1. Which statement correctly describes how four-stroke and two-stroke spark ignition engines are lubricated?
- A. Both engines circulate oil drawn from a pressurized crankcase sump
- B. A four-stroke uses oil mixed with the fuel, while a two-stroke uses pressurized crankcase oil
- C. Both engines are lubricated only by oil mixed with the fuel
- D. A four-stroke uses crankcase oil, while a two-stroke uses oil mixed with the fuel as a fog
Show the answer and explanation
Answer: D. A four-stroke spark-ignition engine keeps oil in the crankcase and delivers it by a pump or by splash from the crank. A two-stroke carries oil with the gasoline as a mist, either mixed into the fuel or injected on newer engines. Swapping those two methods, or treating both engines as lubricated the same way, does not match how they are built.