Related by context. Frequent words. (Click for all words.) 77 diesel fuel 72 diesel engines 71 diesel engine 71 diesel powered 69 fuel 69 diesels 66 gasoline 65 petrol 63 CNG 63 LPG 62 biodiesel 61 bio diesel 61 low sulfur diesel 59 liter diesel 59 Diesel 58 unleaded fuel 57 compressed natural 56 cleaner burning 56 liter 56 cleaner fuels 55 unleaded petrol 55 kerosene 55 exhaust emissions 54 alternative fuels 54 ethanol blended 54 Fuel 54 unleaded gasoline 54 petroleum 53 fuels 53 #.#L [001] 53 petrol diesel 53 unleaded 53 internal combustion engine 53 biofuel 52 liquefied petroleum gas 52 gas 52 ethanol blends 52 powerplants 52 Petrol 52 bio ethanol 52 flex fuel 51 Civic Hybrid 51 Biodiesel 50 bioethanol 50 internal combustion engines 50 combustion engine 50 ethanol 50 fossil fuel 50 V6 engine 50 sulfur 50 combustion engines 50 bio fuels 50 octane 49 Gasoline 49 gallon 49 urea 49 crude oil 49 powertrains 49 #hp [001] 49 gas guzzler 49 E# ethanol 49 E# [004] 49 powerplant 48 emission norms 48 #hp [002] 48 liquid fuels 48 engines 48 fossil fuels 48 emission 48 #.# liter V6 48 hatchbacks 48 V6 48 biofuels 48 tailpipe emissions 47 vehicles 47 hybrids 47 liter petrol 47 polluting 47 renewable fuels 47 natural gas 47 hydrogen fuel 47 naphtha 47 hydrogen powered 47 #mpg [002] 46 distillate 46 propane 46 SUVs 46 emissions 46 powertrain 46 electric hybrid 46 refineries 46 motor 46 butane 46 Elantra 46 gas guzzling 46 mpg 46 naturally aspirated 46 coal 46 internal combustion 45 NOx 45 driveability