They (the German government) virtually forced the sale of E10 (10 % Ethanol) fuel, and, like a muppet, I tried it - but only once. I tanked up 40l in my POV (a Hyundai Getz) and drove from Franfurt to Duesseldorf to visit my mother. 225km each way. Compared to other times, driving in the same manner (maybe not according to my navigation system!), I used up to 20% more fuel. So no savings, which was the government's "white lie". I also noticed problems in going up steep hills.
Not wishing to damaged my engine, I've gone back to destroying the planet!