A few months after we purchased our LEAF, I realized that our other vehicles typically just sit around, so we started filling two of them with ethanol-free gasoline only. I felt that pure gasoline would be less corrosive to the rubber parts of the engine and it would also likely absorb less water. I typically find I can purchase the ethanol-free fuel for only 3 to 5% more than "regular" gasoline. I suspected this would result in better fuel economy, thus eliminating any additional cost.
At this point, I have to conclude that the new plan is working out well for us. I recently achieved a record-high highway efficiency with our 2003 HCH of 56.0 MPG. I do not think I have previously ever exceeded 52 MPG in the entire life of the car. While a big part of this achievement was likely due to the hypermiling that I did on the trip, I credit pure gasoline as part of the reason for the result. Note that this was achieved with a 500-foot elevation rise on a highway with a posted speed limit of mostly 70 MPH with rain pouring down for about 1/3 of the drive in an 11.5 YO hybrid with 91,000 miles and a BMS which was reprogrammed in 2011 to reduce the SOC range used by the car.
So I'm interested in hearing others' experiences with ethanol-free gasoline in your ICEs and hybrids. Do you use it? How much extra does it cost? Do you think you get better fuel mileage? If so, how much better?
Also, does anyone have any links to good data on the performance of ethanol-free gasoline versus "regular" gasoline?
Finally, if you are wondering where to purchase ethanol-free gasoline, here is a link to a site which can help you find one: pure-gas.org