Thank you, I agree not to mess the oil formulation especially on newer car. however on this case, the mixture is to address the high mileage engine that start consuming oil. since the MoS2, MOS and 5w-40 oil alone does not really reduce the oil consumption and seems makes the engine sound worse (for MOS), i have tried to add the MoS2 on the current oil. Interestingly the sound and mpg getting better, however just wonder if there is really problem to mix those two in the oil.