Quick backstory: I love my 2013 C-Max and bought it used about 2 and a half years ago.
My average mpg on a tank of gas is usually between 47 and 48. I'm very happy with that, and that's using 87 octane gas from Kroger with ethanol (fuel points) = big savings).
For my birthday, I got some cash just to buy one tank of 100% gas, just for fun, to see what it does to the mileage.
This car always gets 87 octane with 10% ethanol.
My question is: if I'm going to buy just one full tank of 100% gas, should I get 87 octane 100% gas or 93 octane 100% gas if both are available.
I just want to make sure I'd be ok to run one tank of 93 octane no ethanol, and then go right back to the usual 87 with ethanol.
Thanks for any help!