92 Octaine Gas?

OK, I searched for info on this and came up dry. So I will ask it here.

Will running higher octane fuel on a post-RENIX 4.0L offer any benefit? Does the engine adjust the ignition timing to the higher octane benefits somehow without the knock sensor?

Is there any benefit to running the higher octane gas?

In California, and many places now, the gas is 10% ethanol regardless of octane, so the power and fuel economy is already suffering. Does running higher octane recover any of that loss?

Not unless the engine is designed to take advantage of the higher octane.

Higher octane= less volatility. good for high compression and power adders, but a waste of $$ on a big stupid tractor motor like the 4.0. There is less energy in a gallon of 92 vs a gallon of 87

Don't waste your money. The higher the octane number, the more compression the fuel can withstand before detonating. You aren't increasing your compression so the boost in octane won't do anything for you.

Not going to help one bit. Octane is simply anti-knock index. The 4.0 engine runs perfectly fine on regular gasoline.

Premium fuel does not necessarily pack more energy content than does regular. Rather, it allows more aggressive engine designs and calibrations that can extract more power from each gallon of gasoline. The basic low compression 4.0 engine cannot take advantage of those things.

Thinking that premium will save you money and or give you a power advantage is a myth when it comes to the 4.0. And a myth that dies hard.

Save your money.

Some gas stations sell poor quality gas. I find that my XJ do not run good unless I go up to the next higher value which is 89. My XJ will ping on hard acceleration and mileage fall by up to 25% on this poor quality gas. The 91/92 octane fuel does not improve performance or mileage in my XJ over the 89 octane.