I heard from a reliable source that they run E85 in their XT and get more horsepower with no downsides. They mentioned something about E85 having a higher effective octane than regular unleaded. Is this true, or is there more to it?
If they have tuning and a flex fuel kit, it’s possible. Without those, they’re just talking nonsense.
Totally true! Both my Forester XT’s run on E85. You’ll need bigger injectors, a larger fuel pump, and a proper tune. It can give you an extra 20-40hp, but the real gain is in torque, which can increase by 70-100 lbs. I have one daily driver with 420 whp and another beast making 715 whp. Good luck with your project!
There’s more to it. Horsepower doesn’t come directly from octane. It’s about the fuel, time, and engine efficiency. They should mention all the modifications they’ve done because this stuff isn’t cheap.
You can run E85, but you need the right kit (injectors, fuel pump, etc.) and a tune. Check out WRX forums for more info—lots of WRX owners run E85. Don’t try it without the supporting mods, though, since the engine is only meant for up to 10% ethanol.
That could damage the engine. E85 increases fuel flow, and the engine isn’t designed for that kind of stress.
Thanks for the insights, everyone! After reading your responses, I did some more research. Performance injectors are expensive!
Sorrell said:
Thanks for the insights, everyone! After reading your responses, I did some more research. Performance injectors are expensive!
Remember, when people talk about injectors, they’re often referring to an EJ platform, not the FA20DIT.