Technician A states that #2D diesel fuel will, in most cases, produce slightly better fuel mileage from a highway truck engine than a #1D fuel. Technician B states that #2D usually has more heat energy than a #1D fuel. Who is correct? a. Technician A only b. Technician B only c. Both A and B d. Neither A nor B
The Correct Answer and Explanation is :
Correct Answer: c. Both A and B
Explanation:
Diesel fuels are categorized based on their properties and applications, with #1D and #2D being the most common grades. Here’s why both technicians are correct:
Technician A’s Statement
“#2D diesel fuel will, in most cases, produce slightly better fuel mileage from a highway truck engine than #1D fuel.”
This is true because #2D diesel fuel typically has a higher energy content per gallon compared to #1D diesel. The greater energy density of #2D fuel allows engines to extract more work from the same volume of fuel, leading to improved fuel economy. #2D diesel is also less volatile and more suited for high-load, steady-speed applications like highway driving, which further contributes to better efficiency in such conditions.
Technician B’s Statement
“#2D usually has more heat energy than #1D fuel.”
This is also correct. #2D diesel fuel generally has a higher BTU (British Thermal Unit) rating per gallon, indicating greater heat energy. This higher energy content makes #2D fuel more efficient for applications that require sustained power, such as long-haul trucking. On the other hand, #1D diesel, which is lighter and less energy-dense, is better suited for cold weather due to its lower viscosity and better flow properties.
Additional Notes
- #1D Diesel Fuel: It is more volatile, with lower energy content, but it is preferred in cold climates because it resists gelling and flows better at low temperatures.
- #2D Diesel Fuel: Heavier and more energy-rich, making it ideal for warmer climates and consistent highway driving.
In summary, both Technician A and Technician B are correct because #2D diesel fuel’s higher energy density results in better fuel mileage, and it does contain more heat energy than #1D diesel.