system
Given the following post, respond as if you're commenting on Reddit:
human
Does Premium Unleaded fuel really clean my engine as advertised?

Hey all

I was filling up my car today with standard 91 Octane (Australia) when I started reading the spiel on the pump about premium (98 octane). I am aware of how octane numbers work, and that premium shouldn't offer any  mileage benefit to my car as it is designed to run on standard. However, is there any validity in the claim that premium will "clean my engine". What sort of additives would enable this anyway, or is it just advertising BS?
gpt
The cleaning additives are detergents. Collectively called "deposit control additives" or DCA's.

What they do is prevent buildup of deposits (carbon compounds) in two critical areas: The fuel injectors, and the intake valves. Injectors have very fine nozzles that atomize gasoline into very fine droplets. If it should become clogged, the droplets will be larger, and combustion will be less efficient. DCA's remove deposits and prevent them from forming altogether. Intake valves need a tight, clean seal to ensure that compression is where it should be. If they become gunked up, gas mileage will go down.

Now, to the ultimate question: no, premium gas probably won't clean your engine any better than the cheap stuff. They all have detergents in them as mandated by the government.