"What is 230?"

Perhaps you've seen the mysterious (and maddening) advertising blitz popping up on cable TV, elevator-TV screens and the internet this week. It features a smiling and winking electrical outlet that end up being the zero in the number 230, which itself appears above the numbers "8-11."

Some virtual detective work by Advertising Age -- and rounds of phone calls -- reveal the marketer behind the effort is General Motors Co. But neither the company nor its agencies would say exactly what the campaign is for.

"I'm glad it's getting out there," but no one wants to talk about it until next Tuesday, said Mike Rosen, president of GM agency Starcom, New York, who then declined to offer further comment.

A Chevrolet spokesman said he had no information on the 230 site and whether it was linked to the Chevrolet Volt, GM's upcoming electric car. He added that GM has scheduled a press conference for Aug. 11, but he cautioned it is not necessarily related to the 230 teaser site. He declined to make further comment.

The most frequent guess pins the campaign to the plug-in Volt, which will likely get its juice from the 230-volt outlets used to run heavier appliances such as air conditioners and washing machines. (UPDATE: Another guess being made by commenters and now being backed up by industry insiders is that the 230 refers to the miles per gallon the Volt will get. Though we'd love to see that math!)

Either way, why run a teaser campaign for a car that doesn't go on sale until next year -- and one that's been known about for some time? After all, the marketer has been beating the drum for the car for more than a year.

Another contender is a just-announced Buick cross-over SUV plug-in hybrid. According to auto blog GM-volt.com, the vehicle will be launched in 2011 "and is expected to be the first commercially available plug-in hybrid SUV produced by a major automaker."

Other guesses floated on the web included a prototype for a 230-mpg car (seen in this CNN video clip from last year), something to do with Apple, or the conversion of the entire U.S. electrical grid from 120 volts to 230.

Despite the curiosity in some quarters, though, the mystery and frustration haven't exactly spread like wildfire. There is a whatis230.com site, a Flickr photostream, a blog, a YouTube channel and a Facebook group -- none of which seem to be gaining the sort of traction that would make such a viral effort a true pop-culture phenomenon. (Though it does seem to be flirting with a backlash.)

Indeed, the Facebook group was one of the biggest clues. Meghan Winger, a staffer of Chicago agency All Terrain, is the creator of the What Is 230 group. She also posted a teaser about the campaign to the "What is 230?" YouTube channel. All Terrain, which among other things is touted as a "social-media expert" on its website, lists Chevrolet at the top of its client roster. Others who oversee the Facebook page include: All Terrain marketing coordinator Noor Aweidah, who today Tweeted that "should know what 230 means"; Jeff Schwartz, who lists GM and Chevy Riders as his favorite products on his Facebook page; and Ashley Berlin, a media planner and buyer for Starcom Mediavest Group, a GM agency.

So yes, "What is 230?" is an ad campaign. It's for a GM product. But that's all anyone's saying at this point.

----update________

DETROIT (AdAge.com) -- Fritz Henderson, CEO of General Motors Co., admitted this morning in a live webcast that the automaker was indeed behind the mysterious, unbranded website whatis230.com, as first reported here last week.

General Motors Co. CEO Fritz Henderson at a live webcast this morning.

Photo Credit: GM

The number's significance, Mr. Henderson said, is that the Chevrolet Volt plug-in car due later this year is expected to get city fuel economy of at least 230 miles per gallon, or 25 kilowatt hours per 100 miles. That performance, based on fuel-economy methodology being developed for plug-in cars by the U.S. Environmental Protection Agency, would make the Volt the first mass-produced vehicle to achieve triple-digit fuel economy. Mr. Henderson said GM expects the Volt could be totally recharged for about 40 cents.

GM expects to produce roughly 60,000 of first-generation Volts, which are scheduled to go on sale in late 2010 as 2011 models.

So why run a blind teaser campaign? Mr. Henderson said that in order to win a new generation of buyers, "we need to relate to people between 16 and 30. They communicate differently and we need to make sure we plug into that. It's going to change advertising and it's going to change marketing and, over time, how we sell cars."

Campbell-Ewald, Warren, Mich., created the 230 site. Chevrolet's longtime agency of record subcontracted with All Terrain, Chicago, which activated street teams to distribute hats and T-shirts with whatis230.com in several major cities.

GM also is ready to start its car-selling pilot on eBay, which Mr. Henderson announced a month ago in a webcast the day the new GM exited from reorganization under Chapter 11 bankruptcy. Mr. Henderson said the program extends the showroom into Americans' living rooms and "makes the customer the center of our universe."

He also vowed to put more of GM's communications resources to its four core vehicle brands -- Buick, Cadillac, Chevrolet and GMC -- instead of the GM brand, because "we don't go to market as GM." This move is likely to severely slash the amount of work handled by McCann Erickson, Birmingham, Mich., which has GM's corporate account.

The GM chief's webcast today followed a session yesterday with invited consumers, many of whom he described as past GM owners and "thoughtful critics" of the automaker on its blog at fastlane.gmblogs.com. GM today launched a microsite called The Lab, which will feature future projects and will be another place for consumers to share their reactions. The marketer said visitors who provide detailed demographic information may be invited to participate at a deeper level in future sessions.

In other announcements today, Mr. Henderson said:

• GM plans to launch 25 new models arriving between now and 2011.
• Chevrolet will have 10 new models, including the new Cruze small car next year.
• Cadillac will have five new models, including an entry luxury-sport sedan, smaller than the CTS, to compete in that growing segment.
• Buick and GMC are adding 10 new entries, including a Buick plug-in hybrid compact crossover, in 2011