Related by context. Frequent words. (Click for all words.) 68 ethanol methanol 67 gaseous fuels 62 hybrid powertrains 62 conventional internal combustion 61 renewable feedstocks 60 diesel 59 compression ignition 57 alternative fuels 57 combustion engines 57 diesel engines 57 diesel engine 57 powerplants 57 cellulosic materials 56 internal combustion engines 56 reciprocating engines 56 cellulosic feedstocks 56 alkanes 55 bio fuels 55 biodiesel 55 bio diesel 55 B# biodiesel [002] 55 compressed hydrogen 55 diesels 55 gasifiers 55 Bioethanol 55 bio ethanol 54 spark ignition 54 cellulose ethanol 54 turbocharged engines 54 internal combustion 54 BlueTec 54 dry sump 54 liquefied coal 54 halogenated 53 nonpolluting 53 NGVs 53 electric drivetrain 53 internal combustion engine 53 drivelines 53 drivetrains 53 autogas 53 synthetic lubricants 53 soy biodiesel 53 fuels 53 battery chemistries 53 sugar cane ethanol 53 hybrid drivetrain 53 efficient powertrains 53 hydrogen 53 organic solvents 52 turbo diesel engine 52 isobutanol 52 smog forming 52 combustion 52 Fischer Tropsch 52 particulate filters 52 ethanol 52 BioWillie 52 hydrocarbon fuels 52 propylene oxide 52 electrolyzer 52 biofuels 52 #.# liter Duratec 52 polluting fossil fuels 52 petrochemical feedstock 52 lubricating oils 52 fuel 52 biofuel 51 biobutanol 51 oxidizers 51 biodiesel blends 51 diesel engined 51 diesel fuel 51 sorbents 51 BEVs 51 thermochemical 51 evaporative emissions 51 environmentally benign 51 Lithium Ion batteries 51 proton exchange 51 bioethanol 51 V6 diesel 51 sulfur fuels 51 Selective Catalytic Reduction SCR 51 Autogas 51 AuraGen 51 hydrocracking 50 cleaner fuels 50 exhaust emission 50 diesel powered 50 renewable fuels 50 byproducts 50 8 CYL 50 Cellulosic ethanol 50 carbureted 50 biopower 50 hydrogen internal combustion 50 chemical solvents 50 Cellulosic 50 biomass 50 drivetrain components