It probably won't make a difference at all. It might help clean the fuel system, which could be noticeable if you haven't done that in awhile, but not like running a bottle of injector cleaner (which is mostly just super-high octane fuel and extra detergents).

 

This is what I was told by the dealer besides a bottle of cleaner to clean out trash in your gas tank.

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Back in the day when premium was only a penny or two more, I always ran premium. The better MPGs made up for the cost. But today, I doubt that would be the case.

I've had many cars that were labeled, "Premium Fuel Only" too, and glad I don;t have to do that today.

I doubt the premium will do much for you, especially with the motors tuned for 87, but I doubt it will hurt either.

In Stihl saws, etc. they recommend premium fuel for their equipment. They also prefer you to use fuel with no Ethanol too. I wish I could find no ethanol fuel for it, and I would prefer that in the Jeep too.

 

Supposedly these stations offer ethanol free gas which is what you want for small engines - for your Jeep, it would probably be cost prohibitive:

http://pure-gas.org/index.jsp?stateprov=AZ

In Stihl saws, etc. they recommend premium fuel for their equipment. They also prefer you to use fuel with no Ethanol too. I wish I could find no ethanol fuel for it, and I would prefer that in the Jeep too.

 

A few weeks ago, I ran about 3 tanks of 89 rather than my normal 87. I didn't notice much of a difference just slight accel, more of a placebo I believe. If it helped clean up the I switched back to 87. I've never ran cleaners, which I probably should so maybe those few tanks knocked some of the gunk out.

 

Just thought I'd clarify, the only thing I was wanting to use a tank or two for was to clean it out. Would I just be better served to run a dedicated cleaner through?

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I would think so, yes. The cleaners are usually about 109-110 octane, and as stated, contain more detergents.

What I like to do is get down to a low amount of fuel, dump the injector cleaner in, and drive it like that until the fuel light comes on. This way, the injector cleaner is diluted as little as possible by regular gas, hopefully giving the maximum benefit.

 

Thanks everyone for your replies!

 

I ran Sunoco Ultra fuel(from the Sunoco across the street from college) for the most part for a few months after getting mine, but costs got me to quit. Didn't seem to hurt it, if anything it probably ran better. Since putting in the intake and exhaust I've been running alot of midgrade though, trying to make it run better.

 

Vehicle is designed for 87. Running premium won't do anything and actually can return worse MPG. See page 367 of your 2012 OM.

If you want to do a cleaning run grab a good FIC( RP MaxClean, Techron +, Gumout w/ Regane, etc... )and do that. I wouldn't waste the $$$ on 90, 91, 93 etc...

I admit once in a while I will run 89. However, that is when I am towing my duck boat and really taxing the engine.

 

The only time I run anything other than 87, is when I go to visit my family in utah, and they have 85... I won't run that through any car, so I run 89.

"The octane rating of gasoline tells you how much the fuel can be compressed before it spontaneously ignites. When gas ignites by compression rather than because of the spark from the spark plug, it causes knocking in the engine. Knocking can damage an engine, so it is not something you want to have happening. Lower-octane gas (like "regular" 87-octane gasoline) can handle the least amount of compression before igniting."

(from http://auto.howstuffworks.com/)


So you should put in the octane that is recommended for your vehicle.

 

The only time I run anything other than 87, is when I go to visit my family in utah, and they have 85... I won't run that through any car

85 is all I run. Thats standard gas around here at this elevation. Anything more is just wasted money in a 4-banger

 

My manual does say to use higher octane fuel when going off road though, for the FDII. But I have never done that.

 

That is true, it also states in the manual that in the FDII offroad mode the engine timing is advanced for more performance, I can confirm this is true with my scanguage2 the timing is increased by a few degrees when put into the offroad mode.

 

My old S10 started limping cylinders badly, Plugs were good, had to be injectors (poppets in those). I took it to a shop to have it diagnosed, as home diagnostics aren't very good on FI. They tried to sell me a full injector rebuild for 1300.00. I left, went to Napa Auto Parts, got some Napa brand injector cleaner and dumped it in with about 1/4 tank left and took it for screaming hot laps on an old empty road. The next morning, it was hitting cleanly on all 6 and never gave me any trouble after that. The stuff DOES work......but so does running a quality fuel that has Techron already in it. Octane rating doesn't matter much if your rigs designed for regular.

 

Yeah, $1300 sounds about right for a rebuild, considering the complexity of "the spider"... glad it didn't need it after all. :smiley_thumbs_up:

 

my first car was an '88 mazda 626, had about 300k miles on it. The injectors would get clogged and I had to put in a bottle of lucas "tune up in a bottle' every 3-5k miles, so I bought them in bulk. ( I did A LOT of driving as a teenager) and it was like night and day when I needed to use it.

 

Seafoam is great - handy when the wife puts 87 in the Landrover and throws a code (since it requires premium). Remember premium has to stick with whatever high octane limit or higher the manufacture states however unleaded 87 octane vehicles can run anything above 87. Rule of thumb, you can go up but not down with octane.

Also you can get ethanol free gas anywhere here outside of the metro counties where its required and I was pretty sure it was the same across the US.

 

Many areas mandate E10 regardless of octane rating or location. All gas sold in NH for vehicles has to be E10. You can get regular gas at a couple small airfields for planes but don't get caught running it in your car.

 

Round here only metro Milwaukee is mandated to use E10 and the rest of the state (90%+) does not. They tried to put a bill through mandating state use but it kept failing to pass. I try to get gas in the country near work when I can, usually cheaper and ethanol free.

http://news.heartland.org/newspaper.../newspaper-article/2006/05/01/wisconsin-senate-narrowly-defeats-ethanol-mandate

 

When I can fill up with non ethanol gas, my mpg improve, my engine runs better (especially my older alero) I have more power... I don't know why they insist on putting corn in our tanks (except for the fact that lobbyist "helped" the government to make that decision).

But that's a different discussion all together.

 

Yeah and the stuff breaks down to water so guick. My daughter moved back in for a short while and brought a container of it with her. I fueled and killed both mowers with it this spring because it had so much water in it. Had to tear down and drain both motors. I threw the remaining "gas" on the fire I was using to burn of a pile of brush and it DID NOT ignite, crazy!

 

Here in my town you can actually go to the local fuel transport company and get non ethonol or so I've heard but its like .30 cents higher per gallon then regular. Also there is one small service station that has it but he Is like .40 cents higher and as long as he has been in business with the same tanks i worry about rust in his fuel..

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I find when I use premium Ultra Octane 94 at the Petro Canada around me, I get an extra 50kms per tank on average. Well worth the extra $7 per tank. For awhile I was strictly filling up premium.

 

I went ahead and opted for a container of seafoam. Here's to a gunk free engine epper:

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how many miles do you have? you should not have gunk issues with the age of your vehicle... seems a bit excessive to me.

 

On a low mileage vehicle you can probably read the directions...for instance a single can of Seafoam will dose a Patriot fuel tank three times...and get away with spending less money.

Single best thing you can do, after proper maintenance, is use the vehicle. Take it out and let it really warm up, go for a run. Short trips and pooting around town is hard...a romp down the highway is good.

Most modern fuels blends will look after your injectors and if you change your oil/filter on schedule gunk won't be an issue.

 

Found this site helpful in locating ethanol-free gas stations: Pure-Gas.org

 

I run a bottle of Gumout Fuel Injector cleaner through mine with every oil change. Over five years and 125K miles and no issues with anything in the fuel system.

 

I should throw a can of seafoam in my commuter - close to 200k now.