We have a choice at the petrol bowser in Australia. Ethanol is not mandatory but it is cheaper. Our Mazda 3 is able to take ethanol blends but until September last year I preferred the best and most expensive super fuel that was available. I was under the impression that the more expensive fuel was good for the car. We had a starting problem with the engine. Since February last year it sometimes took three turns of the ignition to get our 3 year old car to start and the mechanic could not find a problem. Then I filled up with E10. My car has not missed a beat since I started the vehicle at the servo.... Perhaps it was just coincidence but I prefer to think that maybe it was karma for doing the right thing for the environment.