In the Chicago area I use 87 and average 15 city mpg. Not bad, but not good either, would love 18-20 mpg city

 

E30.

 

I avoid the ethanol crap like the plague. Straight 87 octane NON Alky gas really makes the 92 XJ happy. I really notice the mileage drop when I buy the cheaper 91octane gasohol. 10% ethanol.

I tried 91 octane 10% ethanol in my bike last summer. Ouch. You can really feel the power loss from the alky. I could re-jet to bigger mains, but why? Would use more fuel and the cost savings would disappear.

Shell 87 octane seems to make all my vehicles happy. Paid 3.59 (5/8/13) last night per gallon of non ethanol.

 

I try to get non-ethanol as much as possible, I notice a MPG increase with staying away from ethanol.

 

i was not in caps lock, there was no yelling :P but i still stand by my previous statement. i really dont think that in our jeeps, running gas from any station is going to make a huge difference. Grade makes a difference sure, but from station to station, not so much. As long as it is a well used station and the fuel tanks are constantly renewed our 4.0's should be just fine.

 

Yeah ethanol kills my mpg like crazy. I mostly just get 87 and speedway.

 

With 87 octane, unless it specifically says no ethanol, you are most likely getting 6-7%.

 

Yes, you have to specifically look for a gas station that is selling "non-ethanol" gas.

 

So do the higher octanes have less ethanol then?

 

Depends on the blend. Ethanol improves the octane rating of a fuel. Up in these parts there's some 94 octane rating fuel at Petro-Canada that has a ****load of ethanol in it. Conversely, Shell's 87 is 10%, 89 is 5%, and 91 is ethanol free. Most marina gas stations only sell ethanol free.

The only way to know is test it or call the manufacturer. Or, so-called "crowd sourcing" way: http://pure-gas.org/

 

In the U.S., the highest registered blend that you can buy, and that is not sold for flex fuel vehicles only, is E15. Normally, the highest percent you'll get is 10% using a mid grade and possibly a higher grade.

 

Then stand by and chuckle watching folks add a bottle or two of HEET to it.

There is only 1 station left around here with ethanol-free gas, and you have to buy the premium grade to get it. I haven't noticed much difference either way in the XJ.

 

The stock 4.0 does just fine on regular (87) octane gas. Octane is an anti-knock index. Nothing more.

Use what your engine was designed for. The myth that higher octane is better has been around for a long time and refuses to die.

 

What are you doing up? Radi is supposed to post at 1:55 AM, not PM!

 

Happy now?