93-octane necessary?

[TwizzleStix]

This topic is a dead horse. Has been forever. So dead it's just a pile of smelly goo. Just run whatever crap fuel you want, but anyone who has even a little a clue about how an ICE functions knows that peak performance in ANY forced induction engine is achieved with the highest octane (which is the resistance to spontaneous ignition) fuels. Personally, my Ecoboost engine(s) prefer a mix of ~50% 93 octane gasoline and ~50% pure corn whiskey. Right now it has ~61% corn whiskey in it. The ECU adds ~10% fuel trim, so it still runs at stoic (for my fuel) at lower loads and at my set AFR at higher loads because the Ecoboost(all) always run in closed loop. Their "open loop" just means it's not running at the set stoic AFR. When the tune is adjusted to take advantage of the additional resistance to spontaneous ignition (you know, octane) provided by the corn whiskey, the power output is crazy high. Pure corn whiskey is an awesome fuel additive...

People who run or recommend to run the cheapest fuel available (87 ?) in any forced induction engine are literally ignorant or maybe just plain stupid(?). YMMV

 

[Retired in TN]

Is Premium Gas Worth It? We Test High Octane on 4 Popular Vehicles

We tested higher octane fuel than manufacturers require on the Honda CR-V, BMW M5, Ford F-150, and Dodge Charger to see if it impacted acceleration or MPG.

www.caranddriver.com

I found this Car and Driver article an educational read. The 3.5L benefits from higher octane, including a 5% mpg boost. Not true for every sports car engine though.