More than half of the field have taken new engines for this race: Both Mercedes, McLarens, Aston Martins, Saubers and Haas, plus Colapinto at Williams, who has taken over Sargeant's stock of motors.
It probably wasn't that powertrain in the car for FP1. Usually the new engine makes in the car by FP3 or even quali. Even on normal weekends without a new engine, and especially later in the season, teams would run an "FP1 engine" on Friday to minimize mileage on a different engine for the more demanding circuits.