Originally Posted by ianto303
Hey guys, I drive a stage 2 2011 sti. Dp and accessport. My car is not tuned for e85 but I heard it was safe to add e85 as long as you put the right ratio or just not too much. Is this perfectly safe without any damage to the car? Does anyone do this? I heard it can give you a Lil more power and the ratios I was hearing are maybe 60% 91 Oct and 40% e85 or maybe 50-50. If anyone can please give me more info I'd appreciate it I wanna give this a try.
It will give you absolutely no more power because the car is not tuned (ie timing and boost are not tuned) for e85. You can make significantly more power on e85 because you can run more timing and boost due to the great knock protect the fuel allows. As far as adding e85 to your tank it's best not to due it. If I remember correctly I've read a 30% e85 70% petrol blend would be considered safe, but even then I'd really want to log the car to make sure the fuel trims aren't all out of wack. Honestly I don't think it's worth it though. There are inherent risks in messing with a new fuel blend that you are not correctly tuned for, and the benefits (more knock protection) really wont do much of anything as long as you are properly tuned for the fuel you currently run. If you want to run e85 I highly recommend it, just do it the correct way.