Fuel for the jk
 

I posted in a thread earlier about fuel and i said i was using the 95octane fuel, but people told me the jk was built for 87, so i looked it up in the manual and it never mentioned 87 only 91 up to 98, which i didn't understand. So i starting pouring in the 91 octane and i think iam getting worse milege. is that possible and is the 95 bad for the engine? And what do you recommend i use? we have 90, 95, and 98 octane fuel.

US models are designed for 87. It's entirely possible that yours is different based on your location.

You think you're getting worse gas mileage? I would try to confirm it before making any assumptions.

If the manual states 91 up to 98 and 95 was better compared to 91 then I'd go back to 95.

I hate to say it but I thought I nortced the same thing, I went out to Moab last year right after I got my J/K and thought I would treat it and put the good gas in it and it seemed like it did not have as much power and got worse milage. Of course I do not have proof of that but it just seemed that way at the time. Since then I have only put 87 in it.

Higher elevations will have 89 octain.

Burn the 87 octain it's cheeper and what is recomended.

Well iam not 100% sure i got worse millege, but when i fill her up i usuallu zero the odometer and i got 20km less than usual, maybe its because i had a harder foot on the pedal that week, but thats only an assumption. But we all have the same engines don't we? how can the states recommend 87 and here 91 to 98? plus i don't know if i loosed power or if it has actually anything to do with power? but i would want to use the best for the engine, for a longer life.

Moab, because of the altitude, should require less octane. However, I found while in Moab last year that my gas mileage suffered, vehicle performance was "sluggish", and there was pinging. Three different service stations--first time regular, then premium the next two. As soon as we got away from Moab, a tank of premium and the problems went away. I run regular usually. To be honest, the Moab gas is suspect in my book.

There are different ways to measure octane. Since you're overseas, you may be in an area that uses one of those different ways (actually, in the U.S. we use two, then we average them together to get one number that you see on the pump). I'd follow the recommendations of your manual, perhaps confirming it with your local dealer/service facility (they should be familiar with local issues on this).

K, i will talk to the dealer, funny i didn't think of that before, hehe. I don't get any pinging i suppose because it sounds the same. How does a jeep ping?

He is in Kuwait. ALMOST the cheapest gas in the WORLD at .78 cents or so a gallon.

Take note that some countries report the Research Octane Number... The US goes by the Reaserch Octane Number + Motor Octane Number divided by 2 (R+M/2). so you can have a 95 octane RON, if the Motor Octane Number is about 80, you'll be equivalent to the 87 US octane rating.