RescueG911

I've been using 87 for a while , but was thinking if higher octane would be better?

blue project

I did the superchips program with 87 and saw a bit of a difference. Swithed to the 93 tune and got more power and less mpg's. Now back to 87 and not really a noticable difference in the power, mpg's are going back up a bit. Not to mention the price difference is $0.25+ per gallon for the 93.

Desert Drifter

I've only noticed pinging when wheeling, perhaps because of the engine demands while going up steep grades.

So I fill with hi-test when wheeling, 87 for around town.

33 williys 77

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RescueG911

Ya I just filled up with 89... I'm gonna see if it makes a different. I've been experiencing some lag, hard to describe... What exactly is pinging?

33 williys 77

Pinging is pre ignition another words a hot spot in the combustion chamber cause by deposits set the fuel off before the spark plug fired and octane has nothing to do with Detergent

Rednroll

How does 91 octane clean out the engine? That doesn't make much sense considering 91 octane requires higher combustion for it to ignite than 87 does. The JK is tuned from the factory for 87 octane, the electronic ignition system is programmed to function at optimal capability with 87 octane and you should only really use a higher octane if you notice misfiring and pinging. 91 octane does not clean an engine and higher octane does not mean cleaner gas....detergents clean engines which are not tied to the octane rating. If anything using a higher than 87 octane gas can have a negative impact by damaging your emissions system and you are therefore actually throwing dirt into your engine when using the 91 octane rather than cleaning it.

Your owners manual says to use 87 octane because that's what everything the engineers who designed the JK engine programmed everything to work at for optimal performance. So you're actually doing more harm than good by running a higher octane fuel.

There's a lot of misconceptions about using higher octane fuel. A lot of these misconceptions are based off of old school knowledge of carburetor combustion engines with the use of higher octane fuel, where the JK engine is a computer controlled fuel injected engine where the same principles do not apply. Reading this thread confirms these misconceptions.

It would probably be pretty interesting asking some of you for further background details as to the reasons you chose to run higher octane fuel. I'm willing to bet that most of those reasons could be debunked with a little background research.

Greep

I run 87. No advantage with OBDII computers to run higher... I also use a bottle of RXP every 8 or 10 tanks. My Jeep is still new, so its preventive to keep carbon from building up and to clean out any ethanol through complete combustion. If you've got some mileage on yours, I suggest running a bottle of it on your next fill up... you'll be surprised.

JackDANJK22

& people like you ! Are the reason my dumbass is here sir !!! Thanks for all that information ! Was about to go fill up with some 91 ! Thanks !!!

sringer

That's what I do. Sooo nice. About to add a sprint booster too