Key takeaways:

- This was a side by side comparison test of Valvoline products. They weren't out to throw stones at either oil they make and sell.
- Both engines survived just fine to 500K miles. Very few people drive their car that many miles.
- Carbon deposits were significantly higher with the conventional oil.
- The carbon deposits on the conventional oil turbo were concerning, imo.
- Sludge was much higher with conventional, virtually non-existent with synthetic.
- Oil changes matter. Even though the synthetic clearly outperformed the conventional, as stated above both engines made it to 500K miles just fine. That well exceeds expectations for most people.
- I, personally, would only use synthetic in a turbo engine. The heat of that turbo burns up conventional oil causing those carbon deposits that were shown on the turbo wheel towards the end of the video. The synthetic turbo wheel was virtually clean. They did have to replace the turbo in the conventional oil engine, but it was left unsaid as to what caused the waste gate failure. What was clear, though, is the 500K mile synthetic oil turbo wheel looked in much better shape than the 300K mile conventional turbo wheel.


https://www.youtube.com/watch?v=l4D8C6WR3pE