It was a long time ago but if I remember from one of my Organic Chemistry classes, water is loosely considered to have an Infinite Octane rating. In my book, infinite octane is >93 Octane so it would offer the best economy and most power...fill er up !!


The big question is does the JK use a knock sensor? If it does, there is an explanation for the increase in power and/or increase in economy. If the sensor detects knock it will cause the ecu to limit ignition timing thereby reducing power and efficiency. If the JK does not, then the longer and more stable hydrocarbon chain of the high octane fuel should not work as efficiently as the shorter chain less stable low octane fuel.

 

Kids these days.

 

I was hoping to find lower octane and try that.maybe 82 or something!!!

 

Didn't Peter do this in a Family Guy episode (cost Quagmire his job). His "redneck" 4x4 truck actually flew !!! I would think a lighter and smaller Jeep might even be able to make it to space ...

I double dog dare ya ... and please post your results

 

I've always used 91, not a problem with my jeep. yes it does feel alot better than 87 thats forsure. I feel better putting cleaner gas in my cars

 

The butt dyno can't be trusted. Does it feel a lot better wasting money?

 

OLD thread...


I don't think higher octane means cleaner gas.

 

For anyone who believes that higher octane fuel nets 2-3 MPG, I have a source for Bio-Performance Fuel Pills that will net a 25% mileage increase, or so they say.

Also anyone who claims to have more knowledge than the factory on how to optimize their Mileage/Performance on a bone stock unit in regard to fuel management, is also whistlin' in the wind. Specific scientific reference would be a start.

 

I find it humorous all the folks here tauting that the Manufacturer knows best.

I wonder how many of these same people use Synthetic oil and a larger filter and have installed a CAI But the owners manual wouldn't lie...

For the record I believe 87 works just fine........just think its funny

 

You can cause damage to your engine using a higher octane fuel. It's called predetination, which means your cylinder is firing before it gets top dead center which in turn damages valves. 87 is what the engine was setup for, so thats what I would run.