Opel Astra is working on Compressed Natural Gas (CNG) which emit low levels of toxics and ozone forming hydrocarbons. But CNG fuel must be stored under pressure in heavy tanks and the cost of accommodating these tanks must be considered. A CNG vehicle stores gaseous fuel at a pressure of 2,400 to 3,600 psi.There are significant tradeoffs for CNG vehicles among emissions, vehicle power, efficiency and range. Engines fueled with NG in heavy duty vehicles offer more quiet operation than equivalent diesel engines making them more attractive for use in urban areas. Several vehicles are available today such as the Honda Civic CGX and the Ford Crown Victoria that operates on compressed natural gas.
Opel Astra is epuipped with start- stop-system achieved a CO2 emission of 90g/km and the 3 litres engine has an output power of 71 kW/97 hp moreover 35kw power is added additional by the electric motor. In currently opel offers Zafira CNG Turbo with an output power of 150 hp and emission of CO2 is 144g/km.