It's going to be a gas. (Energy).

Cleaner, cheaper fuel for cars, taxis and buses -- in the form of compressed natural gas (CNG) -- is coming into play in some of the most polluted capital cities in Latin America. And for good reason: besides costing half as much as gasoline, CNG is free from sulfur, lead and other pollutants. Rising to the occasion in smog-choked Santiago, Chilean CNG distributor Metrogas is building its fifth natural gas station. At the same time, the city has banned the use of leaded gas, and state oil company Enap has stopped producing leaded fuel. Meanwhile, Peruvian …