Liquid fuels play a dominant role in transportation and power generation and it is not expected that this will change in the foreseeable future.  At the same time, the present volatility of oil prices and issues associated with fuel availability and the environment, have generated an urgent need for their more efficient and environmentally benign use.  While traditional engineering has achieved major advances in engine technology, further improvements will be at best incremental unless a better understanding of the science behind the controlling processes of the combustion of those fuels is obtained.  Gasoline, Diesel, and jet fuels typically contain hundreds or even thousands of components.  Simulation of their combustion characteristics becomes prohibitively difficult at a fundamental level.  Fuel surrogates, typically mixtures of a small number of neat hydrocarbon compounds, can be used to mimic the physical and chemical characteristics of real fuels.  Thus, the combustion of a single surrogate component or a mixture of these components can be examined experimentally and simulated accurately using detailed chemical kinetic models.  Higher molecular weight compounds dominate the composition of all practical fuels.  While experimental data are abundant for low molecular weight gaseous hydrocarbons, they are scarce for the heavier liquid counterparts, typically with carbon number greater than 5.  Given the importance of the surrogate fuels in current efforts towards science-based design of fuel-flexible engines, there is a growing interest in developing a fundamental database of combustion properties for neat liquid hydrocarbons and their mixtures.  In this lecture, on overview of current research of the combustion of low-vapor pressure heavy liquid fuels will be given.  In particular, the needs, challenges, and opportunities will be emphasized.