At least once a month, I am disappointed to get into my Volt and find that I forgot to plug in the charging cable the day before. This morning I find an estimated 4 miles of electric range left. My roundtrip commute to work is 30miles but yesterday I had to run a few errands(typically EV range is 50miles). I decided to immediately switched to mountain mode to try to recharge the battery for the return trip. I arrive at work and switch to normal mode with 17miles of range showing. I don't quite remember the exact fuel used, but I think it was at least 0.5 gallons. I used the remaining range to get back home. My question is whether or not this actually saved any gas compared to driving the whole way in normal ranging extending EV mode. I assume more gas is used in mountain mode to charge up the battery.