I remember seeing several negative posts on this site re using HV Charge, but for a couple reasons decided to start using it myself: 1. Gas is much cheaper than electricity here at this time, and 2. I'll likely be selling my house in Spring and I don't want it to look like my solar panels are way undersized for the house. They're fine for the house alone but the PHEV is putting me well into the negative. Since the beginning of summer I have been getting between 49 and 50 mpg on every tank after subtracting off EV usage. I do like to use EV for local short trips and want to continue doing that. For a test I filled the tank while I had 10 miles of EV range left. I used HV Charge several times, both on highway and around town, so that when I refilled with gas I was at 10 miles EV again. And what gas mileage did I average for the 100% gas fueled travel? 49 mpg. It looks like HV Charge has excellent efficiency. So I think I am done charging this car until I sell my house.