Related by context. Frequent words. (Click for all words.) 52 piston engine 47 combustion engines 46 engines 45 turbocharged engines 45 turbofan 44 aero engines 44 turbine engines 43 propulsion 43 spark ignition 43 engined 43 powerplants 42 electric propulsion 42 turbochargers 42 internal combustion 42 diesel engines 42 internal combustion engines 42 cylinder deactivation 41 motors 41 hybrid powertrains 41 V#s [001] 40 intercooled 40 diesels 40 superchargers 40 aftertreatment 40 rotary engine 40 turbo 40 turboprop engines 40 electric motors 40 hybrid propulsion 39 diesel powered 39 carburetors 39 jet engines 39 engine 39 hydraulic steering 39 sportbikes 39 rear engined 38 centrifugal pumps 38 twin turbochargers 38 nitrogen oxide NOx 38 turbo diesel engine 38 lithium polymer batteries 38 combustion turbines 38 drivetrains 38 GEnx 38 NiMH batteries 38 liquid cooled 38 injectors 38 Cosworth engine 38 hydraulics 37 propulsion systems 37 exhaust emission 37 internal combustion engine 37 ECUs 37 NOx emissions 37 particulate matter emissions 37 automobiles 37 gearboxes 37 V6 engines 37 turbocharged diesel 37 diesel engine 37 CVTs 37 exhaust emissions 37 Lithium Ion batteries 36 turbos 36 turbo charger 36 fuel injector 36 gearless 36 diesel engined 36 hybrid drivetrain 36 Selective Catalytic Reduction SCR 36 fuel injectors 36 combustion engine 36 hydraulic fluids 36 Turbocharged 36 Hemi engine 36 outboards 35 airframes 35 diesel 35 CSRV 35 hybrid electric 35 injector 35 piston 35 linear motors 35 airframe 35 valvetrain 35 dual overhead cam 35 NVH 35 BlueTec 35 driveability 35 acid batteries 35 petrol engined 35 horsepower 35 drivetrain 35 polluting fossil fuels 34 powerplant 34 Lithium ion 34 combustion 34 microturbine 34 gas recirculation 34 #.#L engine 34 NOx