Thermal performance of automotive lighting must be considered early in the design phase of any lighting program. Several techniques are used to determine if a new design will pass thermal requirements. Many automotive lamps are design from experience, where historical information is used to qualify a design. Quantitative methods for determining lamp thermal performance allow optimization of parameters, which can affect lighting cost. This paper will present a comparison between experimental based modeling and computational fluid dynamics (CFD) approaches for determining the viability of an automotive lamp design.