Alfa Romeo Giulia Owner's Handbook Manual page 220

Tyres
225/40 R19
225/40 R19
255/35 R19
If winter tyres are fitted, always use the same inflation pressures as for the tyres originally installed (table above).
214) If winter tyres with a lower speed rating than that indicated in the Registration Document are used, do not exceed the maximum speed
corresponding to the speed rating of the tyres used.
218
Unladen/medium load [psi / bar]
Front Rear
34.8 / 2.4 37.7 / 2.6
34.8 / 2.4
– 33.4 / 2.3
WARNING
Front
39.2 / 2.7
– 39.2 / 2.7
–
Full load [psi / bar]
Rear
43.5 / 3.0
–
42.2 / 2.9