SAN JOSE, California – The electrification of the automobile may well be inevitable and plug-in hybrids our best chance to save the planet, but if they're going to sell, automakers and advocates must figure out how to market them. That means learning what consumers want, convincing them of the technology's personal and societal benefits and, perhaps most importantly, making the cars sexy.

It's hard to deny the benefits plug-ins and EVs offer in terms of curbing greenhouse gas emissions and slaking our thirst for oil. But new vehicle technology is slow to catch on – after a decade on the road, hybrids remain less than 3 percent of the market. Plug-in advocates at the Plug-In 2008 conference say they've got to find a way to radically accelerate that penetration rate if cars with cords are to have any kind of impact.

They can start by telling people what a plug-in hybrid is.

Researchers at the UC-Davis Institute of Transportation Studies surveyed 2,373 people contemplating a new car and found just 20 percent knew anything about hybrids. Even fewer knew about plug-in hybrids, says Ken Kurani, who worked on the survey that will be released early next month. Plug-in advocates clearly need to launch an aggressive PR campaign, because people won't buy what they don't understand.

Automakers also must do some homework. Most of them are developing plug-in hybrids without really knowing how many people want them, how they'll use them and how they'll charge them - if they can charge them. "These (issues) need to be defined and understood if we're to make these vehicles a large-market reality," says Nancy Gioia, director of sustainable and hybrid technologies at Ford.

The UC survey offers some insight. Most respondents place greater importance on overall fuel economy than electric range. Fewer than 10 percent could plug in at work, but half have an electrical outlet within 25 feet of their driveway. Bump the distance up to 50 feet and the figure rises to about 65 percent. "The 35 percent who don't have a plug represents the size of the problem," Kirani says.

Cost is another issue. Hybrids typically cost about $5,000 more than similar conventional vehicles and the premium for plug-ins will be higher. General Motors hopes to offer the Chevrolet Volt for $35,000 to $40,000 – about twice the average price of a new car. Even converting a hybrid or conventional vehicle to a plug-in costs as much as $12,000. Early adopters and passionate environmentalists will gladly pay that much, but everyone else will balk unless they're absolutely sure of coming out ahead.

They will, of course. Driving a plug-in costs a cent or two per mile compared to 20 to 25 cents for gas. Even accounting for the "plug-in premium," consumers will save thousands of dollars over the life of the car if they choose one that plugs in, says Mark Duvall of the Electric Power Research Institute. Plus, he and others say, they'll be helping curb greenhouse gas emissions and our dependence on foreign oil. Kurani says all of those points must be the focus of a sweeping "social marketing campaign" to convince consumers plugs are as good for them as they are for the environment.

Tax breaks and other incentives will help, but don't expect consumer altruism to move a lot of cars. Sky-high gas prices have people ditching their SUVs in favor of smaller cars, but emotion still plays a major role in what consumers buy, says Walter McManus, an economist at the University of Michigan Transportation Research Institute. People want a car that reflects who they are – or who they'd like others to think they are. In other words, image is at least as important as utility. Honda learned that lesson with the Civic Hybrid, which doesn't scream "I care about the environment!" like the Prius and so hasn't sold nearly as well.

Tesla Motors and Fisker Automotive get this. Their cars are sexy. They're cool. Yes, they're insanely expensive, but that too only adds to the appeal by making them exclusive. The fact that they're a more environmentally responsible choice is icing on the cake. The two start-ups know that, in McManus' words, "You have to address people's needs and wants and desires. You have to tell them, 'Look at all these great things you get and you're helping do this great thing.'"

Detroit and Japan can't – and shouldn't – make their EVs and plug-ins as expensive as Tesla and Fisker. But they and plug-in advocates would do well to crib from their marketing approach.

Photo of the Karma plug-in hybrid by Fisker Automotive.