Hi:

I'll be lurking this forum forever but this is my first post.

I am very close to purchasing a new Evo X. However, one thing that brothers me a lot is that Misu's site clearly states that the car requires 93 octane but where I live (California) these are very hard to find.

I tried searching and come up with threads such as this: https://www.evolutionm.net/forums/ev...93-octane.html

Most replies often suggest that 91 is ok but put in 93. There isn't a definite answer.

So my question is this. If I buy in Cali, is the stock car tuned to run on 91? Would I be getting knocks all over if I continue with 91?

Or should I just get it tuned for 91 as soon as I can? Or may be download some off the shelf maps right the way?

 

You would be okay on 91 octane, but the car would have somewhat decreased performance. For optimum performance the car would need 93 octane. Mechanically speaking, you wouldn't be in danger of damaging the engine running on 91.

 

You'll be fine on 91.

 

been running 91 for over 100k miles now with basic bolts. no issues.

 

Get it tuned on 91oct to assure there's no issues.

 

PNW here. 91 is okay for me as well.

 

Of course 91 octane will be fine. What do you think everyone else in California has been pumping into their Evos?

Be glad you're not in Alaska though -- don't they only get 90 octane?

 

been pumping 91 octane for 10k miles now. WOT almost everytime I drive it. I would say its okay

 

Stock cars are tuned with enough of a safety margin that even if you put regular in, it should not harm the motor. However, the best thing would be to get it tuned for the octane you will be running. If you get a Cobb Access Port, you can use one of the pre-programed 91 octane tunes.

 

I ran 91 for about 300 miles.. had no problems!

 

Get it tuned on 91 octane to be safe.

93 octane will just increase performance.

 

Been running 91 for 2k and no problems, but then again i got it used haha

 

Welcome to CA. **** water 91 for us only. Unless you wanna switch to E85.

 

This may be a silly question, but I just found out there is a 94 octane station near me, other options being 91.

I just bought a 2014 Evolution X GSR in Washington (where the premium is 92) and now live in California, where the normal is 91.

If I drive a few minutes away to a station with 94, can I use that and will it be better than 91?

I just really want to treat the car well right now. Its got less than 3k and its my first stick and my first really cool car.

 

I'd stay way from the 94 unless you get tuned for it.