Tetraethyl lead in aviation gasoline serves as a lubricant for which engine component?

• A. Pistons.
• B. Bearings.
• C. Valves.
• D. Camshafts.

Answer: (C)

The lubricating effect of tetraethyl lead in aviation gasoline mainly targets the valve train. Lead deposits form a thin lubricating film on valve stems and within valve guides, reducing friction and wear where the valve contacts the seat and moves in the guide, especially under high heat and rapid cycling. This helps prevent valve sticking and excessive wear in older engines. Other components like pistons, bearings, and camshafts rely on oil films supplied by the engine’s lubrication system rather than fuel additives, so the leading benefit of the lead additive is for the valves. So the correct component is the valves.