This is assuming there’s no active knock sensing and timing control, which is unlikely on anything made in the last 15-20 years, especially if it requires premium. The manufacturers learned that people are often stupid, and mistakes happen. So a tank of low grade here or there can be accounted for. But if you use it constantly while beating on the engine, yeah, damage will add up over time if you exit the bounds of what the computer can adjust for.
Nope. Eventually it will probably accelerate to where you have to add nearly daily, and at that point you’ll know it’s time to throw in the towel.
Just read the manual and find the octane section, and put in the minimum that is stated there. Many cars “recommend” premium/91+ for full performance, but that doesn’t mean they need it, they just benefit.
Some cars literally demand 91+ though. Not using it won’t be immediately fatal, but you may hear it pinging away during acceleration on a hot summer day. If it’s newer and has active knock sensing/retard it will just be working overtime constantly, which isn’t ideal for the long term engine life.
Unless you have a super dense city layout, trains are bad at final mile delivery. So in order for people to get from their homes to the train (in the majority of US cities), you need a sensible way for them to travel in instances of bad weather or high/low temperatures. I’m all for more bike paths for regular and electric bikes and scooters and such, but not everyone can use those. So what else is there besides a car?
Also, I’m sure the article touches on these things, but I’m also not going to make an account to be able to read it, lol.