A fuel control system for a vehicle comprises a fuel control module, a heat release determination module, and a detection module. The fuel control module supplies fuel to a cylinder of a diesel engine for combustion within the cylinder. The heat release determination module determines a heat release value based on a pressure within the cylinder during the combustion. The detection module selectively indicates that the fuel is a diesel fuel alternative when the heat release value is less than a predetermined heat release value. The predetermined heat release value is less than a second predetermined heat release value associated with diesel fuel.