Mr Kite, I use them that exact way, Trip A for individual days or sections of trips for optimization and Trip B for each tank.

After filling up our 4th tank in PA with non RFG/Ethanol gas on Sunday my wife is kicking butt on gas mileage with a displayed average over 55 mpg. Our highest calculated mileage was on our 3rd tank of 48.5 mpg, so she is over 7.5 mpg higher. I am not ready to declare it all due to the gas yet, as the average temperature has been lower so she has used the A/C less and she corrected a driving deficiency part way through the 3rd tank. The car is also still breaking in. It is interesting though as others locally have reported a 5-10mpg difference from RFG/Ethanol gas to normal gas.