Technician A states a typical electronically controlled CI engine has thermal efficiency exceeding 40%. Technician B states 90% of the heat created from burning fuel in a CI engine ends up as rejected heat. Which technician is correct?
A) Technician A only.
B) Technician B only.
C) Both A and B.
D) Neither A nor B.

Question

Quizplus · Accepted Answer

Technician A is correct because modern electronically controlled Compression Ignition (CI) engines can achieve thermal efficiencies exceeding 40%, especially in large applications like marine and stationary engines. Technician B is incorrect because while a significant portion of the heat from burning fuel is indeed rejected (via the cooling system and exhaust), stating that 90% is rejected is an overestimation. The actual percentage of rejected heat in efficient CI engines is lower, making the statement inaccurate.

Technician a States a Typical Electronically Controlled CI Engine Has