Example:
15 meter per US gallon = 3.962581e-9 Gm/L
1 meter per US gallon = 2.641721e-10 Gm/L | 1 Gm/L = 3.785412e+9 meter per US gallon
Conversion Steps:
15 × (0.264172052 / 1e+9) = 3.962581e-9