Comparison oil tests of 10w30 for S2000

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.

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)
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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.

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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!!

Excellent post and info, think I'm switching oil brands...and yes, Honda oil is re-badged Mobil Drive Clean, so if the dealer does your service, this is what you get.

I'll continue to use Mobil 1, if it's good enough for a factory fill in 100K Porsches, AMG Benz and Vettes.. good enough for me..

Priceless info IMO from an unbiased adept in the industry.
Thank you sir for your time and attention!

IMO, Amsoil is biased and a bit shady. Besides their multi-level marketing scheme that reminds me of Amway, they also sell nurtrional supplements, fertilizers, water filters, and other home care products. Hmmmm...I'll stick with Mobil. Road Rage, I do thank you for compiling the data though. That was a lot of work.

Jeez, thanks for typing all that. But, darn it, you've made me rethink things.

So, my car always goes for a drive of a minimum of 30 minutes, I live in a moderate climate in the Pacific Northwest, not too hot, not too cold, I don't drive the car on the ragged edge, and I drive in very little stop and go since it's a weekend cruiser.

From what you say with an oil like say, Amsoil, I could easily go 7K/one year between changes. I'd change the filter at 3750/six months because I couldn't deprogram myself from wanting to do something. Sound good? Not holding you to anything and I don't have a lawyer.

Again thanks for all the input you're giving us.

edited by XV

This post has been edited by xviper on Aug 18 2004, 07:56 PM

Thanks for the report, it was very informative. I think I will be Driving Clean for a while with Mobil. Oh, by the way the Mobil Drive Clean Oil had a stronger petroleum smell than the Honda 10-30 Oil. It may just be the batch of oil processed.

Mobil1 is a good product, mid-tier in all the tests.

I don't care for Amsoil's marketing model either, and I have posted before that early on, they got nailed for selling 55 gal drums of syn gear lube that were not quite up to snuff. Their multiple products lines do not bother me at all. GE sells refrigerators - does that make their jet engines bad?

This is sort of a red herring argument - indicting the product for issues that have no relation to it. The facts of the tests speak for themselves, and as I already commented, it is corroborated by both independent analyses I have run over the years myself, results from others I trust, and can easily be impeached if someone wants to run other tests.

The gear lube test I posted a while back was run by an independent laboratory with unimpeachable credentials, and it showed their gear lube at 3X the test sequence performing better than Valvoline NEW.

I do not fault your choice, just your line of reasoning.

P.S. I have held Amsoil's feet in the fire before - on Acura-TL: website, I think I was one of the first to point out that their XL-7500 product was not a PAO synoil, but a product of the Castrol Lawsuit GIII redefinition. They later become "clearer" about the distinction. So I have no predisposition to like or not like the products. I have absolutely no financial links or stake in the game. In my Corvette business, I sell RedLine, Amsoil, Motul, Valvoline, Pennzoil, and others.

I think that maintenance plan is perfectly sound - run a yearly used oil analysis if you have any doubts.

I could have sworn I posted that info...perhaps I am losing my mind? Look at 2,3,6. The others are obviously relative and no min std is known to me.


And I do not live and die by API SL - I posted previously that many tribologists are not sure that the lowered levels of phosphorous demanded by the mfr's to protect their catalytic converters will provide the same level of wear protection as non-API certfied oils like Amsoil and Red Line. The GF-3 compliant oils used a new generation of anti-wear additives, but look at the huge gap between Amsoil and the others. The mineral oils in the wear test must all be buying the same AW additives packages from outfits like Lubrizol.

Good report RR. Reminds me of the days when I was working at Castrol doing oil trials. Road rage do you know of any trials that have taken place where many oils were tested in any kind of engine and cylinder wear data was collected ? Still looking for this info on the net.

Rich.

No. You might check the SAE research librarian. Mobil did one on its own product, and it showed little wear at 200k miles - so extrapolate that and imagine what an oil that measures better might do?

Over the road haulers using Amsoil and bypass lubricant have gone 1 million miles. Mny truck mfr's will warrant their trannies/diffs for 1 million miles if they using approved synoils - the drain and fill plugs are replaced with no tamper types!

Some of the new BMW automatics come with no fill plugs!

BTW, Volvo has designed a car for women - a team of women engineers and product developers worked on it. It calls for 30,000 mile OIL change intervals! It is essentially maintenance free, and transmits to the dealer a service call when needed. Hard to believe, no?

And Visteon has a 150k air filter design.

Nope. But GE uses an entirely different business model than Amsoil. I do not feel it is a good comparison. GE has segregated itself into many prodcutive businesses. Somthing tells me they won't be pushing their jet engines on me if I order a refrigerator. I can also go to the closest home improvement strore to pick up a GE refrigerator whereas there is no auto store to my knowledge in a 30 mile radius of my address that carries Amsoil products. And if Amsoil was so great and so wonderful, like GE refrigerators, shouldn't it be falling off the shelves anywhere I go?

Let's examine my reasoning so far. A company that has shady marketing practices and wants me to void my manufacturer's warranty by going 25000 miles between oil changes....it's pretty clear to me.

interesting

Road Rage, sir you are a most welcome member of the s2ki community. thank you very much for this comprehensive information and analysis!

This is excellent information - thank you very much for compiling it! Here's one vote to make this a "sticky thread" at the top of the page.

oh and let me go ahead and sum up all that mumbo-jumbo for us S2000 fanatics

If you love your S and plan on keeping it forever, PURCHASE AMSOIL BY THE CASE.

(do I hear Group Buy?)

The way a product is marketed is not a concern to me, nor should it be to anyone. The bottom line is performance. If it gets the job done and does it the best, that is what you should consider relevant. If a company wants to distribute their products through a multi-level method, who cares.

I use Mobil 1 because it's more accessible. But based on my findings Amsoil is the best.

Good information. Thanks for taking the time to collect and post it.

Thanks for reporting the test results. I understand the need for controlled tests and comprehend the findings but question that they correlate to real world results. It is my belief that we will not see any difference with regular oil changes using any of these products.

Do you know if the Amsoil oil tested was the regular synthetic or the XL-7500 syn? What is the diff. between the two?

I also use Mobil 1 Sup syn. It works great. Don't plan on switching either.

Do what you will but Mobil is definitely inferior to AMSOIL.

Then use what I use, Redline.