If you thought 0W-20 was thin, meet 0W-8 and 0W-12!
By Lake Speed Jr.
Over 10 years ago, SAE revised the viscosity grade system and added three new lower viscosity grades – 0W-16, 0W-12 and 0W-8. This was done at the request of the OEMs as they looked to squeeze a little more fuel economy out their engines for the EPA Corporate Average Fuel Economy (CAFE) tests. At that time, the American Petroleum Institute (API) decided to only license the new 0W-16 viscosity grade, and those products would have different labeling than the other traditional viscosity grade products. Instead of the familiar ILSAC (International Lubricant Standards Committee) “Starburst” emblem on the label, these new 0W-16 oils would feature a new “Shield” design.
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These new 0W-16 oils are part of the ILSAC GF-6 standard with correlates to the current API SP motor oil specification. GF-6 has two subcategories – GF-6A for the traditional 10W-30, 5W-30, 0W-30, 5W-20, and 0W-20 viscosity grades and GF-6B for the new 0W-16 viscosity grade.
The GF-6A oils claim the “backwards compatibility” that goes along with latest API SP motor oil specification. However, the GF-6B oils do not claim to be backwards compatible. To be honest, what engines called for 0W-16 before then anyway? Still, this new category of oils has new viscosity grades and new labeling to prevent consumer confusion and possible misapplication.
With a few years under the belt, API recently adopted the other two new viscosity grades into the API SP family. Welcome 0W-12 and 0W-8 to your local auto parts store shelf!
So, let’s get to the question I’m sure you are asking, is that stuff too thin? Let me share my personal experiences with both 0W-12 and 0W-8 motor oils.
0W-12
About eight years ago, I began working on a development project with Oak Ridge National Lab and General Motors. The goal of the project was to formulate a 0W-12 motor oil using novel (fancy word for new or atypical) chemistry and test it in an engine designed for a 5W-30.
It just so happened that the 0W-12 viscosity grade was really close to the 0W-16 viscosity oil we were using in the engines at Joe Gibbs Racing. However, the additive package in that JGR 0W-16 was not appropriate for street use, thus not applicable to this project. At least not as it was, so I adjusted the levels of ZDDP, Molybdenum, detergents, and dispersants to come up with street worthy cousin of the JGR race oil.
That was way easier said than done.
With lots of help from the folks at Oak Ridge National Lab (ORNL) we conducted dozens of wear tests to select a couple of additive combinations to dyno test in a real engine. Just to be safe, we blended the oils as 0W-30 grade test candidates, and then we shipped them off to Shaver Specialties Racing Engines to test them in our venerable, flat tappet small block Chevy.
Both of the new oils worked well, so now it was time to make them as 0W-12 oils and test them in a new GM LT1 direct injection engine. Fortunately, Ben Strader at EFI University had an LT1 on his dyno for doing some camshaft testing for Comp Cams on this new-at-the-time engine platform, so we blended up some 0W-12 candidate oils to test against a 0W-20 Dexos 1 blend.
The back-to-back to back 3-hour tests showed a fuel economy improvement using the 0W-12 over the 0W-20, and the used oil analysis results showed the wear protection was good as well.
Now it was time to let GM test both oils in their direct injection LT1 engine for 100 hours at 150C oil temperature.
The baseline oil was a GM Dexos 1 approved 5W-30 synthetic, and it was run both before and after the two 0W-12 candidate oils to ensure a proper baseline for comparison. To everyone’s surprise, the used oil analysis results revealed both 0W-12 oils outperformed the baseline Dexos 1, 5W-30 synthetic in terms of wear protection by a wide margin.
To be fair, this was not an ordinary motor oil. However, it did show that the viscosity grade alone was not a problem.
Now, fast forward to last summer. My youngest daughter purchased a brand-new Toyota Corolla. I went with her to pick it up, and I noticed the paperwork said the car was built in Japan. I know there are lots of Toyota plants in the USA, so that struck me as odd. A few weeks later, I asked my daughter how many miles where on her car, and she said just over 500. I told her to bring it over to the house that weekend so I could do an oil change on it. There was no way I was letting her go 10,000 miles on the first oil change.
To be prepared, I asked her to check the oil fill cap to see what viscosity they specified. I figured it would be 0W-20 or maybe even 0W-16. To my shock, she said 0W-8.
At that time, API had not adopted the 0W-8 viscosity grade, so there was no way 0W-8 was going back into the engine (even if I wanted to). Instead, I purchased some of the Toyota 0W-16 synthetic and used that for the oil change.
Being that I am also a used oil analyst, I took samples of that factory fill 0W-8 and the Toyota Genuine 0W-16 for analysis. To my surprise for the second time, the Toyota 0W-8 chemical analysis revealed some similarities to the 0W-12 I formulated that performed so well against the 5W-30 in GM’s testing. All of this showed that certain chemistries enable lower viscosity oils to perform better than we would expect.
Now, I’m not recommending that you run out and put 0W-8 in everything you own (remember they are not backwards compatible), but you should not be afraid of them either.
Read this article with all images in the digital issue of Engine Professional magazine https://engineprofessional.com/2024EPQ2/#p=18