and sciences education in Detroit through the Detroit Public Schools Foundation. Deliveries to retail customers in the United States began in mid December 2010. Volt deliveries began in Canada in September 2011. The first deliveries of the Chevrolet Volt in Europe took place in November 2011. The European version of the Volt, the Opel Ampera, was released to retail customers in Europe in February 2012. Deliveries of the right-hand drive Vauxhall Ampera in the UK began in May 2012. The Holden Volt was released in Australia in December 2012. Specifications Drivetrain The 2011 Chevrolet Volt has a / 45 A·h ( usable) lithium-ion battery pack that can be charged by plugging the car into a 120–240 VAC residential electrical outlet using the provided SAE J1772-compliant charging cord. No external charging station is required. The Volt is propelled by an electric motor with a peak output of delivering of torque. Capacity of the battery pack was increased to ( usable) for 2013 models, which increased the all-electric range from . Other specifications remained the same. The battery pack capacity was increased to for 2015 models. This incremental upgrade is likely to reflect in an improvement in range over previous model years, but , the 2015 Volt has not been re-certified with the EPA. While driving, after the Volt battery has dropped to a predetermined threshold from full charge, a small naturally aspirated 1.4 L 4-cylinder gasoline fueled internal combustion engine (Opel's Family 0) with approximately , powers a 55 kW generator to extend the Volt's range. The vehicle also has a regenerative braking system. The electrical power from the generator is sent primarily to the electric motor, with the excess going to the batteries, depending on the state of charge (SOC) of the battery pack and the power demanded at the wheels. Prior to the 2016 model year, the Volt required premium gasoline of (R+M)/2 octane rating of 91 or higher because the higher octane permitted the 10.5:1 compression ratio engine to use more ignition timing advance to maximize fuel efficiency by 5 to 10% compared to regular gasoline. For users who drive mostly in electric mode, and to avoid maintenance problems caused by storing the same gasoline in the tank for months, the 2011 Volt has a sealed and pressurized fuel tank to avoid evaporation. As a result, the fuel filler must be depressurized before opening the tank. Also, the