I have been keeping detailed stats since I purchased the car in Dec 2017. I had an '15 Accord I was leasing that I was using on trips and just used the Clarity around town until I turned in the Accord in Mar 2018. Now that I've been taking the Clarity on trips and actually using the gas engine now, I felt it was time to do a comparison between driving the vehicle in Normal mode (i.e. using up the battery and then auto HV) vs strategic use of HV mode (using only on sustained highway drives that are beyond my electric range). So far my results indicate that it is more efficient to strategically use HV mode vs driving the car in Normal mode. In April 2018, I went on 2 trips the first half of the month and just let the car select the propulsion (Normal mode). During the second half of the month I went on another 2 trips that were to different places but the mileage and driving conditions were nearly identical and good enough to do a comparison. This time I strategically used HV mode on the highway. From the picture, for the first half of the month, the vehicle attained a 57.9 mpg-e rating using Normal mode. For the second half of the month, the vehicle attained a 56.4 mpg-e rating strategically using HV mode. Yes this is lower, but to compare apples to apples we have to mix the same amount of EV driving to the second half of the month that I did during the first half. Once you hypothetically equalize the EV driving (i.e. same amount of Electricity used) to make an apples to apples comparison, the vehicle attains a 63.7 mpg-e rating. So far, the stats support using the propulsion sources advantageously.