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Discussion Starter · #1 ·
My area only has 92 Octane premium. Can I run the 93 Octane tune on my stage 2.5?

Is there a particular humber I should keep an eye on in the Cobb Accessport to make sure timing isn't being retarded as a result of the 1 point lower Octane?
 

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Watch your "octane adjust ratio learned" (OAR). It starts at 0.0 and will move up to 1.0 if you use good fuel that is the correct octane. I'm no expert, but you might be able to get there on 92. Some people add a gallon of e85 for a little octane boost, so that may help.
 

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Discussion Starter · #4 ·
Watch your "octane adjust ratio learned" (OAR). It starts at 0.0 and will move up to 1.0 if you use good fuel that is the correct octane. I'm no expert, but you might be able to get there on 92. Some people add a gallon of e85 for a little octane boost, so that may help.
Good to know! I just googled, and it looks like according to Cobb, it should actually be -1.0 optimally. Unfortunately there is no E85 within an hour of me :/
 

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No, you cannot run a lower octane than what your tune calls for.
This ^

You can go higher, not lower.

Going higher leaves headroom for your car to have plenty of octane to work with and never have to compensate, having lower means your car has to adjust and compensate for that..which is hard on the car considering it's tuned to run a powerful calibration with MORE octane. Don't risk it.
 

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And indeed even some 93 is not quite 93 as far as the tune may be concerned.

Want some safety? Run 93 gas with a 91 tune.

But NEVER run a tune that requires a higher (R+M)/2 octane than what you have a available.

Mark
 

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Short answer... No, you cannot.

Longer answer... Maybe... If the 93 octane tune was tuned on the edge of knock by the tuner, you will have problems and possibly damage the motor. If he was conservative in the tune with timing and boost, there should be enough head room to not harm anything.

If it were my car... Get a tune for the gas you will be running.
 

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A 91 tune would be best as people are saying. Depending on the tuner, you could definitely be getting some knock.

I know stratified does datalog refinement and yours would be refined around 92 fuel based on your data logs. So you get the base ots tune, do some pulls or whatever they ask you to do using your regular location specific fuel, send them your data logs and they send you a map specific to that fuel. I'm sure other companies do that too, but using stratified as an example, contact them, tell them your story, buy the 91 tune and see if they can adjust it to 92, or see if they can adjust the 93 tune to 92. Stratified charges $100 for the refinement tune.
 

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Discussion Starter · #10 ·
Thanks everyone for the consensus! Sadly there isn't any 93 or e85 near me, so it looks like I'm stuck with 92 octane and the 91 tune. I appreciate y'all!
 
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