JKJeremy

personally, i put the cheapest gas i can find in mine....runs fine...never had any issues and no differences that i can tell in performance between the different brands.....always done this with all my vehicles...only ever had one that was picky about the brand you put in it....i'm fairly convinced that with modern cars you could practically urinate in the tank and the computer would compensate enough for it to run especially after a night of drankin'

Lorrel

Regular gas (87) for our Jk + a bottle of injector cleaner at every oil change.
Ran a tank of 89 octane one time and saw no significient changes either way.

Matt08jk

As I understand it. . .

Octane levels have largely misunderstood linkage to "power".

Despite the ads and what the bottles say at the parts store, adding a bottle of octane booster to a vehicle designed for reg. 87 will not create more power.

The link is that Octane is an adgent in fuel that resists detonation in the combustion chamber and usually higher HP engines are the higher compression/forced unduction engines that require the higher octane fuels to calm down the potential for detonation.

Sometimes the facts get blurred, but in a stock JK engine (and stock engine programming), regular 87 octane is the best, anymore and you are tossing money away.

RedneckJeep

Sorry dude. I missed your location. Things could be way different there.

Thanks amt97 for pointin that out.

BigEarl

With the Hypertech set on regular our JK gets better mileage with mid grade than regular. According to the math it's worth the extra pennies.

spartan99

I like my gas the way I like my women. Cheap. Also, everything I need can be found at a gas station:

Bathroom- check
Snack- check
Gas- check
That cheap prostitute on the corner- why not you only live once- check

JKlad

Yeah, no worries! here in Oz, the 10% Ethanol rating apparantly means that the fuel contains an "average" of 10% ethanol, so it may be higher of lower within a certain tolerance. I have no idea whether it's because the hot weather down here causes the ethanol to seperate from the petrol in storage causing variations (the same way oil will seperate over time in 2-stroke fuel), or because the oil companies don't feel comfortable in guaranteeing the 10% limit (in case of litigation)

A few years ago, before the big oil company-owned petrol stations started stocking E10, it was mainly the small, independent stations that had ethanol blended fuel and since pure ethanol is cheaper than petrol (here, anyway) some of the wholesalers supplying these independents were adding up to 25% ethanol (and selling the fuel on to the retailers for the same price, making a tidy profit in the process) it was later found when an inquiry was launched.

The result was that many people who used this fuel were finding their injectors & EFI systems failing after just a few tanks of the stuff, with mechanics citing this as the cause. For years afterwards many fuel stations in the suburbs where this problem occured even had "No Ethanol; guaranteed!" signs on the pumps (some still do). So I guess that's why ethanol still has a bit of a bad name here.

In my previous vehicle, a '95 Ford sedan, I found using E10 resulted in very rough running, noticable loss of power and torque and a big (20%) reduction in mileage, so I stopped using it. (I understand this was because it was an older vehicle with many miles on the clock for a start, and the older ECU computers weren't as adaptive as the modern ones at detecting different fuels and octanes and making mixture and timing adjustments accordingly). Maybe all this explains my reluctance to use ethanol blends if I can avoid it, which unfortunately means I have to use the premium unleaded which does not (as yet) contain ethanol here apart from one brand.

Anyway from what I've heard, eventually most new vehicles will be E85 capable, so as the engines will be designed on the drawing board to run on high ethanol blends from day one in regards to fuel system & combustion chamber design and ECU programming, they should perform no differently regardless of blend in regards to mileage and performance.

pearl-drum-man

I've always just run the 87 octane.

jkkat

With RubyDoo i found out that when going wheelin she does not stall useing super and when i use regular unleaded she stalls when i lug her out.

999666

Yes, cause of this with older vehicles is that the seals and often the gas lines themselves were drying out , disolving and cracking due to the ethenol content.
Newer cars supposibly use ethenol resistent seals now.

Not a fan of the 10% blend some stations have here in Canada either.
With less energy then gasoline per volume, to me it's like watering down the fuel and charging the same as pure gasoline as you already mentioned.
One + for ethenol though, mixed in it does lower emmisions.