Gas mileage by brand
Hypothesis: Some fuel gets you better mileage than others. Duh!
What is the best fuel to use assuming all prices equal? I'm asking because my wifes friend claims that she used Esso 87 forever (Esso points), and one day she used PetroCan 87 and got nearly 20% better mileage out of the tank.
First question: do you usually drive in the city and that day you were out on the highway? No, she just drives to/from work same route every day and groceries on weekend.
Second question: are you sure? Yes, same results on a second tank.
I find the 20% claim really tough to swallow.
Implication of PetroCan 87 getting 20% better mileage than Esso 87: Esso goes out of business while everyone lines up at PetroCan as long as the price of PetroCan 87 is less than 1.2x the price of Esso 87.
Anyone validated improved mileage across brand/premium?
I have a thing for Shell 91 in my motorcycle because the bike just works better without ethanol, and the cost differential per km is about 1c, and that's my only bias.