# General knowledge

## What is CNG

CNGCNG stands For Compressed natural gas , which can be used used  as an alternative fuel in internal combustion engines , CNG is a mixture or hydrocarbon gases and Vapours in which methane is the main Constituent . This is compressed to a very high pressure for use in automobile . Octane rating of CNG is about 120  , hence it is a far superior fuel as compared to petrol . further engine running on CNG are environmental friendly , noiseless and require almost no maintenance .
CNG as an alternative fuel for ic engine has for better future as it pollution free . it does not contain any harmful substance like nitrogen , lead , sulphur , thus there are no NOx and So2 emission , further CNG burn completely and does not produce CO and any odour nuisance .

Key point to remember

1. CNG also know as - Compressed natural gas .
2. CNG is made by compressing natural gas  ( specially composed of methane ) .
3. Octane rating of CNG about 120  .
4. Chemical formula of methane is - CH4 .
5. Compressed natural gas lighter than air .
6. CNG mainly used in gasoline , diesel fuel  .