This study provides an understanding about lightning impulse characteristics of mineral oil used in transformers and other high voltage applications. The withstand capability of mineral oil is studied under various experimental conditions, such as different electrode spacing, electrode type, nanofiller type and filler concentration. Experiments are carried out for 5 mm and 10 mm interelectrode gaps. Different electrode configurations such as needle-sphere and needle-plane electrodes are used. Nanofillers such as SiO₂ and carbon quantum dots (CQD) treated SiO₂ nanoparticles are used in various concentrations such as 0.01% weight, 0.05% weight and 0.1% weight of mineral oil. Comparison is done for positive and negative polarities of lightning impulse test voltages. From the experimental results, it follows that the influence of nanoparticles to deliver better results in impulse withstand capabilities of commercially used mineral oil with improved performance in lightning impulse to withstand strength.