Owing to increased consumption and consequent depletion of fossil fuels, it has become imperative to use the available reserves sensibly. Such prudent use contributes to reducing greenhouse gas emissions and mitigating the intensity of the consequences of global warming. The automobile and ancillary industries are major energy consumers in India. However, there stays a significant need for awareness of prudent energy use and practical energy-saving measures in this industry. This is particularly vital for small- and medium-scale industries, which are exempt from mandatory energy audit regulations and are also distant from the appointment of a dedicated energy manager. The present work aims to bridge the gap between the availability of technical ability and the grassroots-level understanding of possible energy-saving avenues in such industries, resulting from the obstacles. The current work presents key insights obtained from plant-wide energy audit of two auto-ancillary industries: a rubber-tube manufacturing plant and a casting and machining industry, carried out by a Certified Energy Auditor in India. Unlike earlier works, this audit has helped find energy-saving potential through electricity-bill analysis, compressor speed control, insulation upgrades for steam systems, and the application of microturbines for electricity generation. The energy-saving potential was assessed through temperature measurements of steam distribution and the hot-water system, with more than 400 observations; leakage testing of the compressor system; electricity-bill analysis for both plants and a techno-economic evaluation of replacing the pressure-reducing valve with a microturbine. It’s a novel study proving how energy savings in two distinct industries can be achieved despite variations in their operational characteristics and energy consumption patterns. Insulation upgrade of steam and hot water systems have savings potential of 91.94 MT fuel, 27.3 MWh electricity and 358.72 tCO2 per year. Replacement of the pressure reducing valve in RTM plant has yielded potential savings of 903.702 MWh electricity and 704.89 tCO2 per year. Arresting compressed air leakages in both the plants resulted in annual savings of 97.749 MWh and 76.24 tCO2. Total saving has been 1141 MWh electricity and 1,228.10 tCO2 per year. Notably, analysis of electricity bills has been widely used for energy conservation. This energy audit has found energy savings of 33.13% and 26.71% in the manufacturing and casting plants, respectively. This audit has helped plant management find energy-wastage hotspots and has further supported informed decision-making by prioritizing the implementation of energy-saving measures. In conclusion, energy audits have been recognized as a pragmatic tool for achieving energy conservation.