GM is looking for a big PR push with the Chevy Volt, and their announcement that the new Chevy Volt will get 230 miles per gallon will certainly grab some positive attention for the beleaguered company.

General Motors Co. said today the Chevrolet Volt, its extended-range electric vehicle due out in November 2010, will get an estimated city fuel economy of 230 mpg, or 25 kilowatt hours per 100 miles.

GM will unveil 25 new models between now and the end of 2011, president and CEO Fritz Henderson said during an hour-long webcast this morning.

“When the Chevrolet Volt extended-range electric vehicle rolls off the assembly line late next year, it will be the first mass-production automobile to achieve triple-digit fuel economy, with an expected 230 mpg in the city, or 25 kilowatt hours per 100 miles,” GM said.

The Environmental Protection Agency declined to confirm the figure, which was based on a draft testing procedure. GM said the calculation is based on more than one vehicle electrical charge, since the average driver travels far less than 100 miles in a single day.

“EPA has not tested a Chevy Volt and therefore cannot confirm the fuel economy values claimed by GM,” said EPA spokeswoman Cathy Milbourn.

“EPA does applaud GM’s commitment to designing and building the car of the future: an American-made car that will save families money, significantly reduce our dependence on foreign oil and create good-paying American jobs.”

In recent days, GM had launched a “viral” marketing campaign featuring a green background and a “230″ logo — with a plug in the place of the 0 — to build interest in today’s announcement. Many auto bloggers correctly guessed that the figure was connected to the Volt’s city fuel economy rating.

The viral campaign is another good idea, and it looks like we really might have a “new GM.”

That said, the important story here is we’re seeing a plug-in hybrid that will potentially be a game-changer in the auto business. For a country that imports a ton of foreign oil, it’s refreshing to see real progress on electric vehicles.

Of course, not everyone is impressed, including Nissan.

But at least one competing automaker isn’t convinced. “Nissan Leaf = 367 mpg, no tailpipe, and no gas required. Oh yeah, and it’ll be affordable too,” the folks over at Nissan’s electric vehicle Twitter feed wrote today. About an hour later, they added this statement: “To clarify our previous tweet, the DOE formula estimates 367mpg for Nissan LEAF.”

That’s even more great news. It looks like there will be serious competition here from other automakers, so perhaps consumers will have real choices, and we can make real progress towards a goal of eliminating oil imports.

Wired.com’s Autotopia blog has a cool post of five auto-related terms that will be dying out soon along with five new terms that we’ll need to become familiar with. You’ll soon be forgetting terms like gas pedal, MPG, throttle, transmission and tachometer. Here’s one of the new ones:

Parallel vs. series hybrid – These terms have so far been relegated to the geeks, but as the industry progresses and hybrids of all stripes become more common, you’ll want to know the difference. They refer to how the gasoline engine and electric motor are configured. A parallel hybrid like the Toyota Prius uses a traditional transmission to couple the gasoline engine and electric motor to the wheels. Such vehicles use internal combustion and electricity to drive the wheels. A series hybrid like the Chevrolet Volt does away with the transmission because the engine drives a generator that takes over when the battery runs down. The electric motor is the only thing driving the wheels. Many see the series hybrid as the “true” hybrid configuration minimizing energy loss due to wasteful idle engine spinning friction.

Also, get ready to hear the following terms as well: Lithium-ion battery, continuous vs. peak power, kilowatt-hour vs. kilowatt and drive-by-wire.