This paper enhances Model-in-the-Loop (MIL) test- ing for real-time systems using model-based mutation analysis. We introduce mutation operators for Simulink models based on AUTOSAR, addressing temporal correctness in Simulink-to-OS task mapping. Our framework reveals task interference issues in implicit clock Simulink models, supporting automated mutation testing. Our proposed Timed mutation operators for ML/SL models are used to evaluate tool with a timed task model for enhanced MIL simulation.