Related by context. Frequent words. (Click for all words.) 48 diesels 47 turbocharged engines 47 diesel engine 46 diesel engines 44 diesel powered 42 cleaner burning 42 diesel 42 Fiesta subcompact 41 diesel particulate filter 41 Compressed Natural Gas 41 hybrid 41 internal combustion engines 41 particulate filter 40 internal combustion engine 40 cleaner fuels 39 exhaust emission 39 tailpipe emissions 39 Bluetec 39 electric hybrid 39 exhaust emissions 38 biodiesel blends 38 alternative fuels 38 hybrids 38 environmentally friendlier 38 gas guzzling vehicles 37 fuel 37 FFVs 37 selective catalytic reduction 37 conventionally powered 36 compressed natural 36 HEVs 36 combustion engines 36 CNG 35 nonpolluting 35 coal liquefaction 35 Bharat Stage 34 smog forming emissions 34 ULSD 34 PHEVs 34 microturbine 34 combustion 34 octane gasoline 34 nitrogen oxide NOx 34 gasohol 34 gasoline 34 ethanol blends 33 nitrogen oxide emissions 33 electric hybrids 33 flex fuel 33 hybrid electric 33 GHG reduction 33 zero emission 33 catalytic converters 33 microturbines 33 pellet stoves 33 renewable fuels 33 ethanol blended 33 E# ethanol 32 environmentally friendly 32 particulate emissions 32 E# blend 32 NOx emissions 32 LCFS 32 indirect 32 diesel fuel 32 Flex Fuel 32 emission 32 direct 31 pollutant emissions 31 emissions 31 biomethane 31 soy biodiesel 31 efficient 31 By Dave Toplikar 30 hydrogen 30 hydrogen fuel 30 petroleum refiners 30 low sulfur diesel 30 leaded gasoline 30 retrofitting 30 AppOne 30 Hydrogen 30 Clean Cities 30 autocatalysts 30 wood stoves 30 retrofits 30 Alternative Fuel 29 efficient compact fluorescent 29 unleaded fuel 29 carbon emitting 29 desulfurization 29 emission reduction 29 fossil fuels 29 bio ethanol 29 hydrogen powered 28 natural gas 28 biobutanol 28 editor@evworld.com 28 nitrogen oxides 28 fossil fuel 28 retrofit