Washington, Jan. 21 : Change has come not only to the White House, but also to the official presidential limousine.

On the day he was sworn in as the 44th president of the United States, Barack Obama shuttled around Washington in a virtually impenetrable armored Cadillac, which had doors at least five inches thick, reports the New York Daily News.

Obama''''s official car is a hybrid of a different sort. It has variously been described as part car, part truck and part tank.

"Although many of the vehicle''''s security enhancements cannot be discussed, it is safe to say that this car''''s security and coded communications systems make it the most technologically advanced protection vehicle in the world," said Secret Service spokesperson Nicholas Trotta in a news release.

President George W. Bush also cruised around the capital in a Cadillac - a 2006 DTS. Obama''''s is the first presidential car not to have a specific model name.

The new limo has bigger windows and better visibility than the Bush vehicle, but is about the same size, according to a GM spokesman. The limo is covered with heavy armor and has bulletproof glass, a sealed interior to block chemical attacks and state-of-the-art electronics.

It is a tradition for the Secret Service to debut new wheels for the nation''''s leader as the President-elect is chauffeured from the White House to the swearing-in ceremony and then down Pennsylvania Avenue for the inaugural parade.

This Cadillac was created specifically for the president and is "not a direct extension of any single model," said GM spokeswoman Joanne K. Krell.

"The presidential vehicle is built to precise and special specifications, undergoes extreme testing and development, and also incorporates many of the top aspects of Cadillac''''s ''''regular'''' cars - such as signature design, hand-cut-and-sewn interiors, etc.," Krell told CNN. (ANI)