In 1990, Alfa Romeo introduced the Quadrifoglio Verde, the first of two performance variants offered for the Alfa 164, the Quadrifoglio Verde (QV) featured a powerful V6 engine as well as dynamic and styling improvements, making it easier to identify from more standard models. In 1993, Alfa released the Q4, which was largely similar to the QV, but featured a four wheel drive system. These Quadrifoglio variants were the most desirable of the Alfa Romeo 164 cars.