Compared to running anything higher like 93+ how much will this low of octane hurt the Evo in performance?

 

no no no no no

 

Well 90 is all we get up here so...Yes yes yes lol.

I can mix some 104 race fuel with some 90 and get it higher if I need to but that's going to cost an arm and a leg.

Also how much performance loss does 90 octane hinder our evos?

 

low octane + high boost = BIG risk

dont do it.

 

OK well I learned my lesson...No more pump gas for me. I hate having 90 octane it's horrible, I wish we had 92-93 like other states.

 

Where do you live that only gives you only 90 octane? Our California 91 octane is also pretty bad. Water and Alcohol injection is the only way I've been able to get my last 2 turbo cars to perform decently with our crappy 91 octane.

 

yeah where do you live?

 

Alaska...Yea it sucks *****..90 octane makes the Evo run like complete crap...it really feels like it's holding this car back.

 

damn adn i thought we had it bad over here.

 

I don't think it's going to hurt anything more than the 91 I'm using here in AZ. The car does have a knock sensor so it will pull timing and maybe other ajustments so it will run safely on that fuel. The result is power loss. But your engine won't be hurt by it, that is if you have the stock ECU running things. With aftermarket stuff, you would have to tune for that fuel.

Personally, I wouldn't want to mess with race gas. Get a water/meth injection system and all the other suff you need to go along with it (i.e. some form of engine management). Think of water/meth injection as "octane on demand".

 

Yeah, 90 octane sounds pretty bad. They've actually tested our crappy California 91 octane premium to as low as 87-89 octane in the past. The IX has superior knock control compared to the VIII, but higher octane or a good water/alcohol injection system will definitely make your Evo perform better.

 

Wow what a relief I was really getting dissaponted by the EVo's Performance...it was just lagging BAD!.

 

I wouldn't be worried about lagging performance on 90oct - I'd be worried about blowing the engine. That is simply not enough octane for the Evo, and you should put at least 1 gallon of 104 in your tank everytime you fill up. That will only make it cost an extra $2-3 each fillup, which is worth it. 1 gal of 104 with 13 gallons of 90 would be 91oct.

 

I actually have 5 gallons of 104 left over from what I used on my Supercharged RSX...I'll throw 2 1/2 gallons every fill up so I can see atleast 93...

if I had a stand alone I would be able to street tune myself for 95-100 octane.

 

You don't need a standalone to tune for 95-100oct. You just need a big wallet to buy that much race gas then use EcuFlash, which is free software.