I recently tried running the next octane fuel, 89, in my jk on a roadtrip. I noticed a two or more mile per gallon increase and i was wandering if running this fuel can cause any problems?

 

2 MPG increase solely due to using a slightly higher octane, or as a result of road trip / driving conditions / type of driving?

 

I run super in mine all the time and get 17-18 with my 285/70's and can tell the difference at the pedal and fuel gauge.

 

Ive tested my mpg on the same road trip a few times, and Ive always got 15.6. This time i was getting close to 18.

 

I get 17-18 in my 2011 running the cheap crap

 

but with they way prices are going do you still think its worth it?

this past winter i got a flash pack and changed the settings to run the middle gas quality 91? 93? and i def felt like it helped. but thats when i was getting it for 3.10 a gallon now that the cheap gas is about 3.40. im not sure if i am going to switch back. what do yall think or what you doing

 

ive got a 2011 sahara 2 dr 6 spd with 33x12.5x17's BB and nothing else getting around 15mpg on the trip computer, tried premium 93..same ..i dont waste my money

 

Same jeep same story. I throw some 93 in with some FI cleaner once a quarter and no difference still

 

I am with "Im-OCD" on this one. Not likely to get that much difference on the octane alone.

 

I just don't see how a higher resistance to detonation under compression can give better mileage. It was probably just trip conditions. Unless your timing is tuned or you stroked it or added some sort of forced induction, I don't buy into the idea.

I am going to try it though. My math says 1 more mpg on gas that 3.69 as opposed to 3.49 I will just about break even. So anything more than 1mpg I'd be saving a tiny bit of money. Am I right here. As gas goes up in price the +$0.20 becomes negligible and I'd save more. But will that gap in between octaves go up too?