It wouldn't but the fuel system without injector and fuel pump upgrades can only handle e50 at the very most safely before start to lean out.... and, not replying to you here, but just to reiterate, we pretty much all know that e30 will max out the stock turbo but e50 offers the convenience of no math to simply mix half and half. On another thread, I also gave my personal observation of using 87 as the mixer is fine too, the difference between 87 and 91/93 is mainly some additional detergents and octane boosters, both unneeded when you already have more octane, more charge cooling AND more cleaning power that you'll ever need with so much ethanol. Some people will just want to use premium regardless, and I made a case why I think that's a waste on a stock turbo, but to each their own. I'm not gonna bash anyone for it, I was just making my case "scientifically" for discussion purposes for those who wish to engage.