All kinds of green cars are eligible for tax breaks, but the 2011 Porsche Cayenne Hybrid could be one of the most expensive vehicles ever to get the IRS' nod of approval.

The Cayenne S Hybrid earns its buyers up to $1,800 in federal tax credits, the automaker says, making it the first Porsche ever to qualify for the deduction.

The new Cayenne S Hybrid is also Porsche's first gas-electric vehicle, and according to the manufacturer, it's capable of a 0-60 mph time of 6.1 seconds, and can reach a top speed of 150 mph.

The tax credit is good for vehicles purchased before December 31, 2010, and it applies to Hybrids already purchased this year--so long as it's the buyer's first time using the deduction.

Each automaker is allocated a specific number of vehicles that can qualify for this tax incentive, which aims to put more people in more efficient vehicles. Some automakers and model lines have run out of eligibility, as is the case with the Toyota Prius. The just-emerging tax situation for all Americans in 2011 is still unclear on whether these credits will be extended, or if they will expire.

The Cayenne S Hybrid is priced from $67,700 before destination charges, and before the tax credit is applied. It's rated at 20/24 mpg by the EPA, even with a stout 380 horsepower on tap from its supercharged, hybridized V-6.

For more on specifications, pricing, photos, and related news, click over to TheCarConnection's 2011 Porsche Cayenne page.