"New York will now no longer have taxis that were simply bought off the rack," Bloomberg said. "We worked with Nissan to come up with a taxi that meets our city's very peculiar needs, with a purchase price that we think is great for taxi owners and incidentally for fuel efficiency and operating costs that are great for drivers."

Nissan beat out Ford and the Turkish company Karsan in the Taxi of Tomorrow competition, which was launched in 2007 and solicited online comments from about 26,000 New Yorkers. Nissan's winning model, the NV 200, will be roomier than the Crown Victorias currently comprising the majority of the city's taxi fleet and boasts features like passenger side airbags, a retractable sun roof and stations for charging cellphones.

It will also get an estimated 25 miles to the gallon compared to the 12-13 the Crown Victorias get, leading Bloomberg to lauded Nissan's "significant commitment to testing and adopting alternative fuel technology." Bloomberg added that Nissan will be able to mass produce electrically powered models by 2017.

The contract represents a significant windfall for Nissan. There are currently 13,237 taxis in New York City, and Taxi and Limousine Commissioner David Yassky estimated that replacing them with Nissans will cost about $1 billion over the length of the contract.

"It's a win win opportunity to aggregate the city market power and give automakers the opportunity to link its brand to the powerful New York taxi brand," Yasskey said.

Prior to the announcement this morning, Brooklyn Borough President Marty Markowitz, Public Advocate Bill de Blasio and Assemblyman Michah Kellner sent a letter to Comptroller John Liu charging that the competition was tainted by a conflict of interest. The letter suggested that a leaked report by the firm Ricardo, Inc. -- a former client of both Ford and Nissan -- was critical of Karsan and thus preemptively compromised the firm's chances.

"Recent events have led us to believe that the Taxi and Limousine Comission and a consultant involved in the project, Ricardo, Inc. may have been in violation of conflict of interest provisions in the 'Taxi of Tomorrow' Request For Proposals," the letter said. "The purpose of this letter is share with you the facts and circumstances that have led us to this conclusion, and thereby ask that you investigate whether major violations of the RFP have occurred when reviewing the final bidder determinations for awarding the 'Taxi of Tomorrow' contract."

Bloomberg dismissed the allegation, saying Karsan was in denial over losing the contest.

"This is ridiculous that companies, when they lose, they want to rush to some elected officials to have them try and stop everything," Bloomberg said in response to a question about the letter. "I don't think I've ever seen a process that's run as well."

Karsan had also altered its earlier plans by proposing a plant in Brooklyn -- the Nissans will be manufactured in Mexico -- but Bloomberg called that plan infeasible.

"Unfortunately, since our time schedule calls for these taxis to be on the road in a couple years, it shows you the difficulty for overseas companies to really understand how New York works and how you do things in New York," Bloomberg said. "I do not think in two years we could site and build a new school, much less an industrial plant."

At one point Yassky reminisced about the iconic checkered taxicabs of his youth and said he hoped that the new cabs could generate the same type of affection. But Bloomberg later acknowledged that the minivan-shaped Nissan model moves more of a suburban sensibility more than its predecessors.

The mayor also confirmed that, between taking official vehicles and his own personal cars, he never hails a cab. That, he noted, will change.

"In 973 days I'll be back to taking taxis," Bloomberg said.