Two families of PCA based combustion model were recently developed score-PCA and MG-PCA. This paper presents the first comparative study of the two aftermentioned methods. Both methods are first benchmarked on 1-D laminar flames of hydrogen-air and syngas-air, to verify the consistency of the approaches. The sensitivity to differential diffusion is carefully addressed and a rotation technique is proposed, to allow for using score-PCA with differential diffusion. Then, 2-D flame-turbulence interactions are considered, spanning a wide range of velocity and length scale ratios, to demonstrate the ability of PC-based combustion models to efficiently capture the behavior of different combustion regimes, from flamelet-like flames to distributed reaction regimes. (C) 2016 The Combustion Institute. Published by Elsevier Inc. All rights reserved.