Summer went by uneventfully. I continue to drive Monday - Friday gas free with bit of gas used on the weekends.
So far I've traveled 5930 miles, 4170 electric and 1760 on gas (70% electric). For the 1760 gas miles the Volt used 42.5 gallons of gas for an average of 41.4 MPG. My overall mileage is 139 MPG, factoring in the cost of electricity it's roughly 89 MPGe.
The bulk of gas used was for two long distance trips. One, in July, from CT to the Outer Banks of NC. That round trip was approx. 900 miles. The trip down averaged 44 MPG, the trip home 46 MPG. Those numbers include the 40 miles or so of electric miles at the beginning of each trip. While in NC the Volt charged with the standard 120V charger using an outside outlet at the house we rented. All miles driven while there were electric. We had no issues on that trip. The Volt ran great and the seats proved comfortable for the 12 hour ride.
The second trip was to Cape Cod, we averaged 47 MPG on that trip including the 25 electric miles at the start. For this trip we drove to the Cape in MOUNTAIN mode, which essentially allows you to bank some miles. Once at the Cape, I took it out of MOUNTAIN mode and we had 15 miles of electricity available for driving around town. We parked in a public lot over the weekend with no chance to recharge.
There was one minor issue that cropped up. At certain highway speeds there was an inter-mitten knocking noise on the passenger side, I found it was the plastic wheel well liner that was slightly loose and knocking against the metal wheel well. I jury-rigged a fix and the dealer corrected it at the 5000 mile service which was basically a tire rotation. Other than that, no issues to support.
With no long distance trips on the horizon I'm sure the average mileage will get back up to where it was prior to the summer. Overall, love the Volt.