Are LPG and natural gas cars better for the environment?
In principle, carbon emissions from LPG and natural gas are reduced due to their low carbon content and high octane level. Methane is the main constituent of natural gas, which is also an important greenhouse gas and so must be taken into account when assessing the impact on global warming. Taking both carbon dioxide and methane into account, as well as the fact that using LPG increases fuel consumption by around 30%, bi-fuel gas cars show an improvement of around 10-15% as compared to those using petrol, and are therefore comparable with diesel greenhouse gas emissions. Regulated emissions are reduced for LPG and natural cars compared to conventional fuels. Even compared to petrol, which itself is low in NOx, the best quality bi-fuel gas engines produce fewer NOx emissions and virtually eliminate emissions of particulates. For natural gas vehicles, the unburned hydrocarbons (such as methane) also contribute less to tropospheric-ozone formation than do the volatile organic compounds pr
