Some of the Detroit automakers have started their endeavor of producing plug-in hybrids to contribute to a cleaner and greener environment. With the increasing demand for fuel-efficient cars, automakers are given no wider leeway but to build more hybrids and flex-fuel vehicles.

The Congress is yet to pass a more stringent fuel mandate that would significantly increase mileage. The automakers, meanwhile, do a lot of lobbying efforts to circumvent it. In the previous weeks, some efforts of the auto industry, aimed at stopping the passage of stringent mandates, have failed. This is why automakers are more rigorous and accurate now in their strategies.

Major obstacles are persistent. "Spiteful" fuel legislations, rising gasoline prices, and costly plug-ins production costs are deemed major obstacles in the industry.

As a fact, if more than half of the motorists in the United States switched to plug-in hybrids, the country's greenhouse gas emissions would decrease by the middle of this century, according to a July 19 study from the Electric Power Research Institute and the Natural Resources Defense Council.

The companies' study found that if plug-ins accounted for 60 percent or more of new vehicles sold, greenhouse gas emissions could be reduced by a third or about 450 million metric tons annually by the year 2050. Additionally, the researchers factored in a period of time for plug-in sales to ramp up. But the query is: Could the automakers handle such big switch?

Chevrolet, Saturn and Toyota are among the automakers experimenting with plug-in hybrids.

The General Motors Corp. is on top of the list of automakers engaged in plug-in hybrids. Saturn might well be the first one to sell a plug-in. The company announced at the 2006 year's Los Angeles Auto Show that it is developing a plug-in version of the Vue Hybrid that it hopes to start selling in 2009. The Saturn fuel saver could be enhanced to serve the end.

Chevrolet, which has put a lot of time and money into its Volt concept car, plans to have a plug-in ready to sell to consumers by 2012. The company makes the enticing promise that people who drive less than 40 miles on a daily basis will never have to fill up, and those who drive over that will average 150 mpg.

Another famous name in the production of such unique hybrid is the Toyota Motor Corp. At present, Toyota is developing the Plug-in HV, which made headlines this week when the Japanese government gave approval for the vehicle to run on public roads for tests.

Plug-ins do have some big problems to overcome: the added cost, weight and cargo space of the batteries they must house; the limited range of the batteries when charged; and the impact on the power grid from millions of people plugging in their cars, reported MSNBC.

The report continued: "States like California and big cities like New York know a thing or two about blackouts due to high demand for electricity in summer months. Residents there are also familiar with the rate hikes that accompany the local electric companies' struggle to improve their infrastructure."

Mike Omotoso, a senior manager at the market research firm J.D. Power and Associates, said that he thinks widespread electricity demand for cars has the potential to be an issue. "We haven't looked at that sort of extreme scenario in terms of that level of volume for plug-ins, but the increased demand would possibly put a strain on the grid, especially in places like California that are already under strain some times of the year, like in peak summer periods with everyone using their air-conditioning," he said.