NEW DELHI (AP) - For millions of people in the developing world, Tata Motor's new $2,500 four-door sub-compact - the world's cheapest car - may yield a transportation revolution with as great an impact as Henry Ford's Model T, which rolled off an assembly line one century ago.

The potential impact of Tata's Nano has given environmentalists nightmares, with visions of the tiny cars clogging India's already-choked roads and collectively spewing millions of tons of carbon dioxide into the air.

Industry analysts, however, say the car may soon deliver to India and the rest of the developing world unprecedented mobility.

"It is a potentially gigantic development if it delivers what has been promised," said John Casesa, managing partner for the Casesa Shapiro Group, a New York-based auto industry financial advisory firm.

The basic model, expected to roll of assembly lines later this year, will sell for 100,000 rupees, or about $2,500, but analysts estimate customers could pay 20 percent to 30 percent more to cover taxes, delivery and other charges.

Company chairman Ratan Tata, who introduced the new car at India's main auto show, has long promised a $2,500 "People's Car" for India - a country of some 1.1 billion where only seven of every 1,000 people own a car. The company will not say how the price was kept so low on the basic version and will not say how much the luxury Nano will cost until it hits showrooms toward the end of this year. The company also refused to let reporters sit in the car, let alone drive it.

But the basic version is austere: there is no radio, passenger-side mirror, central locking or power steering and only one windshield wiper. Air conditioning that would spare motorists the brutal Indian summer is available only in deluxe models.

Analysts believe the Nano could transform the auto industry, forcing manufacturers to lower prices, and perhaps find cheaper ways to sell cars than in sprawling showrooms.

For now, the car will be sold only in India, but Tata said it hopes to export it to developing nations across Asia, Latin America and Africa in two or three years.

Tata initially plans to manufacture some 250,000 Nanos per year. That would be about a quarter of all cars sold in India last year.

The emergence of the Nano has fuelled a host of concerns.

With developing countries like India and China putting more and more cars on the roads, it has created a greater demand for fuel, contributing to sky-high global oil prices. India consumed nearly 120 million tons of petroleum products in 2006-2007, according to the Petroleum Ministry, up from 113 million tons the previous year.