Premium gas an who runs what.

DERWOOD

New member
I have a 2008 Jeep jku Sahara and if I don't run premium gas my check engine light comes on I had it tested every time it does it and the only time it comes on is when I run anything other than premium gas it has the stock 3.8 in it and if I run something other than premium it throws an O2 sensor code so all I run is premium Now anyone else have a similar problem?

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silverbullet88

New member
Maybe you have an O2 sensor going out and it will eventually throw a code even for premium fuel? That's just a shot in the dark

I actually only run premium...I feel it makes things..work better


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Ddays

Hooked
Maybe you have an O2 sensor going out and it will eventually throw a code even for premium fuel? That's just a shot in the dark

I actually only run premium...I feel it makes things..work better


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As long as you don't have any pinging or knocking under load running regular gas, anything over that in octane rating is pretty much wasted $$. It doesn't hurt anything but it doesn't help either.
 

cozdude

Guy with a Red 2-Door
If you Jeep is throwing an O2 sensor code than an o2 sensor is bad. This means that your Jeep is running to rich on normal 87 or 89. The higher 93 is burning slower and more completely so their is no left over gas as it passes the sensor into your car. I HIGHLY suggest you get it replaced cause if not then your going to ruin your cats and they are expensive to replace. Spend the $20 on a new o2 sensor. Their are 4. The 2 sensors pre cat are different than the 2 in the cat so just make sure you grab them from the dealer and install them in the right spot. It's very important
 

Ddays

Hooked
^^This! Listen to Professor Coz! I'm having to replace the cats on my Durango (granted it has 200,000 miles on it) and they are $1600 replaced at the dealer & $1200 at my local garage. Those 02 sensors are cheap!
 

rinkishjk

New member
I run premium all the time because I run a screamin demon coil, their wires, and larger gapped plugs, and premium sc tune. Cozdudes advice is correct. 👍
 

jeeeep

Hooked
What has been said about the O2 sensors and also look up your vin for TSB.
I believe there's a TSB on flashing for the O2 sensor correct readings
 

cozdude

Guy with a Red 2-Door
What has been said about the O2 sensors and also look up your vin for TSB.
I believe there's a TSB on flashing for the O2 sensor correct readings

Yes there is one for the egr valve and o2 sensor operation
 

TheGrendel

Active Member
running premium fuel in a vehicle not designed for it or not modified to take advantage of it is a waste. a complete waste.
 

silverbullet88

New member
running premium fuel in a vehicle not designed for it or not modified to take advantage of it is a waste. a complete waste.

Yeah but I'm pretty sure tuner type guys have noticed more knock with lower grades of fuel as well as different brands of fuel. According to their access port or whatever tuner they are using.

So it seems like it could make a difference in a long term way?
In fact there are tons of threads that talk about lower octane fuel causing preignition which leads to poor performance and potentially future damage

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gheller

New member
I had a Ford Taurus with 120,000 miles that needed premium gas (even though it was designed to run on regular) to keep it from knocking. The engine had a lot of carbon build up and other issues so the premium fuel was needed to keep it from killing itself early.

My 17 Jeep calls for 87 Octane, and that's what I run, and it runs great. If you have an engine in good condition with no problems then it should run fine on the gas it was intended to run on. If you've tuned it or modified it, that's an entirely different thing.

One thing I look for now when getting gas is to use Top Tier Gas from listed stations, on ToptierGas dot com. The jeep owners manual brought this to my attention.
 

Hammmerhead

Member
All I run is 87, but I'm not running a tune. How much can you gain with a can tune away? Doesn't seem like its worth it on a N.A. engine and you're just blowing an additional 30 or so cents a gallon.
 

cozdude

Guy with a Red 2-Door
All I run is 87, but I'm not running a tune. How much can you gain with a can tune away? Doesn't seem like its worth it on a N.A. engine and you're just blowing an additional 30 or so cents a gallon.

Really in our Jeeps it's all seat of pants feel. I know when I ran the 89 tune that super chips has it felt the exact same at the 87 tune. I ended up taking both tunes off and just running the stock programming
 

aermotor

Member
I ran premium in my 2007 with a Superchips tune and SD coils.

Now on my 2012 I run 87 as that seems to be the consensus.
 

Hammmerhead

Member
Really in our Jeeps it's all seat of pants feel. I know when I ran the 89 tune that super chips has it felt the exact same at the 87 tune. I ended up taking both tunes off and just running the stock programming


I had a 93 can tune on an SRT Cherokee a few years ago and it made a bit of difference on the clock, but not so much in the seat of pants feel. I don't know of any tunes that really wake up a NA engine.
 
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