“What I Learned Today” With Jeff Smith — Ethanol Isn’t The Bad Guy

Also note the effect of high portions of Eth on the distillation curve.
fuel-distillation-2007-png.png

However this phenomenon can also be seen in the RFG testing of MTBE fuels even without the Eth.
Details of that graph and the other I made using the data from Durbin, et al. here Video of boiling point of fuel (ACE Optimal Blend Study 2007, Durbin et al CRC-E67)