"Everyman's Jet Engine" - Why Valveless Pulsejets? Reasonable fuel consumption at low subsonic airspeeds At low speeds (i.e. typical "model airplane" speeds), no jet engine will be as fuel efficient as a conventional piston engine. However, modern valveless pulsejet designs can achieve reasonable fuel consumption figures, especially in higher speed classes of models, where piston-driven airscrew propulsion starts to lose efficiency. A few designs, when well-tuned, have been able to do better than 1.0 kg (mass) per hour of fuel per kg (force) thrust. That is considered very good fuel consumption for a small jet engine -- with the use of "thrust augmentor" technology, even lower consumption figures should be easily attainable.