Suppose you wanted to design an Otto cycle engine with the same power output as the two jet engines powering the fire truck. Suppose your Otto cycle engine was able to achieve the far higher efficiency of η_mech = ½ and η_Otto = 2/3. Suppose you operated the engine at 4.00 × 10³ RPM and (A/F)_Mass = 16.0 (kg air)/(kg fuel). Suppose your fuel was isooctane, with HV_fuel = 45,500 kJ/kW. How large would the displacement of the Otto cycle engine have to be in order to achieve the fire truck’s power output of 1.20 × 10⁴ hp? (A: 0.28 m³)

Involve the world’s fastest truck record holder, a 1940 Ford fire truck. Its top speed is 404 mph! It was powered by two Rolls Royce 601 Viper jet engines with afterburners, developing an equivalent to 1.20 × 10⁴ HP. It consumes 2.0 × 10² lbm of fuel per second (see http://www.jetfiretruck.