Octane is a measure of a fuels resistence to combust. IE a 93 octane will be harder to ignite than an 87. The higher the compression, the more combustion resistence you get.

Thats the only difference, labling higher octane fuel as "premium" is misleading, it isn't any better or worse than the other. All gas is required to have the minimum amount of cleaners in it etc.

What it really comes down to is, run what the manual calls for. If spending a few extra cents on 91 or 93 really makes that much of a difference in your budget you have no business buying a high end car.

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2016 Corvette Stingray 2LT
1969 280SE
2023 Ram 1500
2007 Tiara 3200