Higher energy efficiency is the most important aim in the use of fossil fuels in combustion processes. Part of the generated energy can be used to improve the air-fuel ratio and operating conditions of the flame. The chemical composition of LPG means energy can be generated through its combustion reaction. By varying the gas composition, a low amount of excess air could be used in a burner for manufacturing ceramic tiles whilst also reducing pollutants. With a pilot furnace it was possible to reproduce the working state of an industrial burner, while measuring the combustion products and checking the process efficiency for different air-fuel ratios. It was noticed that LPG with a high percentage of propane increased the burning efficiency by 20%. Some excess air levels were applied in the experimental work, and it was determined that, for a wide range of commercial LPG compositions, stoichiometric combustion achieves the highest efficiency. For the compositional variances studied, adjustments in the air-fuel ratio showed a variation in the process efficiency by up to 20% when directly measured in fuel consumption.