Fuel 103 Congresses 59 Nuclear fuels 27 Fuel consumption 22 Synthetic fuels 22 Combustion 21 Power resources 20 Automobiles 19 Waste products as fuel 18 Gas as fuel 16 Liquid fuels 16 Refuse as fuel 16 Fuel systems 15 Motor fuels 15 Economic aspects 14 Environmental aspects 14 Coal 13 Reactor fuel reprocessing 13 Fossil fuels 12 Fuel trade 12 Alcohol as fuel 11 Motor vehicles 11 Prices 10 Standards 10 Biomass energy 9 Furnaces 9 Hydrogen as fuel 9 Nuclear fuel claddings 9 Analysis 8 Diesel motor 8