Which of the following is a common sign of fuel contamination?

A common sign of fuel contamination is the presence of sediment or particles in the fuel. When fuel becomes contaminated, it can pick up particulates from various sources, such as dirt, dust, or rust from storage tanks and lines. These contaminants can settle at the bottom of the fuel tank or be suspended in the fuel, creating a cloudy or murky appearance. This sediment can lead to clogs in fuel filters and injectors, affecting engine performance and efficiency.

While clear and bright appearance indicates clean fuel, a strong fuel odor may simply be a natural characteristic of the fuel rather than a sign of contamination, and rapid evaporation is not typically associated with fuel quality issues. Thus, identifying visible sediment or particles is the most direct and reliable way to detect contamination in fuel.