answer:It does. Higher octane ratings are more resistant to “knocking”. Engines with higher compression and/or that have forced induction (turbos or superchargers) are more prone to pinging and thus generally require higher octane to avoid detonating the fuel-air mixture at the wrong time. Modern cars can adapt quickly to stop knocking by altering the mixture and/or ignotion timing, though doing so reduces fuel efficiency and horsepower. My car with it’s carburetor and distributor doesn’t have that luxury, so instead of pinging leading to a quick recalibration, it leads to engine damage. My 4A-LC is robust enough that the damage is minor so long as I don’t make a habit of it, but an old RX-7 will blow the apex seals and require an engine rebuild after just a couple of “pings”... which will take less than 0.03 seconds at normal cruising speeds. The RX-7 is a notably fragile example as most engines can tolerate some detonation, but it’s really not something you want to have happen if you can avoid it. My first Corolla would not run right on 87 unless I reach under the hood and retard the ignition timing so far that it won’t make enough HP to get to highway speeds or to climb a hill at any speed. With 93-octane, I could keep the timing at factory specs and drive normally. My current Corolla can run on 87, though it won’t get over 55 MPH, can barely make hills, and gets ~23 MPG. When I use 92-octane (WA doesn’t have 93), I have no difficulty doing… let’s call it 65, and gets ~27 MPG. My wife’s old Saturn got 26 MPG and was a little sluggish on 87-octane; with 93 it went up to 28.5 MPG (enough of am improvement to actually lower the $/mile despite the added fuel cost) and was slightly peppier.