-- tightened up with one run of the Valvoline oil for older engines (has some kind of gasket softener).

Is gasket life any issue anymore? Or are newer gaskets more durable, or syn oil more conducive to gasket life?

Lots of the gasket materials are much better & now made of such things as Viton and many others. Although where as before your local napa usually carried better gaskets than factory not true always now. I have founds GM statement true keep GM GM Many times now I returned gaskets sets due to poor design and or materials. Yes they would have sealed but for how long who knows. Thats why I have now been going back to the dealer for OEM gaskets.

With warranty issues being a cost factor I believe all the car companies experienced what ford did and went back to or tried to do the ford quality is job 1 !

So to answer your question I dont believe gaskets quality is a issue any more. Like running the 10% ethonol mix in gas. But i couln't say for sure. Most things today are life limited designed. To be on the road for only so many years. So use of high quality may not be used even though availiable.

 

[99Blkcobravert]

Amsoil XL7500 is the 5w-20 oil spec'd. It has a normal drain interval of 7500 miles. REMEMBER to use the AMSOIL filter too, it filters out 4 micron particles...no one else does this well.

 

[Cobra10thaniv]

Originally posted by 99Blkcobravert
Amsoil XL7500 is the 5w-20 oil spec'd. It has a normal drain interval of 7500 miles. REMEMBER to use the AMSOIL filter too, it filters out 4 micron particles...no one else does this well.

Lots of people are to up on micron size. A main thing about a micron stated size is to see if they say MPE or SPF if its MPF IMO with the background I have always used this as advertising hype.

What counts is SPF not MPF (MULTI PASS EFFICIENCY)what the filter will do after circulating for 1000 miles and get the micron size down. Damage is done if your flowing large size micron garbage threw your bearing journals.

By chance do you know what they state there as. As a rule I have found

1. not listed and no data can be found well its not a good filter.

2. If micron size is listed but they cant find out if its MPF or SPF it is mpf not bad filter but allot better than filter #1

3. SPF listed and 10 micron you might check to see if what MPF is on that filter you might find out that its as low as 4


MICRON SIZE
There is no standard the filter companies go by when stating what their filter micron size is, Like most would like to think there is an international standard.

Best filter media most always is the glass type element,Why? Because they can control how the glass media is laid for micron size.

Back to micron size and the statement of no standard and what’s the difference of 10 micron 10 is 10 right? Well no, think about an arrow try to about that going threw a filter sideways can’t but if it’s a direct it could be smaller than 10 micron yet larger than 10 micron if placed the other way.

This is where the problem with the micron standard falls apart with many companies. It all depends on how they want to test their filter and what type of contaminants where sharps or round or spear like from a bearing shaving. There is no standard.

As a rule you normally get what you pay for. If it cost more and is of good construction media in the filter such as glass you’re on the right path

Sorry for being so long winded but I have gone through this at work with a million dollar lasers and other such equipment. I wanted everyone to understand about this micron size.

 

[Cobra'03]

Originally posted by NukeX
Someone tell me, if I run mobil 1 5w-30 is my shit going to blow up now at 50k miles???? does mobil 1 sux? Shit i dont know, i know AMSOil is better lol will it harm my engine to go from mobil 1 5w-30 to AMSOil 5w-20?

PAO has been known to shrink some seal materials, but that has been adressed years ago, by the addition of small amounts of esters, which tend to swell seals, or by the addition of seal swell/shrink technology as someone mentioned a few posts earlier in products like Valvoline MaxLife. So I would not be concerned about that at all. In 1976, when Mobil1 started to gain popularity, it got a bad rap that it was "too slippery to stay in the engine" and all that nonsense. In fact, it was the seal shrinkage mentioned earlier. Plus, advances in seal material like Viton, and the increased use of relatively inert materials like RTV have all but elminated the problem. As did Chevy when it finally went to a one piece rear main seal, which Ford had had for years.

Regarding your Mobil1 1 question - read carefully what I wrote. All of the oils perform very well, and M1 is a solid mid-tier performer at an attractive pricepoint, widely available, and compatible with practically any seal out there because of its widespread use. You will not see me post anything as retarded as the stuff you often see on these Websites - "M1 is crap" or "Royal Purple is da nutz". Do not focus on just one parameter - the Amsoil is a prestige product at a prestige price, as are Red Line and Motul. And who knows if the new Series 2000 Amsoil is better still? Time will tell.

I have long thought about developing a spreadsheet that has dynamic weightings and such - you answer a number of x,y,z questions that determine your use (street, race, drags), your change interval (short or extended), etc. and then using lumped sum parameter tabulation, you get a recommendation.

 

[Cobra'03]

Originally posted by Cobra10thaniv
Lots of people are to up on micron size. A main thing about a micron stated size is to see if they say MPE or SPF if its MPF IMO with the background I have always used this as advertising hype.

What counts is SPF not MPF (MULTI PASS EFFICIENCY)what the filter will do after circulating for 1000 miles and get the micron size down. Damage is done if your flowing large size micron garbage threw your bearing journals.

By chance do you know what they state there as. As a rule I have found

1. not listed and no data can be found well its not a good filter.

2. If micron size is listed but they cant find out if its MPF or SPF it is mpf not bad filter but allot better than filter #1

3. SPF listed and 10 micron you might check to see if what MPF is on that filter you might find out that its as low as 4


MICRON SIZE
There is no standard the filter companies go by when stating what their filter micron size is, Like most would like to think there is an international standard.

Best filter media most always is the glass type element,Why? Because they can control how the glass media is laid for micron size.

Back to micron size and the statement of no standard and what’s the difference of 10 micron 10 is 10 right? Well no, think about an arrow try to about that going threw a filter sideways can’t but if it’s a direct it could be smaller than 10 micron yet larger than 10 micron if placed the other way.

This is where the problem with the micron standard falls apart with many companies. It all depends on how they want to test their filter and what type of contaminants where sharps or round or spear like from a bearing shaving. There is no standard.

As a rule you normally get what you pay for. If it cost more and is of good construction media in the filter such as glass you’re on the right path

Sorry for being so long winded but I have gone through this at work with a million dollar lasers and other such equipment. I wanted everyone to understand about this micron size.

Not long winded, just well thought out! I agree with this - at some point, micron size becomes irrelevant for another reason - the gaps ion the internals are just not that small. Dirt is realy dangerous when two particles get side by side, because they will force each other against, say, the cylinder wall or the oil ring land or piston skirt and scratch. But once yopu get really small, they just happily travel around in the oil, suspended by the additive chemistry until they are removed either by the filter or by the oil drain. Capacity, efficiency, and integrity of the filter media are as important or even more so than sheer micron spec.

 

[Cobra10thaniv]

Originally posted by Cobra'03
Not long winded, just well thought out! I agree with this - at some point, micron size becomes irrelevant for another reason - the gaps ion the internals are just not that small. Dirt is realy dangerous when two particles get side by side, because they will force each other against, say, the cylinder wall or the oil ring land or piston skirt and scratch. But once yopu get really small, they just happily travel around in the oil, suspended by the additive chemistry until they are removed either by the filter or by the oil drain. Capacity, efficiency, and integrity of the filter media are as important or even more so than sheer micron spec.

Correct the flow rate of the filter is very important or as important maybe more if you look at the filter goes into bypass mode if it cannot flow in cold conditions until oil is warm. Your right you have to look at everything and they type of use you have.

Maybe the Cold factor isn’t a factor for a person at all. Where the filter is great, but bypasses when cold because it cant flow with that SPF with oil that thick. But you never run it in this environment.