Indonesia promotes biodiesel consumption through a blending mandate and a subsidy program. The current required biodiesel blend level in transport fuels is 20%, set to increase to 30% in 2020. The mid-level blends required to meet the mandate may raise concerns of combability in vehicles. Biodiesel reduces fuel economy and can degrade some vehicle components and materials, as well as affecting vehicle emissions. Vehicles specially designed for higher biodiesel blends are available, but most diesel vehicles are not designed for the use of these blends. Previous studies on biodiesel impacts on vehicles have mostly focused on vehicles and fuels in Europe and the United States. Indonesia’s case may be different because it mostly uses palm oil to produce biodiesel, has a warm climate, has a vehicle fleet with older technology, and tends to have lower fuel quality and higher fuel sulfur content than in Europe and the United States. This working paper reviews the effects of biodiesel on vehicles specifically in the Indonesian context. It does not address other renewable diesel substitutes such as hydrotreated vegetable oil.
This paper first reviews the effects of biodiesel on emissions of nitrogen oxides, carbon monoxide, hydrocarbons, and particulate matter in conventional vehicles. It compares the effects of using palm biodiesel and other biodiesel feedstocks, such as soy and rapeseed oils. The paper then reviews the effects of biodiesel on vehicle materials, including components of the fuel supply, engine, and exhaust system. These effects include corrosion and wear of metallic components, degradation of elastomers, and deposit formation in filters and fuel injectors. The implications of the impacts of biodiesel on vehicle emissions and materials are discussed in the context of Indonesia specifically.