ummm … i am hoping … if you land at petro-station running on fumes … and they have no premium left … you will pump regular into your tank. just at the next fill-up … make sure it’s premium. unless you’re like me … been putting regular in from day one … 420k miles later finally replaced the honda … to this day, still continue that practice. and, no … there was never any engine ‘knock’.
Premium or regular simply doesn’t matter to a post 1990-ish car.
Prior to then you *could *cause damage if you drove a premium-only car on regular AND also beat it like a red-headed step child. Starting in about 1990 the cars are smart enough to not let you beat them any harder than they can safely withstand indefinitely without increased wear or damage.
Quit obsessing about something that absolutely positively does not matter.
The worst experience you *might *have is slightly reduced gas mileage and slightly reduced peak power. For 90% sure you’ll save money by running regular. The only way you wouldn’t is if you had a way to buy premium for only a couple pennies a gallon more than regular. I’m looking at 45 cents a gallon extra around here and it’s pure wasted money to pay that.