I've done many traveling miles and monitored where I bought gas and the mileage I got. I found a few things including where you buy makes a difference. Shell oil is my choice but there are others. I also found keeping it at 65 is far better than faster like 70mph. And my jeep is most efficient at ~2200 rpm's dispute 5th or 6th gear differences.
Why a tank of 93 octane? It is harder to burn. It requires a high compression environment that a jeep is not designed to provide. Aren't you just sending a lot of un-ignited fuel out your tailpipe?
The higher the octane the hotter it burns. You don't need higher compression to burn 93. With a hotter burn and a bottle of injector cleaner it helps decarbonize your 4.0L.
Why a tank of 93 octane? It is harder to burn. It requires a high compression environment that a jeep is not designed to provide. Aren't you just sending a lot of un-ignited fuel out your tailpipe?
Not true. Higher octane can be compressed more at high temperatures before detonating. Or It can be diluted with oxygen more than lower octane at the same compression without knock. it is pouring more money into gas that these engines will not benefit from. Unless you increase compression ratio, stroke it or add a blower.
"The fuel property the octane ratings measure is the ability of the unburnt end gases to spontaneously ignite under the specific test conditions. Within the chemical structure of the fuel is the ability to withstand pre-flame conditions without decomposing into species that will auto ignite before the flame-front arrives... Antiknock additives work by interfering at different points in the pre-flame reactions, with the oxygenates retarding undesirable low temperature reactions..." (Hamilton 6.4).