Which substance is commonly used for fuel system cleaning?

Solvent-based cleaners are commonly used for fuel system cleaning because they are specifically designed to dissolve and remove contaminants that can accumulate in fuel systems. These contaminants include carbon deposits, varnish, and other residues that can adversely affect engine performance and efficiency. Solvent-based cleaners are effective at breaking down these substances, allowing for thorough cleaning without causing damage to the components of the fuel system.

In contrast, water is not suitable for cleaning fuel systems because it can cause rust and corrosion in metal components and is not effective at dissolving hydrocarbon-based contaminants. Alcohol, while it can have some cleaning properties, does not work as effectively as solvent-based cleaners specifically formulated for fuel systems. Granular substances could potentially aid in cleaning but are not commonly used in modern fuel system maintenance practices, as they may not be able to reach all areas of the fuel system or could even cause blockages. Therefore, solvent-based cleaners are the preferred choice for maintaining the cleanliness and efficiency of fuel systems.