We appear to be getting more than we bargained for with LPG vehicles. A study conducted by Clean Energy Nepal (CEN) with the help of the Valley Traffic Police indicates that gas-run vehicles are not as clean as they are thought to be. CEN had tested 35 LPG-powered vehicles, both three- and four-wheelers and the results were telling: 55 percent failed emission standards set by the Ministry of Population and Environment. An LPG-operated three-wheeler is allowed to emit at most three percent carbon monoxide (CO) by volume and 7,800ppm (parts per million) hydrocarbons (HC). Four-wheelers may emit up to three percent CO and 4,000ppm HC. Tailpipe emission tests found as much as 8.16 percent CO by volume, and 4,000ppm HC emitted.
This is bad enough, but what makes it worse is that the government provides import subsidies to these vehicles (99 percent on custom duty and 100 percent on VAT) on the assumption that they're clean.