E10 or premium?

[buddy92]

I know this question has been done a million times, but I want to see if there's any solid evidence.

I always use premium ( they are all around 1.65 out here) and was wondering if there's any solid evidence saying that it is bad for my FG XR6 N/A? Giving the normal fuel is as low as 1.40 out here now it's a huge difference in price, but would it effect the car?