Describe the engine calibration process from base maps to production release.

Engine calibration process includes: Base map development on dynamometer covering full speed-load range, transient calibration for drive cycle performance, emissions calibration meeting WLTP/FTP requirements with margin, cold start optimization, altitude and temperature compensation, OBD-II diagnostic calibration, production variability robustness verification, and durability validation. Tools include automated DoE-based optimization, physics-based models, and hardware-in-loop testing. Calibration involves thousands of parameters including fuel, spark, VVT, boost, and EGR maps. Final validation includes real-world driving on multiple continents with production-intent hardware.