🔍 Key Concepts

• Calorific value of a fuel and what affects it • How sulfur content in heavy fuel oil influences engine wear and corrosion • Relationship between fuel properties and actual fuel consumption rate of a diesel engine

💭 Think About

• Ask yourself: does sulfur mainly change the chemical energy content (BTU per unit mass) of the fuel, or does it mainly change how the fuel interacts with engine parts and lubrication? • Think about what causes increased fuel rate in a diesel: lower energy per unit fuel, poor combustion, or mechanical condition such as blow‑by and wear. • Consider whether sulfur’s primary effect is on combustion efficiency, metal corrosion, or mechanical wear that could indirectly change fuel rate over time.

✅ Before You Answer

• Verify whether sulfur is a major contributor to the fuel’s heating value compared with carbon and hydrogen. • Check which options talk about direct change in fuel energy content vs indirect effects like corrosion or wear. • Confirm whether sulfur, by itself, is known mainly for acid formation and corrosion or for significantly altering combustion efficiency in a properly maintained diesel.