Turbo at altitude
Charge air through an illustrative 2026 power unit, from the airbox to the tailpipe. Four steps from the airbox to the tailpipe, each with what the thin air of Mexico City (2,240 m) changes, and a chart of pressure and temperature along the way.
With no MGU-H, the turbo takes about 1.7× as long to spool up in Mexico City, whatever the boost.