joel I think its possible but!!!!!
not with a small turbo if you went to a t4 and had a thicker head gasket yes but you would be running lower boost.
the set up would cost more than the 10 cents a liter you would save unless you plan on keeping the car for a long time.
I think tuning a car to run on 95octane is very possible
but regular ulp would be a bigger ask as the ron drops to 89 or so some times
meggala