Piston Slap: Synthetic Oil's Historic Race to The Bottom?

TTAC Commentator RS writes:

How much Synthetic Oil is actually in Semi-Synthetic Oil? Why is that info so hard to find?

Sajeev answers:

Why? Relevance and (by definition) minutia’s lack of importance.

I personally think manufacturers should publish vehicle’s torque curves, drag coefficients, frontal area dimensions and all gear ratios on their websites. Damn near everyone else couldn’t give two shits about that.

But I digress…there are five groups/classifications of oils in the USA, and the three highest are classified as synthetic.

Group III is the sticking point for many folks: if this thread has any credibility, here’s why Mobil 1 oil went “down” from a pure synthetic oil. And nobody wants to talk about it!

Mikey100’s quote is a brilliant assessment:

“In the late 1990s, Castrol started selling an oil made from Group III base oil and called it SynTec Full Synthetic. Mobil sued Castrol, asserting that this oil was not synthetic, but simply a highly refined petroleum oil, and therefore it was false advertising to call it synthetic. In 1999, Mobil lost their lawsuit. It was decided that the word “synthetic” was a marketing term and referred to properties, not to production methods or ingredients. Castrol continues to make SynTec out of Group III base oils, that is highly purified oil with most all of the cockroach bits removed.

Shortly after Mobil lost their lawsuit, most oil companies started reformulating their synthetic oils to use Group III base stocks instead of PAOs or diester stocks as their primary component. Most of the “synthetic oil” you can buy today is actually mostly made of this highly-distilled and purified dino-juice called Group III oil. Group III base oils cost about half as much as the synthetics. By using a blend of mostly Group III oils and a smaller amount of “true” synthetics, the oil companies can produce a product that has nearly the same properties as the “true” synthetics, and nearly the same cost as the Group III oil. In fact, Mobil-1 is now primarily made from Group III unconventional base oils, exactly the stuff Mobil was claiming was not really synthetic. The much more expensive traditional synthetics are now available in their pure forms only in more expensive and harder to obtain oils.”

See how the world (the USA, in this case) works? When someone finds the easy way out, it’s a race to the bottom.

But we shouldn’t care: Group III full synthetic oils are pretty much fantastic for the majority of engines on the road. Most cars don’t use or require it, as synthetic blends are now all the rage from the factory. And synthetic blends are not the same as a Group III full synthetic oil.

Unless you own an M-series BMW or a Ferrari with a mandatory oil brand/weight as per owner’s manual, odds are Group III oil is the best you’ll ever need. Or want. Best and Brightest?

[Image: Shutterstock user Africa Studio]

Send your queries to sajeev@thetruthaboutcars.com. Spare no details and ask for a speedy resolution if you’re in a hurry…but be realistic, and use your make/model specific forums instead of TTAC for more timely advice.