Three new colours are now available for the vehicles which include 6C Villa d’Este Red, GT Junior Ocra, and Montreal Green - the latter hue pays homage to one of the brand’s iconic Alfa Romeo Montreal that was launched 50 years ago.
Both vehicles have been equipped with a 2.9-litre twin-turbo V6 petrol engine, producing 510hp and 600Nm of torque.
Managing power is an eight-speed automatic transmission for the all-wheel-drive system with active torque vectoring for both vehicles with gear changes achieved in 150 milliseconds when in Race mode.
Adding to the power is its active suspension system, Alfa DNA Pro driving mode selector and the Giulia's active aero splitter - all coordinated and adapted in real-time by the Alfa Chassis Domain Control.
Trumpeting the power is a dual-mode quad exhaust system that can be accompanied by an optional titanium Akrapovič exhaust system with carbon fibre finishers.
The duo has been equally equipped with new LED rear smoked light clusters, gloss-black finish surrounds the front tri-lobe and rear badges as well as 21-inch wheels.
The front sports a V-insert for the front grille in carbon fibre designed by Mopar including the mirror caps and rear spoiler.
Inside, the cabin is touted to be more practical with added storage space while being wrapped in leather on the steering wheel and gear knob as standard while the standard sports seat upholstery or optional carbon shell Sparco seats use perforated leather and Alcantara combination.
As an optional extra, red or green seat belts are available for choice over the standard black.
The infotainment system uses an 8.8-inch central touchscreen display featuring connected services and a new interface design meant exclusively for the Quadrifoglio models.
The new Performance Pages show the temperatures of the main mechanical components, torque delivery, turbo pressure and power usage, as well as digital chronometers to measure acceleration and maximum speed in real-time.
The Giulia and Stelvio Quadrifoglio now come with the carmaker's new Advanced Driver Assistance Systems (ADAS) developed in conjunction with Bosch to offer a level 2 autonomous driving system.
The system only intervenes to ensure total safety and to help maximise driver comfort in stop-go traffic or while cruising along highways.
The Level 2 autonomy, the highest level of autonomous driving currently permitted, allows the driver to give the car control of the accelerator, brakes and steering under certain conditions. The driver, however, must remain in control of the vehicle, by always keeping their hands on the steering wheel.
For added safety, the Giulia and Stelvio feature lane keep assist, active blind spot assist, adaptive cruise control with traffic sign recognition system, intelligent speed control, traffic jam assist, highway assist and driver attention assist.