Mexico City, Mexico - The Mexico City government has unveiled a fleet of eight diesel-electric hybrid buses that will be the first to hit the roads in Latin America.

The new buses have a system that combines an internal combustion engine and an electric motor and are to be used on the Mexico City Metrobus system’s new Line 4, which will link downtown with the international airport, the government said in a statement.

Metrobus director Guillermo Calderon presented the buses this month at Mexico City’s Expo Foro 2012, an event in which manufacturers and distributors of buses and commercial vehicles showcased their latest innovations and exchanged information and experiences.

The hybrid propulsion system makes the buses more efficient, enabling them to use 30% less fuel and therefore emit fewer pollutants, the statement said.

Compared with buses currently in operation, these vehicles will emit 50% less carbon dioxide, 60% less nitrogen oxide and 80% less particulate matter, it added.

Line 4’s 46 non-hybrid buses, which have been awarded the highest environmental certifications on the market, will run on UBA (Ultra-Low-Sulfur) diesel.

The municipal government said that the use of these more environmentally friendly public-transportation vehicles will reduce the emissions of the pollutants that damage historical buildings and monuments.

The launch of Metrobus’ Line 4 also will lead to a reduction in greenhouse gas emissions of 110,000 tons annually, according to the statement.

In another initiative to improve air quality in Mexico City, a highly polluted metropolis that is home to some 20 million people, the emblematic Volkswagen “Bug” taxis that have transported millions of people in the capital for decades will be taken off the roads later this year.

The popular Bugs, known as “vochos” in Mexico, “will be taken out of service for being highly polluting and because their lifespan has run out,” Mexico City’s taxi services director, Victor Ramirez, reported earlier this month.

He said over the past few years the iconic taxes have gradually been replaced by more modern vehicles and now just 3,500 VW Beetles need to be retired.