What effect does using higher aromatic content fuels have on engine materials?

Using higher aromatic content fuels significantly impacts engine materials, particularly rubber components. Aromatic hydrocarbons can lead to the deterioration of rubber parts found in fuel systems, such as seals and gaskets. This occurs because aromatic compounds are more aggressive solvents than aliphatic hydrocarbons, causing the rubber to swell, soften, or even degrade over time.

As rubber deteriorates, it can compromise the integrity of the fuel system, leading to leaks and potential failures. The relationship between fuel composition and material compatibility is a critical factor in aviation fuel system design, making it essential to choose the right type of fuel that does not adversely affect the materials used in the engine and fuel system.

While increased lubricity with certain fuel types can be beneficial for engine performance, and higher aromatic content could theoretically offer some efficiency benefits due to better combustion characteristics, the primary concern regarding the materials compatibility results in the negative effects outlined in the correct answer.