540 RAT

A few words before getting into the oil test data. Most Forum members have understood and appreciated the oil test data I've posted over the last year and a half or so. But, there were always some who could not accept my results that showed high zinc levels were not always something that could be counted on for superior wear protection. So, there was a lot of hostility over that. And honestly, I can understand why some folks might have a problem with my data showing that. Because for the past couple of decades, the whole Hotrod and Racing Industry did nothing but promote how wonderful high zinc levels were, which may well have been true many years ago when zinc levels first began getting significantly reduced in API certified oils. Therefore, reluctance to accept a wholesale change in thinking is not surprising, even though there are much better alternatives used in low zinc API certified oils nowadays.

The folks who could not accept my data, also seemed to get the wrong idea about it. If the oil they preferred did not rank very high on my list, and they had never had a problem using it, I never said they needed to stop using it. If they had good success with what they use, that meant they were not exceeding the capability of that oil. As long as they continued to stay below that oil’s capability limit, they would never have a problem. But, if they wanted to choose a better oil, for extra wear protection insurance, all they had to do was look at my ranking list and choose a higher ranked oil. In spite of any previous skepticism regarding my testing, we should now be able to put those issues behind us, and move forward on common ground, as one group on the same page. Here's why:

I'm a total perfectionist when it comes to technical matters. I'm a working Professional Degreed Engineer, as well as a U.S. Patent holder, who deals with technical matters for a living. Those who know me personally, know that I would never jeopardize my reputation or my integrity, by posting data that would turn the Hobby/Industry on its ear, unless I was absolutely sure about the data I put out there. And for the record, I do not, and never have, used a one armed bandit tester to perform any motor oil testing. The test results I post are not my opinion, and they are not my theory. They are the actual facts that came out of the Physics and Chemistry involved in the real world testing I perform, at a representative operational temperature of 230*F. Of course I've always known my carefully generated data was completely accurate, but now my data has been validated by a total of three other independent Industry sources. They are as follows:

1. Well known and respected Engineer and Tech Author David Vizard, whose own test data, largely based on real world engine dyno testing, has concluded that more zinc can be damaging, more zinc does not provide today's best wear protection, and that using zinc as the primary anti-wear component, is outdated technology.

2. The GM Oil Report titled, "Oil Myths from GM Techlink", concluded that high levels of zinc are damaging and that more zinc does not provide more wear protection.

3. A motor oil research article written by Ed Hackett titled, "More than you ever wanted to know about Motor Oil", concluded that more zinc does not provide more wear protection, it only provides longer wear protection.

Those familiar with the test data I post, know that my testing came up with the exact same results stated by all three of those independent sources. This is an example where wear testing using an oil tester, engine dyno testing and proper motor oil research using only the facts, from four independent sources, all converged to agree and come to the same exact conclusion. Back-up validation proof, doesn't get any better than this, in the world we live in. In fact, in most cases in the Hotrod and Racing Industry, if you ask 10 people a question, you will get 10 different answers.

So, with all those sources in total agreement, that should provide more than adequate proof to anyone who questioned my test data, that the posts I make about motor oil testing, are absolutely correct. And that questioning one of them, questions them all. So hopefully, we can leave all the arguments behind, and as we go forward, engage in respectful motor oil discussions, which we all have an interest in.

Now, on with the oil data that is the subject of this posting. Synthetic 10W30 Amsoil Dominator Racing Oil, is the latest high zinc oil I've tested. Here is the Lab Test data that came back from Professional Lab, ALS Tribology in Sparks, Nevada:

Amsoil 10W30 Dominator Racing Oil synthetic (lab tested 2013)
Silicon = 3 ppm (anti-foaming agent in new oil, but in used oil, certain gasket materials and dirt can also add to this number)
Boron = 15 ppm (detergent/dispersant, anti-deposit buildup/anti-sludge)
Magnesium = 10 ppm (detergent/dispersant, anti-deposit buildup/anti-sludge)
Calcium = 1661 ppm (detergent/dispersant, anti-deposit buildup/anti-sludge)
Barium = 0 ppm (detergent/dispersant, anti-deposit buildup/anti-sludge)
Zinc = 1613 ppm (anti-wear)
Phos = 1394 ppm (anti-wear)
Moly = 0 ppm (anti-wear)
Potassium = 4 ppm (anti-freeze corrosion inhibitor)
Sodium = 0 ppm (anti-freeze corrosion inhibitor)
TBN = 6.5 (Total Base Number) This is an acid neutralizer to prevent corrosion. Most gasoline engine motor oils start with TBN around 8 or 9.
Viscosity (cSt at 100*C) = 11.6 (cSt range for SAE 30 is 9.3 to 12.4) And cSt (centistokes) in general terms, represents an oil’s thickness.

My testing showed that the onset of thermal breakdown for this oil was approximately 300*F, which tied for the highest value I've found in all the oils I've tested for the onset of thermal breakdown. The oils that had an onset of thermal breakdown value that high, have always been Amsoil products, in my testing.

My "Dynamic Wear Testing Under Load", which determines the specific wear protection limit of an oil by testing its "Load Carrying Capacity/Film Strength", found that this oil was capable of producing a very impressive 97,118 psi. This puts it in the OUTSTANDING WEAR PROTECTION category, and makes it one of the best high zinc oils I've tested. Below is how it ranked among the other high zinc (over 1100 ppm) oils I've tested.


Wear protection reference categories are:

*** Over 90,000 psi = OUTSTANDING protection

*** 75,000 to 90,000 psi = GOOD protection

*** 60,000 to 75,000 psi = MODEST protection

*** Below 60,000 psi = UNDESIREABLE

The higher the psi number, the better the wear protection.

1. 10W30 Lucas Racing Only synthetic = 106,505 psi
zinc = 2642 ppm
phos = 3489 ppm
ZDDP= 3000 ppm
NOTE: This oil is suitable for short term racing use only, and is not suitable for street use.

2. 10W30 Valvoline NSL (Not Street Legal) Conventional Racing Oil = 103,846 psi
zinc = 1669 ppm
phos = 1518 ppm
ZDDP = 1500 ppm
NOTE: Due to its very low TBN value, this oil is only suitable for short term racing use, and is not suitable for street use.

3. 10W30 Valvoline VR1 Conventional Racing Oil (silver bottle) = 103,505 psi
zinc = 1472 ppm
phos = 1544 ppm
ZDDP = 1500 ppm

4. 10W30 Valvoline VR1 Synthetic Racing Oil, API SL (black bottle) = 101,139 psi
zinc = 1180 ppm
phos = 1112 ppm
ZDDP = 1100 ppm

5. 10W30 Amsoil Dominator Racing Oil synthetic = 97,118 psi
zinc = 1613 ppm
phos = 1394 ppm
ZDDP = 1500 ppm

6. 30 wt Red Line Race Oil synthetic = 96,470 psi
zinc = 2207 ppm
phos = 2052 ppm
ZDDP = 2100 ppm
NOTE: This oil is suitable for short term racing use only, and is not suitable for street use.

7. 10W30 Amsoil Z-Rod Oil synthetic = 95,360 psi
zinc = 1431 ppm
phos = 1441 ppm
ZDDP = 1400 ppm

8. 10W30 Quaker State Defy, API SL semi-synthetic = 90,226 psi
zinc = 1221 ppm
phos = 955 ppm
ZDDP = 1000 ppm

9. 10W30 Joe Gibbs HR4 Hotrod Oil synthetic = 86,270 psi
zinc = 1247 ppm
phos = 1137 ppm
ZDDP = 1100 ppm

10. 15W40 RED LINE Diesel Oil synthetic, API CJ-4/CI-4 PLUS/CI-4/CF/CH-4/CF-4/SM/SL/SH/EO-O = 85,663 psi
zinc = 1615 ppm
phos = 1551 ppm
ZDDP = 1500 ppm

11. 5W30 Lucas API SM synthetic = 76,584 psi
zinc = 1134 ppm
phos = 666 ppm
ZDDP = 900 ppm

12. 5W50 Castrol Edge with Syntec API SN, synthetic, formerly Castrol Syntec, black bottle = 75,409 psi
zinc = 1252 ppm
phos = 1197 ppm
ZDDP = 1200 ppm

13. 5W30 Royal Purple XPR (Extreme Performance Racing) synthetic = 74,860 psi
zinc = 1421 ppm
phos = 1338 ppm
ZDDP = 1300 ppm

14. 5W40 MOBIL 1 TURBO DIESEL TRUCK synthetic, API CJ-4, CI-4 Plus, CI-4, CH-4 and ACEA E7 = 74,312 psi
zinc = 1211 ppm
phos = 1168 ppm
ZDDP = 1100 ppm

15. 15W40 CHEVRON DELO 400LE Diesel Oil, conventional, API CJ-4, CI-4 Plus, CH-4, CF-4,CF/SM, = 73,520 psi
zinc = 1519 ppm
phos = 1139 ppm
ZDDP = 1300 ppm

16. 15W40 MOBIL DELVAC 1300 SUPER Diesel Oil conventional, API CJ-4, CI-4 Plus, CI-4, CH-4/SM, SL = 73,300 psi
zinc = 1297 ppm
phos = 1944 ppm
ZDDP = 1600 ppm

17. 15W40 Farm Rated Heavy Duty Performance Diesel, CI-4, CH-4, CG-4, CF/SL, SJ (conventional) = 73,176 psi
zinc = 1325ppm
phos = 1234 ppm
ZDDP = 1200 ppm

18. 15W40 “NEW” SHELL ROTELLA T Diesel Oil conventional, API CJ-4, CI-4 Plus, CH-4, CF-4,CF/SM = 72,022 psi
zinc = 1454 ppm
phos = 1062 ppm
ZDDP = 1200 ppm
Yes it true, this new Rotella does in fact have more zinc than the old Rotella.

19. 0W30 Brad Penn, Penn Grade 1 (semi-synthetic) = 71,377 psi
zinc = 1621 ppm
phos = 1437 ppm
ZDDP = 1500 ppm

20. 15W40 “OLD” SHELL ROTELLA T Diesel Oil conventional, API CI-4 PLUS, CI-4, CH-4,CG-4,CF-4,CF,SL, SJ, SH = 71,214 psi
zinc = 1171 ppm
phos = 1186 ppm
ZDDP = 1100 ppm

21. 10W30 Brad Penn, Penn Grade 1 (semi-synthetic) = 71,206 psi
zinc = 1557 ppm
phos = 1651 ppm
ZDDP = 1600 ppm

22. 15W50 Mobil 1, API SN synthetic = 70,235 psi
zinc = 1133 ppm
phos = 1,168 ppm
ZDDP = 1100 ppm

23. 30wt Edelbrock Break-In Oil conventional = 69,160 psi
zinc = 1545 ppm
phos = 1465 ppm
ZDDP = 1500 ppm

24. 10W40 Edelbrock synthetic = 68,603 psi
zinc = 1193 ppm
phos = 1146 ppm
ZDDP = 1100 ppm

25. 15W40 LUCAS MAGNUM Diesel Oil, conventional, API CI-4,CH-4, CG-4, CF-4, CF/SL = 66,476 psi
zinc = 1441 ppm
phos = 1234 ppm
ZDDP = 1300 ppm

26. 10W30 Royal Purple HPS (High Performance Street) synthetic = 66,211 psi
zinc = 1774 ppm
phos = 1347 ppm
ZDDP = 1500 ppm

27. 10W40 Valvoline 4 Stroke Motorcycle Oil conventional, API SJ = 65,553 psi
zinc = 1154 ppm
phos = 1075 ppm
ZDDP = 1100 ppm

28. 5W30 Klotz Estorlin Racing Oil, API SL synthetic = 64,175 psi
zinc = 1765 ppm
phos = 2468 ppm
ZDDP = 2100 ppm

29. “ZDDPlus” added to Royal Purple 20W50, API SN, synthetic = 63,595 psi
zinc = 2436 ppm (up 1848 ppm)
phos = 2053 ppm (up 1356 ppm)
ZDDP = 2200 ppm
The amount of ZDDPlus added to the oil, was the exact amount the manufacturer called for on the bottle. And the resulting psi value here was 24% LOWER than this oil had BEFORE the ZDDPlus was added to it. Most major Oil Companies say to NEVER add anything to their oils, because adding anything will upset the carefully balanced additive package, and ruin the oil’s chemical composition. And that is precisely what we see here. Adding ZDDPlus SIGNIFICANTLY REDUCED this oil’s wear prevention capability. Just the opposite of what was promised. Buyer beware.

30. Royal Purple 10W30 Break-In Oil conventional = 62,931 psi
zinc = 1170 ppm
phos = 1039 ppm
ZDDP = 1100 ppm

31. 10W30 Lucas Hot Rod & Classic Hi-Performance Oil, conventional = 62,538 psi
zinc = 2116 ppm
phos = 1855 ppm
ZDDP = 1900 ppm

32. 10W30 Comp Cams Muscle Car & Street Rod Oil, synthetic blend = 60,413 psi
zinc = 1673 ppm
phos = 1114 ppm
ZDDP = 1300 ppm

33. 10W40 Torco TR-1 Racing Oil with MPZ conventional = 59,905 psi
zinc = 1456 ppm
phos = 1150 ppm
ZDDP = 1300 ppm

34. “ZDDPlus” added to O’Reilly (house brand) 5W30, API SN, conventional = 56,728 psi
zinc = 2711 ppm (up 1848 ppm)
phos = 2172 ppm (up 1356 ppm)
ZDDP = 2400 ppm
The amount of ZDDPlus added to the oil, was the exact amount the manufacturer called for on the bottle. And the resulting psi value here was 38% LOWER than this oil had BEFORE the ZDDPlus was added to it. Adding ZDDPlus SIGNIFICANTLY REDUCED this oil’s wear prevention capability. Just the opposite of what was promised. Buyer beware.

35. 10W40 Summit Racing Premium Racing Oil, API SL conventional = 59,483 psi
zinc = 1764 ppm
phos = 1974 ppm
Claimed ZDDP level on the bottle = 1800 ppm
NOTE: Summit discontinued this line of oil, as of spring of 2013.

36. “ZDDPlus” added to Motorcraft 5W30, API SN, synthetic = 56,243 psi
zinc = 2955 ppm (up 1848 ppm)
phos = 2114 ppm (up 1356 ppm)
ZDDP = 2500 ppm
The amount of ZDDPlus added to the oil, was the exact amount the manufacturer called for on the bottle. And the resulting psi value here was 12% LOWER than this oil had BEFORE the ZDDPlus was added to it. Adding ZDDPlus SIGNIFICANTLY REDUCED this oil’s wear prevention capability. Just the opposite of what was promised. Buyer beware.

37. “Edelbrock Zinc Additive” added to Royal Purple 5W30, API SN, synthetic = 54,044 psi
zinc = 1515 ppm (up 573 ppm)
phos = 1334 ppm (up 517 ppm)
ZDDP = 1400 ppm
The amount of Edelbrock Zinc Additive added to the oil, was the exact amount the manufacturer called for on the bottle. And the resulting psi value here was a whopping 36% LOWER than this oil had BEFORE the Edelbrock Zinc Additive was added to it. Adding Edelbrock Zinc Additive SIGNIFICANTLY REDUCED this oil’s wear prevention capability. Just the opposite of what was promised. Buyer beware.

38. 10W30 Comp Cams Break-In Oil conventional = 51,749 psi
zinc = 3004 ppm
phos = 2613 ppm
ZDDP = 2800 ppm

39. “Edelbrock Zinc Additive” added to Lucas 5W30, API SN, conventional = 51,545 psi
zinc = 1565 ppm (up 573 ppm)
phos = 1277 ppm (up 517 ppm)
ZDDP = 1400 ppm
The amount of Edelbrock Zinc Additive added to the oil, was the exact amount the manufacturer called for on the bottle. And the resulting psi value here was a “breath taking” 44% LOWER than this oil had BEFORE the Edelbrock Zinc Additive was added to it. Adding Edelbrock Zinc Additive SIGNIFICANTLY REDUCED this oil’s wear prevention capability. Just the opposite of what was promised. Buyer beware.

40. “Edelbrock Zinc Additive” added to Motorcraft 5W30, API SN, synthetic = 50,202 psi
zinc = 1680 ppm (up 573 ppm)
phos = 1275 ppm (up 517 ppm)
ZDDP = 1400 ppm
The amount of Edelbrock Zinc Additive added to the oil, was the exact amount the manufacturer called for on the bottle. And the resulting psi value here was 22% LOWER than this oil had BEFORE the Edelbrock Zinc Additive was added to it. Adding Edelbrock Zinc Additive SIGNIFICANTLY REDUCED this oil’s wear prevention capability. Just the opposite of what was promised. Buyer beware.

41. 30wt Lucas Break-In Oil conventional = 49,455 psi
zinc = 4483 ppm
phos = 3660 ppm
ZDDP = 4000 ppm

What's far more important than this 41 high zinc oil ranking list, is the entire 97 oil ranking that you can see, along with additional motor oil tech info at:

http://540ratblog.wordpress.com/

And here are some trends that you will see in that entire 97 oil ranking list:

• Synthetic oils rank between number 1 and number 96.

• Conventional oils rank between number 6 and number 97.

• Since the ranking of synthetic oils and conventional oils completely overlap, there is no clear distinction between their wear protection capabilities.

• High zinc oils rank between number 3 and number 97, which very clearly shows that simply having a high level of zinc is no guarantee of superior wear protection.

• Low zinc oils rank between number 1 and number 74.

• Since the low zinc oils and the high zinc oils completely overlap, you can see that zinc does not play the primary role in determining an oil’s wear protection capability. An oil’s wear protection capability is determined by its base oil and its additive package “as a whole”, with the primary emphasis on the additive package, which contains the extreme pressure components. And modern alternate extreme pressure components are equal to, or better than zinc.

• Diesel oils rank between number 43 and number 78. The poor performance of these Diesel oils makes it very clear that they are a poor choice for High Performance gas engines.

• Break-In oils rank between number 73 and number 97. If you are looking for wear protection during break-in, you will be disappointed with these oils. Because they are NOT formulated to prevent wear, they are formulated to allow the parts to quickly “wear in”, which is totally unnecessary. You cannot stop parts from wearing-in on their own, no matter what oil you run. And we’ve seen that for many years with factory filled synthetic Mobil 1 in countless thousands of brand new factory vehicles, that always break-in just fine. That makes break-in oils little more than snake oil. Buyer beware.

• 20 wt oils rank between number 12 and 90.

• 30 wt oils rank between number 1 and 97.

• 40 wt oils rank between number 43 and 89.

• 50 wt oils rank between number 7 and 82.

So, as you can see, oil viscosity plays no particular role in an oil’s wear protection capability. As mentioned above, an oil’s wear protection capability is determined by its base oil and its additive package “as a whole”, with the primary emphasis on the additive package, which contains the extreme pressure components.

540 RAT

Member SAE (Society of Automotive Engineers)

pws69

Thanks again, Sir! Your efforts and thorough, clear results are greatly appreciated!

C66 Racing

Not to re-open the validity of 540 RAT's testing, but as the title of this thread is AMSOIL I'd like to remind anyone reading it, happy to get AMSOIL for you at wholesale (see below).

I do use the Dominator 10w30 in my 02 Z06 at the track and based on ring and bearing wear in my engine tear downs (which we do about every other year after about 10 race weekends or so), the oil does perform well.
AMSOIL Dominator Synthetic 10w30 Racing Motor Oil (Product Code RD30QT)
(zinc – 1575 ppm, phosphorus 1474 ppm)

That said, I think the very similar Z-ROD is a better choice for a street driven or dual use car:
AMSOIL Z-ROD 10w30 Synthetic Motor Oil (Product Code ZRTQT)
(zinc – 1440 ppm, phosphorus 1320 ppm)

More than happy to get AMSOIL products for forum members at dealer wholesale pricing, about 25% below retail, via the AMSOIL Preferred Customer Program. Drop me a PM if interested.

Griff2002

Thanks for sharing the data. Do you have any data on oxidation testing? One of the things that will likely be added to specifications with GF-6 is how good the viscosity retention will be as the oil ages. G-6 is under development and will likely be implemented around 2016 or so.

rjoyal

What about horsepower differences?

Wear protection sounds like something I'd worry about in my Subaru wagon.

What I want to know is: which one of these will take the least amount of horsepower to pump while still keeping my motor together?

NEO1

Thanks for sharing. I'm not trying to argue here, but I don't think these results have any correlation to actual wear inside an actual engine. What type of test did you use to get these values?

Oils have to go through extensive engine testing, something like the Sequence IIIG etc.

Try posting this on www.bobistheoilguy.com

NEO1

Amsoil likes to use the gimmicky 4-ball wear test, which is really a joke when you talk to people that actualy work for oil companies and additive suppliers.

Also, I see some people continuously post the HT/HS specs and compare oils. That's just one componenta and doesn't tell you much on it's own. Anyone can make a shear stable oil. It's not hard to do. Use higher quality base oils and little to no viscosity modifiers or some of the new advanced polymers that are out there such as the ones found in Toyota's 0w20 and you have a shear stable oil.

NEO1

Engine Oil Performance Testing

"I have seen a number of lubricant manufacturers refer to the 4-ball wear scar test as an indicator of how well the oil will protect an engine. Other larger companies tend to brush off the results of this test indicating that it isn't representative of actual engine conditions adding that because it is cheap to run, the results aren't worth much. What are your thoughts on this?"

The 4-ball test (ASTM D4172) is often used as a screening test for many different lubricant types that contain antiwear additives or similar base oil properties. Other tribo-mechanical bench tests are often used as well, including the Timken Test (ASTM D2782) and the Pin and V-Block (ASTM D2670). Because engines have different contact geometry, loads, metallurgy and speeds, numerous bench tests and test protocols are needed. It is not uncommon for several oils to be tested using two such methods and to find that the performance rankings between the oils to reverse (no correlation). This is why, among other reasons, Passenger Car Motor Oils and Heavy Duty Oils (diesel crankcase) are tested in actual engines using controlled methods such as ASTM D5533 Sequence IIIE and D5302 Sequence VE.

Jim Fitch, Noria Corporation

NEO1

I like Amsoil a lot. They make some outstanding products, no question about it. I find it so hypocritical though for them to make a video exposing the one arm bandit test when they themselves use the 4-ball wear test.



Mobil 1 R&D center


At the 2:45 mark, they show you some of the tools used to measure and identify wear.

At 4:45 they show you the actual "engine" testing where they put Mobil 1 through 25,000 mile drain intervals.

johnt365

I admit I am scared!!! and confused

I have a small block with a comp cam xe268h. Right now I am using Amsoil Z-rod #23 on the list. At $9.80 a qt that's $50ish with shipping. I hate mail order oil. I hate expensive oil even more. But, I really don't want to take that cam out flat...

I would love to just walk into a local store and buy a jug of #4 on the list, Mobile 1 and be done for $30.

***You write an excellent article*** And it is evident that you are a professional. You hit the nail smooth on the head. Myths feed on ignorance, fear and doubt of which I want to be free of!

It's like vitamin supplements ... Some folks say you don't need to take any supplements, just eat a balanced, healthy diet. Other folks say that not only are our eating habits preventing poor nutrition but the quality of our mass produced food supply today provides less nutrition to begin with.

You have farmers growing nutritionally sterile produce, meat producers raising animals in conditions that would make a small child cry to see, supplement manufacturers who make a TON of money on a product that may or may not have a placebo effect.

Problem is you don't know who's right until you die.

Can anybody tell if someone walking down the street is hopped up on an extra 1000mg of vitamin C? I'm sure lots of people are choking down a few 1kmg of vitamin C just for good measure.

But, deprived of vitamin C and die of scurvy.

So there you go. I'm afraid car will get cam scurvy if I quit giving it vitamin Zinc supplements.

Thank you for all your work and data.

63mako

Bingo! This is a 30 second film strength test on new motor oil. It is not "Dynamic Wear Testing Under Load" and the pressure that breaks the film strength 97,118 psi is no where near the 200,000 + PSI seen at the lobe/ lifter interface in a stock flat tappet engine so this test in no way tests extreme pressure additives or their effectiveness long term. This testing shows that the Amsoil Dominator oil tested has a high level of film strength @ 230 degrees and will withstand high temperatures as a true synthetic Group IV basestock should. ZDDP does not attack the surface of engine internals at levels below 1600 PPM. There is some "peer review" on Speedtalk. Any testing needs to survive "peer review.

budco

RAT540 thank you for posting the data.

I am a fan of Amsoil and have been using it in my Harleys for 10 years and my cars for about 6 years. I use it in my Harley's because they are air cooled and I live in the south so the engine's are under extreme conditions. I believe the synthetics will hold up better in these conditions. I use it in my cars because I like the longer oil change intervals. I have been one of those all my life that changed his oil at 3000/3 months and most of the time the oil didn't have 1500 miles. The oils are much better now days and I'm tired of throwing money away.

To me this is one of those arguments that there will be no clear winner. In my opinion there are many reasons people like a specific oil. It may be they have the best commercials or their great grandfather told them to use it or whatever.......

I have been a master mechanic for a national fleet for about 25 years. My trucks run about a million miles a year on in town routes and we have used a few different oils over the years. We have gas engines as well as diesels and I have replaced a "few" engines. I have to say I don't remember changing any engines because of oil failure, or a damaged part that oil failure would cause. We have always used a major brand of oil and never synthetic and it has worked.

Just my 2 cents.....

63mako

I am a big fan of Amsoil also!

slow_pokeC5

I've been trying to decide between Valvoline VR1 and Amsoil Dominator 10w30 for my 02 Z06 (142,500 miles) and this was the data I was really looking for!

I am actually curious though if you can get your hands on some Synergyn Oil to see what their 5w30 or 15w50 did in your tests. I use to use that stuff in my racecar and supposedly it's the greatest thing on earth in the oval racing community... I would run that stuff 5 or 6 races before changing it and it would still come out golden colored.

Iron_dog

Thanks for the data, I'm interested to see how the Amsoil 10w40 Premium Protection stands... Any data on it? Thanks

Tact

https://www.corvetteforum.com/forums...test-data.html