International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

Today, there is a significant interest in alternative energy sources for vehicles, as a result of continuous concern for the environmental impact and for consumption of the primary energy sources, which are limited. Diesel engines present particularly significant emission like nitrogen oxides, particulate matter, hydrocarbons and black smoke. This paper present a literature review on some alternative fuels for diesel engines, as pure plant oil, biodiesel and compressed natural gas, and their impact on diesel engine emissions.