Related by context. Frequent words. (Click for all words.) 59 particulate emissions 58 carbon dioxide emission 58 particulate matter emissions 56 NOx emissions 56 nitrogen oxides NOx 56 nitrous oxides 55 CO2 emissions 55 pollutant emissions 55 NOx 54 particulate matter PM 54 carbon dioxide emissions 54 CO2 emission 53 nitrous oxide emissions 53 SO2 emissions 53 sulfur oxide 53 pollutants emitted 52 nitrogen oxide 52 sulfur dioxide SO2 52 greenhouse gases GHG 52 emmissions 52 nitrogen oxide emissions 52 nitrogen oxide NOx 52 exhaust emissions 52 Carbon dioxide emissions 52 GHG emission 52 C# emissions 51 particulate filters 51 emissions 50 CO ² 50 CO2 emitted 50 emission 50 exhaust emission 50 CO2 Emissions 49 CO2 49 VOC emissions 49 SF6 49 emit CO2 49 conventional internal combustion 48 diesel particulate filters 48 carbon emission 48 CO -2 48 carbon dioxide emitted 47 carbon emissions 47 Co2 47 nitrogen oxides 47 carbon dioxide CO2 emissions 47 greenhouse emission 47 reducing CO2 emissions 47 Emissions 47 greenhouse gas emission reductions 47 sulfur dioxide nitrogen oxides 47 sulfur dioxide nitrogen oxide 46 greenhouse gas emissions 46 greenhouse gases GHGs 46 SOx 46 carbon dioxide CO2 46 diesel particulate matter 46 CO2e 46 greenhouse emissions 46 smog forming emissions 46 sulfur fuels 45 reduce carbon emissions 45 carbon dioxide 45 GHGs 45 Selective Catalytic Reduction SCR 45 sulfur oxides 45 diesel particulate filter 45 #KW [001] 45 CO2 emitting 45 GHG emissions 44 desulphurisation 44 SO2 44 NOx reduction 44 sulfur dioxide emissions 44 Emission Control 44 preindustrial levels 44 tailpipe emissions 44 greenhouse gases emitted 44 greenhouse gasses 44 greenhouse gas GHG emissions 44 NO2 44 carbon emitted 44 particulate filter 44 gigajoules 43 co2 43 particulate matter 43 greenhouse gases 43 Fuel Consumption 43 Oxides 43 carbon emission reductions 43 8 CYL 43 isoprene 43 dioxide 43 Bioethanol 43 sulfur hexafluoride 42 flue gases 42 g l 42 kilotonnes 42 sulfur 42 warming gases 42 GHG reductions