GM unveils the Obama limo

This car looks like an ordinary Cadillac DTS-based limousine, a standard passenger car that's a bit longer than usual. Front-wheel-drive, 275-horsepower V8.

It's not.

While most details about the presidential limousine that President-elect Barack Obama will be inaugurating Jan. 20 remain top secret, every indication is that it only looks like a Cadillac.

This built-to-spec vehicle is more of a rolling fortress, presumably equipped not only with the expected limousine amenities but also with bomb-proof windows, doors, and everything else.

The mass-produced civilian-duty Cadillac DTS can't handle all that weight, so experts have speculated the conventional body of the limousine is sitting on the same chassis as a one of General Motors's commercial trucks and using one of those trucks' massive engines. 

There's also no word on the gas mileage, but fuel economy does not seem to have been as much a priority as safety in designing the car. One thing is certain: "Cadillac 1" will be more economical than the other famous presidential transportation.

General Motors released the first official photos of the new limousine today, though unauthorized photographs had already been circulating online. 

You can also see a speculative cut-away rendering of the new limousine illustrating possible safety features beyond airbags.

GM also supplied two Cadillac limousines to George W. Bush and one to Bill Clinton, as well as various past presidents over the years.