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Discussion Starter · #1 ·
Hey guys have some questions that I can't seem to find the answer to. And before anyone goes "SEARCH FUNCTION USE IT NOOB OMG WTF IM SO ANGRY ON THE INTERNET!!!" I have searched and couldn't find a definitive answer so I thought I would post and consult you fine folks. So I have a lightly modded '13 ST (a Cobb intake and the Cobb 93 tune). I am taking a road trip to the west coast at the end of the week and know that finding 93 octane gets harder the farther west I go for some darn reason. My question is will I be ok running lame ass California 91 octane on my 93 tune or will I run into issues? Should I detune down to 91 or even 87 for the trip? From what I have been able to learn about fuel grades and knock resistance I'm thinking that I should be ok running 91 on the 93 tune for a week as the Cobb ots tune is pretty conservative and I'm not heavily modded and running a boat load of boost. Hoping you guys can chime in and either confirm my theory or educate me as to why I am mistaken. Thanks in advance for the help. :)
 

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2017 Ford Fusion Sport
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Hey guys have some questions that I can't seem to find the answer to. And before anyone goes "SEARCH FUNCTION USE IT NOOB OMG WTF IM SO ANGRY ON THE INTERNET!!!" I have searched and couldn't find a definitive answer so I thought I would post and consult you fine folks. So I have a lightly modded '13 ST (a Cobb intake and the Cobb 93 tune). I am taking a road trip to the west coast at the end of the week and know that finding 93 octane gets harder the farther west I go for some darn reason. My question is will I be ok running lame ass California 91 octane on my 93 tune or will I run into issues? Should I detune down to 91 or even 87 for the trip? From what I have been able to learn about fuel grades and knock resistance I'm thinking that I should be ok running 91 on the 93 tune for a week as the Cobb ots tune is pretty conservative and I'm not heavily modded and running a boat load of boost. Hoping you guys can chime in and either confirm my theory or educate me as to why I am mistaken. Thanks in advance for the help. :)
Yes, you will run into problems. Use the Cobb 91 ots tune for the time being, and then switch back to your 93 tune you usually use when you get back. Absolutely do not use 91 on a 93 tune

Edit: I put super garbage 93 in my tank that apparently wasn't 93 at a 7/11 in Virginia and had HUGE ignition corrections and knock. I said screw that and put it down into an ots 91 tune for the time being and babied my car for the duration of my trip.
 

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Discussion Starter · #3 ·
Awesome! Thanks for the quick reply. I'll switch the tune before I hit the road. Out of curiosity what sort of problems would it cause?
 

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Awesome! Thanks for the quick reply. I'll switch the tune before I hit the road. Out of curiosity what sort of problems would it cause?
Your car would knock extremely bad and it would have to pull a lot of timing in order to compensate for fuel that isn't good enough for the aggressive tune you're running. I saw ignition correction pull 8 degrees of timing in every one of my cylinders lol my knock count was like through the roof. Not good at all. I immediately pulled over because the car was running like absolute garbage and then I looked over and saw my accessport giving me all those corrections and I turned the car off in the parking lot and I changed tunes right then and there.
 
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