The manufacturing sector is a driver of the global economy and automotive industry is one of the most important manufacturing industry because contributes in high level to the competitiveness of the nations. The success in the automotive industry depends on the performance of a company’s suppliers. Supported in an exhausted literature review a part supplier’s competitiveness measurement instrument was defined and used to conduct a research study with Tier1 auto part suppliers of the State of Nuevo León, México. By the use of statistics methods as Cronbach’s alpha and linear regression, the present research finds the quality and lean manufacturing with positive impact in the manufacturing competitiveness of part suppliers of automotive industry.  This study presents the analysis and results of this factors and its discussion.