What type of fuel is primarily used in the Cessna 172?

The Cessna 172 primarily uses 100LL Avgas, which stands for 100 octane low-lead aviation gasoline. This type of fuel is specifically formulated for aviation piston engines, ensuring optimal performance, combustion efficiency, and safety at high altitudes. 100LL is designed to reduce the potential for engine knock, a critical factor when operating at the higher power settings typical in general aviation.

In contrast, JET A is a type of jet fuel intended for turbine-driven engines, making it unsuitable for the piston engine of a Cessna 172. Diesel fuel is also not applicable, as the 172 is not designed to operate with diesel engines. Mogas, which refers to automotive gasoline, may be used in some later models of the Cessna 172 with specific engine compatibility, but 100LL is the standard fuel widely endorsed for ensuring engine performance and adherence to manufacturer guidelines. Thus, 100LL Avgas is the correct fuel type for consistent and reliable operation of the Cessna 172.