The purpose of this article is to attempt to answer the question of whether an extensive brand portfolio of an automotive concern allows it to gain an advantage and a larger market share compared to a competitor with a simpler brand portfolio. A research tool in the form of the Boston Consulting Group's BCG Matrix will be used as a research tool for the brand portfolios of the selected concerns and the determination of the companies' situation on the Polish market. On the basis of the data obtained, it can be seen that the two brands of the Toyota Motor Corporation exceed with their market share, by as much as 4%, all the brands of the Stellantis concern. It is noteworthy that Toyota alone has a market share of as much as 15 per cent, dominating all other brands participating in the study. In general terms, it can be seen that the extensive brand portfolio currently does not represent a construct that allows a competitive advantage. The performance of the two TMC brands clearly deviates from the indications for the entire Stellantis portfolio. The results presented have a practical dimension by indicating the strategic situation of individual brands as well as the portfolio of the concern as a whole. Visualisation using the BCG matrix allows deeper analysis and decision-making in relation to the group's brands. In the case of stakeholders, this analysis can be one of the determinants of purchasing or investment decisions.