Should start a gas poll.

I refuse to use Arco or crappy gas.

Shell, Mobil, Chevron, or 76 only!

 

I used to put 87 Regular in my old XJ's and they ran perfectly fine. JK gets the same

 

With aluminum heads, these engines will run on regular approaching 11.1 compression. Aluminum dissipates heat far greater than iron and the combustion chambers run so much cooler that they will actually war off any detonation. 87 octane will be fine. It's what the engine was designed for.

 

Yup, The use of higher octane fuel is a waste.

 

I only use sunoco. In my Cobra it gets detonation on anything else except for a few BP and Exxon stations. Never had any issues with Sunoco.

 

I use Premium Unleaded in my JK, but purely because most regular unleaded these days (where I live anyway) is a 10% ethanol blend and results in lower power and much poorer mileage. I don't think the 95-98RON Premium results in any more power than regular (non-ethanol) 91RON unleaded though when run in a JK 3.8 V6; not that I've noticed in mine anyway.

 

The ethanol will give less fuel economy in some cases, depending on the amount of ethanol mixed in. If we could get custom tunes for our JK's pcm we could change the commanded afr to match the stoich point of the E10 fuel since it's different that the gasoline stoich of 14.7:1. I believe stoich for 10% blended fuel is 14.2:1 so if we could tune for that the fuel economy would come back for the most part. It sucks not having the aftermarket tuning ability there is in the Mustang world. Give me a sct handheld and Pro Racer software and I can chage about anything on my Cobra.

 

That's not what the pumps say. READ them. They say UP TO 10% blend. That means the refineries can blend ethanol or not, and at whatever percentage up to 10% they want. Also, you have been misinformed about ethanol if you think a 10% mix will make power drop off. In fact, ethanol actually can help make more power. With it's cooling properties, it can help cool the intake charge and pack more air anf fuel into the cylinders. I can go on and on, but you won't be convinced unless you research it for yourself. You really should. Lastly, I would suggest that you go to your local dragstrip and do a comparison on the different fuels. I bet you a dollar and a doughnut you ain't makin more power on super. You're just wastin your money. It's certainly your money, though.

 

Might want to point out that JKLad is in Australia, so I would guess the fuel is different over there ...

 

X's 2 on this.

If you want to clean out deposits open up your Jeep on the highway once in a while. And that's if you just mostly putter around town at low speeds.

With today's high detergent lead free gasolines, deposits are just not that big of a problem