I was looking at some car auctions on Trademe today, and came across an answer to a question about whether the car would run on 91 petrol. The seller (who is a car dealer who sells tens of cars a week) said that "It will run on 91, but I wouldnt run ANY car on 91. It is a false economy to put crap petrol in a car. You are better off with 96. The car will like it and it will go further.".
Does anybody know if this is true? My car is a Japanese make (Honda Civic) and I have always used 91, as this is what the car was designed for. Is there any reason I would be better off putting 96 in it?
I understand the reasons why you wouldn't want to put lower grade petrol than recommended in, but I have no idea what the positive effects are, if any, or putting higher than recommend grade petrol in.