Are all “fully synthetic” oils the same?
When it comes to engine oils, the word “synthetic” can be confusing. Many people assume a synthetic oil is entirely man-made — but the reality is that some oils sold as “fully synthetic” actually contain a blend of synthetic and mineral base oils. That practice has long been debated, with some experts arguing it’s misleading to the rider buying the bottle.
A label that went to court
The most famous example dates back to 1999, when one major oil company sued another over whether its “synthetic” motor oil was truly synthetic — because it was built on a hydro-isomerised mineral oil rather than a purely synthetic base. The defending company argued that this was simply common industry practice. The case settled out of court, but it left the category with a lasting grey area: “fully synthetic” doesn’t always mean what a rider thinks it means.
Why it still matters today
Many manufacturers continue to blend synthetic and mineral base oils in products marked “fully synthetic.” These blends can perform well and protect your engine — but they may not meet the strict definition a rider assumes when they pay a premium for “synthetic.” If you want a genuinely 100% synthetic oil, the label alone won’t always confirm it.
How to actually read the label
Two checks cut through most of the ambiguity:
Spotting a true synthetic
- Look for explicit wording: “PAO synthetic,” “fully synthetic PAO,” or “100% synthetic PAO” — not just “synthetic technology.”
- Check the viscosity index (VI). PAO-based synthetics resist thinning at temperature extremes, so they carry a higher VI than mineral oils.
- A VI above 140 is a strong signal the oil is built on a genuine synthetic base rather than a mineral blend.
- If a brand won’t tell you the base oil at all, that silence is itself an answer.
None of this makes blends “bad” — a good synthetic-mineral blend can offer excellent protection and often costs less. The point isn’t that one is always right; it’s that you should be able to know which one you’re buying. That’s a decision a rider deserves to make on facts, not on a word printed in a big font.
Where TWIIN stands
This is exactly why we declare our formulation openly on every pouch. Our fully synthetic is PAO-based with a viscosity index above 140 — and we say so, plainly, rather than asking you to trust the word “synthetic” on its own. If you’ve read this far, you already know more than most oil labels want you to.
Nothing to hide.
See the openly declared range on your marketplace of choice.