General Motors stated that a fully charge battery of Lithium-Ion construction are getting 40 miles per charge in road tests. This is a big hurdle because battery technology is the biggest hurdle that PHEV and PEV cars face as they try to run off of a small gasoline engine that fuels a battery powered drive train.
The next step for GM is smoothly integrating a battery engine with the gas powered recharger. This is a much different process from the typical Hybrid vehicle that is currently on the market which uses a gasoline engine and battery engine in combination.
GM has designed the Chevy Volt to average around 40 miles a day using only electricity from the grid with a number of range extenders using gasoline, e85 ethanol and in the future hydrogen. The goal for GM is to have the Volt get a range of approximately 640 miles using the battery and fuel of choice.
PHEV Vehicles are a great step in the right direction but ultimately our future lies in vehicles that produce zero emissions, cost the same as vehicles do now, and have all the amenities that drivers these days expect. When a vehicle like that is released, it will provide that alternative that all of America is looking for. Until that time we should focus on using the green alternatives that are available to us now: public transportation, walking & bicycling, and vehicles that get over 35 mpg.