Every watt that doesn't become motion becomes heat, and heat is the powertrain's only real predator. Hold maximum attack in a 45 °C desert and find out what "derating" feels like.
Pick a terrain, set your sustained power, and keep the motor under its 110 °C limit. Above it, the MCU cuts power to save the magnets: that is derating.
Notice the Arctic paradox: powerful natural cooling, but a freezing battery gives less power until it warms up. Every terrain fights you differently.
An electric powertrain is brilliantly efficient, but even 95% efficiency at 400 kW means 20 kW of heat: a dozen kettles boiling inside the motor and inverter, lap after lap. It has to go somewhere, fast.
Magnets weaken and electronics fail above their thermal limits, so the control unit cuts power before damage happens. You felt it in the lab: request 400, receive 260. The car that manages heat best keeps its full power longest.
Desert air at 45 °C barely cools at all; Arctic air cools brilliantly but chills the battery below its happy zone. Thermal strategy changes with the map: which is exactly what Stage 06 will make you do.