They tried to run the lower dwf rear wing because the engine needs to be detuned due to concerns about turbo reliability at this altitude, according to smilextech
FERRARI: There is a concern about turbo overheating, not so much for QP as for the race, given the Mexican environmental conditions. The aero was supposed to help the power unit, which is why they wanted to try to run with the medium-high load set-up.
However, it did not work on the tyres and we reverted to the most suitable aerodynamic configuration for Mexico, namely the high load. The abnormal weekend with virtually useless FP2 certainly didn't help.
Echoes AMuS