What is one advantage of 4-stroke cycle engines?

• A. Higher emissions of pollutants
• B. Better fuel consumption rates
• C. Higher maintenance requirements
• D. Lower mean effective pressure

Answer: (B)

The advantage of 4-stroke cycle engines being better fuel consumption rates is primarily due to their design and operating cycle. In a 4-stroke engine, each cycle of combustion is spread out over four strokes of the piston (intake, compression, power, and exhaust). This design allows for a more complete combustion of fuel and air, which leads to more efficient energy conversion and reduced fuel consumption.

Additionally, the engine's operation provides a dedicated exhaust phase that minimizes the chance of unburned fuel leaving the combustion chamber. Consequently, this results in improved thermal efficiency. By utilizing fuel more effectively, 4-stroke engines tend to get better miles per gallon compared to 2-stroke engines, which burn oil along with the fuel and have less efficient combustion processes.

The other choices reflect disadvantages or characteristics that do not align with the 4-stroke engine's strengths, making better fuel consumption rates a clear and significant advantage.