Can someone explain this E85 for me? As far as I know the evo requires 91 octane or higher. Some of you run Ethanol 85 gas, yes? So, if available in my area, I can get a tune for E85, and expect to get more horse power out of it then 91 octane?
Also, does the car use more fuel running on E85?

 

Yes, the car uses more fuel on E85. You generally need upgraded injectors and an upgraded fuel pump to run E85 since you need to burn more of it (roughly 15% if I'm not mistaken).

 

I see..
So then, from what I've read so far, to get better fuel economy out of the X, different intake, better tune?

 

evo and fuel economy should not be in the same sentence but yes a tune would help...cobb has economy maps for the AP too

 

k, thanks.

 

I run the economy maps on the AP for my daily commute. Makes a difference by a lot. Like 25 to 30 mpg, but no power lol...

 

I keep seeing people talking about oil catch cans and selling them. Heard with me running E-85 it would be a good idea to get one, why?

 

I think its a little bit more towards the 25% area for e85

 

The oil catch can keeps oil being drawn back into the intake system through the positive crankcase ventilation (PCV) system. On boosted cars (or any car with bad compression seals) the combustion pressure leaks into the crankcase and blows oil with air as it is drawn into the intake for emmsions (it used to just be vented to the atmosphere).

Short answer - if your intake system is clean, with no oil fouling - then you do not need an oil catch can.




(yet)

 

How does one know if the intake is clean?

 

You take off the intake and check if it's clean.

 

Can I just short the fuel pump relay so it's always running at max voltage and not deal with a faulty relay blowing the motor?

 

No.

The pump would run even with the car key 'off'...

It is also for safety - computer shuts it off in a roll over/collision...

Best fix is a new relay.

 

so totally off topic but I just bought a 09 GTS and am weighing pros and cons of different upgrades. I want a good performance boost but don't want to kill my mpg (this is my commuter) what upgrades will benefit me the most?

 

You'll have better luck and more people familiar with your platform in the Lancer section.