I would like to further discuss the topic of ethanol free gas without it going further off topic. That being said I did want to respond to the posts quoted below.
I have had a lot of good results using ethanol free gas in multiple vehicles over the course of probably a decade. I don't mind paying slightly more for a fuel that provides better performance and fuel economy. Anecdotally I recall seeing information that suggests that ethanol free gas can contribute to a reduction in carbon buildup in gasoline direct injection engines. I will have to dig around to find it again.
The more Ethanol the better as it’s a good detergent for your engine. Keeps the combustion cycle a lot cleaner and reduces emissions. This also prevents carbon build up in the engine and EGR system , especially the tops of the intake valves since our engines are DI.
I would like to request citations from you to validate everything you have stated in the quote above about the notion that ethanol somehow prevents carbon buildup in direct injection engines.
The gas doesn’t pass over the intake valves in DI fuel systems. Top tier gasoline has detergents in it and is the recommended fuel for DI systems to keep the fuel system, primarily the high pressure injectors, clean. To prevent carbon build up in our 3.5L engines it will be required to have a periodic induction cleaning done. Honda will recommend this to you at some point if you take your vehicle to them for service. It is pretty expensive which is sad because it’s such an easy process to perform.
To clarify and make distinctions, there is NO way to prevent carbon buildup in direct injection engines. In the event that carbon buildup occurs to the point of severely impacting engine performance and/or operation, yes there are methods to deal with said buildup.
I would not concern yourself with it too much because it primarily affects TURBO gasoline direct injection engines (TGDI).