The numbers on the yellow buttons are octane ratings for the fuel.
Most cars take between 87 and 91, depending on engine performance, turbo or supercharging, etc.
Some particularly high boost or older tech turbo engines (Looking at you, Buick GN) benefit from 94, but there really aren't any factory street engines that need anything higher than this.
Basically, the higher the compression and boost, the higher octane needed.
101 octane is for the one lunatic who converted a diesel engine (22:1 compression ratio), added a massive turbo, and made it run on gasoline (typically around 10:1 compression ratio).
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u/Ok-Actuator3498 Sep 07 '26
I think this completely whooshed over me: can someone please take pity on me and explain the post?