To change Americans' mood on diesel, Audi has turned to an actress who plays a bipolar character: Claire Danes.

The "Homeland" star, who plays a troubled C.I.A. agent in the Showtime series, will help launch Audi of America's new campaign around its TDI clean diesel-powered vehicles starting Sunday with a series of spots that will air on TV and online.

The new marketing effort was designed to promote Audi's return for a third year as the official automotive sponsor of the Television Academy and the Emmy Awards, on Sept. 22, while cleverly tapping into Danes' character on "Homeland" in a humorous way.

In the "Smart Performer" video, a "Sliding Doors" premise features Danes behind the wheel of an Audi A6 TDI as her life takes two very different paths, one calm and the other comedically manic. Jordan Vogt-Roberts ("The Kings of Summer"), who has helmed shorts for Funny or Die, directed the ad.

The short hypes Audi's TDI technology and how its cars deliver a combination of performance, fuel economy and luxury.

"The concept sounded like a hoot," Danes told Variety from the set of "Homeland," in North Carolina. "It was a charming conceit. I've been playing Carrie Mathison for quite some time now. As wonderful as that experience is, it's relentlessly intense and grueling and the stakes are high. It was nice to do something a little silly."

The shoot, which took place only two weeks ago, surrounded Danes with comedians who were encouraged to improve during the production -- another stretch for Danes who must normally stick to the "Homeland" scripts.

"It was just really loose," she said. "We improvised a lot, which is something we're not able to do on 'Homeland,' where each word is carefully selected and we have to make a petition to change anything. It was a nice gift to goof around and not be so reverent to the material and experiment with a different plane. It was a nice reprieve from the apocalypse and to be able to step out of the burning building for a second. I hadn't had a day like that in a long time."

Plus, there were puppies on set. "I got to play with many puppies, which was massively enticing," she said.

To land Danes, it also helped Audi that the actress was a fan of its cars.

"I really do like the car," Danes said. "I have always liked Audi cars. I think they're beautiful and luxurious without being pretentious."

Naturally, Showtime also benefits from the Audi ad, with "Homeland" getting some additional marketing support for its new season that starts airing Sept. 29.

Riffing on a role an actor plays isn't new for Audi. When "Star Trek Into Darkness" was released in May, Audi hired two other fans of the brand, Zachary Quinto and Leonard Nimoy, to appear in a spot that playfully references their roles as Spock in the TV show and films to promote Audi's vehicles.

SEE ALSO: How Audi Upstaged Mazda's 'Star Trek' Campaign

With Danes, Audi wanted to take a more tongue in cheek approach to promoting diesel, and "have a little fun with teh story," Angelo said. "If you make the alternative choice, funny and outrageous things can happen to you. Giving it that entertainment value helps Americans embrace the message to give diesel the consideration" when choosing their next car.

Audi cast Danes because it wanted someone who not only is familiar to TV audiences, but an actress "who is very sophisticated and rational but has such a powerful acting career that she could play with an exaggerated story" and get Audi's message across.

"We still have a substantial awareness challenge" for diesel in United States, admits Loren Angelo, director of marketing for Audi of America. "The awareness is simply not there. There's been a lot more discussion about electric mobility and hybrid solutions, but more and more brands are starting to talk about the benefits of diesel."

The first teaser of the "Smart Performer" video will debut Sept. 15, during NBC's "Sunday Night Football" game, with a full director's cut available on Audi's YouTube page that evening.

Audi will air additional teasers on other netowrks throughout the week with a new version of the short with Danes set to air during the Emmys telecast.