Comments by "ToughAncientSpark" (@freetolook3727) on "Premium gas vs. regular: What's really better for your car? (CBC Marketplace)" video.

Premium and regular have nothing to do with clean. It has to do with octane. It's not so much an issue with modern cars as computers and electronics compensate for predetination or engine knock. In older vehicles, if you went up a hill and you had engine knock, one of the ways to compensate was to use premium fuel. I remember some guys mixing 100 octane airplane fuel with regular gas to boost engine performance. Long story short, if your car engine does not knock under load, use regular. If it does, switch to premium.
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