IT's cheaper, safe and more easily available. No wonder more and more taxis and autorickshaws are opting for Liquefied Petroleum Gas (LPG) as against Compressed Natural Gas (CNG). Clear proof of this
Links:
[1] http://admin.indiaenvironmentportal.org.in/news/more-drivers-choose-lpg-over-cng
[2] http://admin.indiaenvironmentportal.org.in/category/newspaper/indian-express-mumbai
[3] http://admin.indiaenvironmentportal.org.in/category/thesaurus/vehicular-pollution