Chris Arcus, director of electrical engineering for Saba Motors, a team competing for the Auto X-Prize with a small electric roadster, thinks electric and plug-in cars from the major automakers will not be successful because they are too heavy. He says making a vehicle lighter (Saba’s Carbon-Zero Roadster weighs less than 2,000 pounds) will allow a car to go farther on a charge, alleviating consumers’ concerns about running out of power during while driving, or range anxiety. A smaller, lighter car means a smaller battery pack, resulting in shortened recharge times. Manufacturers like Saba believe the automakers start from the wrong premise by building their cars out of steel stamped in giant factories that require thousands of units to break even.

Automakers such as GM and Toyota counter that to make cars reliable enough to honor the long warranties that consumers expect, they have to use proven, existing processes. And they say that using lighter weight materials would drive up costs, adding to the already onerous costs premium electric cars face because of their expensive batteries.

Even GM and Toyota don’t agree on how promising plug-in technology is and how much testing infrastructure it requires.

In its press conferences at the show, GM has been touting the Volt as eliminating consumers’ range anxiety in electric cars. It can drive as far as you want once it’s 40-mile electric range is depleted, because its gasoline engine will power the onboard generator.

In an interview at the show, Bill Reinert, Toyota’s manager of advanced technology planning, said he expects that plug-in hybrids will encounter range anxiety issues. Consumers who shell out extra money for plug-ins will charge their cars at every opportunity, to ensure they’re never left without a full charge. This need will require massive numbers of public recharging stations.

But plug-in hybrids were conceived as an elegant bridge to more efficient electric or alternative fuel cars, because they didn’t require additional infrastructure before they could be rolled out to save billions of gallons of petroleum.

Now automakers on both ends of the spectrum, from Toyota and more conservative automakers to the startups, insist that they do need more infrastructure. And the automakers have no direct control over whether that infrastructure ever gets built. All automakers can do at this point is design and build the cars to work with existing plugs.

GM says that’s what it is doing with the Volt. Better than that, it says, these early plug-in hybrids will provide a customer base to pay for the installation of public charging stations that will eventually benefit other electric cars.

What do you think? Would you be worried about range anxiety with an electric car? What about with a plug in hybrid that could drive any additional distance on gasoline? Should small and large automakers wait for utilities to build public charging stations (and figure out how they’ll bill you for them)? Or should automakers go ahead and build plug in hybrids today and not wait for more public infrastructure to be built? Let us know in the comments below.