2006 Detroit Auto Show, overcoming internal opposition that recalled losing a billion dollars in the 1990s over the EV1 electric vehicle program. Lutz's initial idea was to develop an all-electric car, but Jon Lauckner, General Motors Vice President for global program management, quickly sketched out the powertrain layout, estimated the vehicle weight and battery requirements, convinced Lutz that to avoid an expensive battery, range anxiety concerns, and lack of public charging infrastructure, they could use a smaller battery pack with a small combustion engine driving a generator acting as a backup to extend the range, but without a mechanical connection between the gasoline engine and the drive wheels, so it would be a pure electrically driven vehicle without many of the limitations General Motors learned from the EV1 experience. Most of the Volt initial design parameters defined for the development of the concept car, then referred as the "iCar" in homage to the iPod, were kept throughout the process up to the final production version. A key design parameter was a target of for the all-electric range, selected to keep the battery size small and lower costs, and mainly because research showed that 78% of daily commuters in the U.S. travel 40 miles or less. This target range lets drivers make most travel electrically driven, with the assumption that charging takes place at home overnight. This requirement translated to using a lithium-ion battery pack with an energy storage capacity of 16 considering that the battery would be used until the state of charge (SoC) of the battery reached 30%. This limit to the SOC was necessary in order to maintain operational performance under a wide range of environments, and to minimize the battery degradation to allow at least a ten-year life span. The initial target range for the gasoline engine/generator was set between and the vehicle had to be family size for four or five passengers. Another key design decision was to develop the concept car based on a new family of common powertrain components for electric propulsion, which initially was called the E-Flex Systems, "E" stands for electric drive and "Flex" for the different sources of electricity, but later was renamed Voltec drive system. The E-Flex or Voltec powertrain is an attempt to standardize many components of possible future electrically propelled vehicles, and to allow multiple interchangeable electricity-generating systems. The E-Flex powertrain has the potential to adapt the vehicles