A critical examination of 10 existing alkane nonbonded empirical potential functions has been performed by computating various properties in all three phases. The evaluated properties include methane dimer energies, methane and butane second virial coefficients, liquid methane and butane enthalpies of vaporization, liquid densities, liquid methane C-C correlation functions, crystal unit cell parameters, unit cell volumes, and enthalpy of sublimation data. The potential functions have been selected to cover the widest range of potential functions currently available in molecular mechanics force fields. Ten new parameter sets have also been obtained based on various criteria to fit to ab initio and empirical properties. Bartell’s modified Urey-Bradley potential and a reparameterized version of Allinger’s MM3 function, termed MM3mc, have emerged as the two most reliable potentials. The relationships between properties in different phases have also been explored.