A method to control combustion in an HCCI engine, to mitigate effects of combustion chamber deposits is detailed. The method comprises applying a specific surface coating to a combustion chamber surface. The surface coating has thermal properties substantially similar to the combustion chamber deposits. The thermal properties preferably include a) thermal conductivity, b) heat capacity, and c) thermal diffusivity. Applying a surface coating results in a reduction of combustion variability due to variation in combustion chamber deposits, and an improvement on combustion stability at low loads due to reduced heat loss. A preferred thermally insulating surface coating includes thermal parameters of a heat capacity in a range of 0.03×106 J/m3-K to 2.0×106 J/m3-K; a thermal conductivity in a range of 0.25 W/m-K to 2.5 W/m-K; and, a thermal diffusivity in a range of 1×10−7 m2/s to 8×10−6 m2/s.