Had a moment of stupidity on Saturday. Went to fill up the car, got 2 gallons in before i realized it was mid grade 89 octane. I finished the fill up with 93 octane (10 gallons). It doesn't feel like the car is knocking or is any slower, I just have to get all the gas out b/f thursday b/c I'm going to AMS to get stage 1 done. How bad is this gonna be for the car and should I run injector cleaner b/f I fill up next time?

 

I would think that what you did was completely harmless. The car is designed to run on 91 octane (this is all I can get in California). 2 gallons 89 + 10 gallons 93 = 12 gallons @ about 92.3 octane. You're fine.

 

If you calculate it your gas tank is averaged at about 92.467 octance, which really won't make much of a difference, just try to use up some gas and fill up on 93, or if your really paranoid, you can put in 1 gallon of unleaded 110 octane and it would more then even it out for you.

 

fill it w/ 5 gallon of 100 octane and you will be ok

 

Running on 89 Octane's not going to do any damage. You probably wouldn't even notice a difference if you didn't do any spirited driving.

 

I did the same thing on my bike, though i didn't even put in half a gallon before i realized it, wont hurt it too accidentily put 89 in 1 time and barely put any in it.

 

yea, you should be alright, one of my friends did the same thing in a 350z and he didnt have any problem..

 

Dont worry its not that bad. Nothing will happen. All I run In my car is 100oct baby!

 

watch OUT!!!!!!!!! you motor gonna blow up!!!
































j/p, you'll be fine!!

 

Actually, 89 octane may cause you to throw a code. I did the same thing pretty much, and my car went into limp mode. I also experienced a couple misfires. You might need to get a code cleared before your tune, but that's not a big deal.

 

this situation might happen only if he fill 89 the whole tank.

 

your ecu will compensate and and allow the engine to run on degraded fuel

 

According to the owners manuel that I got here in Ohio, it is designed to run on 93 Octane only.

 

No it won't. Where does it say this? You will just get misfires and can do damage to the motor.

 

Your on it Dayton. My 05 Evo MR indicates a minimum of 93 Octane. What's funny is how it tells you it's OK to use 92 if 93 isn't available. I believe it then says 91 is OK if 92 is unavailable. I gave my local dealer a hard time as I received a voucher to go fill up the tank after I picked up the car. The fuel station I went to (and had the voucher for) only had 92. I ripped on my dealer for violating the owner’s manual with 5 miles on the odometer.