The plot in Figure presents a comparison of reaction enthalpies for alkane combustion, spanning carbon chains from methane (C₁) to decane (C₁₀). The enthalpies were computed using six different DFT methods employing two basis sets. Each panel in the figure represents a specific functional, where gray bars correspond to calculations with 6-31G(d) basis set, orange bars represent cc-pVDZ basis set, and red bars denote the experimental benchmark. A clear trend emerges, the cc-pVDZ basis set typically yields enthalpies closer to experimental values than 6-31G(d), reflecting its higher accuracy. Interestingly, functionals with dispersion corrections, such as B2PLYPD3, demonstrated better agreement with experimental data compared to their dispersion-free counterparts except LSDA. A study was carried on by Sai Sharath Yadavalli and his team on methane steam reforming (MSR) to benchmark DFT methods . They found that DFT-D (Density Functional Theory with Dispersion corrections) produced the best agreement with the experiment. Another study by Amir Karton et. al. benchmarked thermochemistry of alkane isomerization with DFT methods, and found that dispersion correction consideration produced best result . However, as the alkane chain length increases (C₁ to C₁₀), discrepancies between computational and experimental values grow, indicating that certain methods may struggle to accurately scale with molecular size. Notably, missing data for PBEPBE and TPSSh with 6-31G(d) limits a complete comparison for these cases. Overall, the plot illustrates the interplay between functionals, basis sets, and experimental data, shedding light on the strengths and limitations of each computational approach in modeling combustion enthalpies.