<p>India&rsquo;s rapidly evolving digital economy has transformed the way businesses communicate with consumers, manage promotional activities and evaluate marketing performance. The growing use of social media, mobile internet and data-driven communication has created new opportunities for automotive companies to strengthen brand visibility, engage potential customers and support purchase decisions. However, increased digital engagement does not necessarily translate into lower promotional costs or improved business performance. In this context, the present study proposes to examine the relationship between social-media marketing capability and promotional cost efficiency among Hero MotoCorp, TVS Motor Company and Bajaj Auto, with particular reference to consumers in Indore district, Madhya Pradesh. The study adopts a quantitative, explanatory research design, targeting approximately 500 respondents, supplemented by verified company disclosures and campaign-level data wherever available. Its theoretical foundation integrates the Resource-Based View, Dynamic Capabilities Theory, Integrated Marketing Communications and consumer brand-engagement literature. Social-media marketing capability is conceptualised through content relevance, audience targeting, consumer interaction, cross-channel coordination, analytics and campaign optimisation. Consumer engagement is proposed as a mediating variable, while analytics capability is examined as a potential moderator of the relationship between marketing capability and promotional efficiency. Purchase intention and perceived marketing performance are considered downstream outcomes. A central methodological distinction is maintained between consumer-perceived promotional efficiency and objective efficiency indicators, such as cost per qualified lead and customer acquisition cost, which require comparable expenditure and outcome data. The proposed analysis will examine relationships among the study variables and compare the selected brands where sample adequacy and measurement equivalence permit. As primary data collection and statistical analysis have not yet been completed, the hypotheses remain untested and no empirical findings or company rankings are claimed. The study is expected to contribute to the understanding of digital marketing productivity in India&rsquo;s two-wheeler industry by developing a measurement-oriented framework that connects consumer engagement with the economic evaluation of promotional activities. Its conclusions will depend on data quality, construct validity, sampling adequacy and the availability of comparable campaign-level evidence.</p>