head to head
Project CARS asks more than Grand Theft Auto V, and the gap is execution.

Execution · Practiced Mastery
Sandbox crime playground spanning shooting, driving, and a persistent online economy.

Execution · Practiced Mastery
Simulation driving precision underpinned by setup tuning and race strategy.
Grand Theft Auto V leans Execution (Practiced Mastery); Project CARS leans Execution (Practiced Mastery).
Project CARS leans clearly harder on execution.
Grand Theft Auto V
Driving and shooting demand decent inputs.
Project CARS
Braking points and wheel control at the sim limit
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Grand Theft Auto V
Online PvP exists but mostly gear/positioning, not modeling.
Project CARS
Online racecraft against humans adds light positional prediction
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Grand Theft Auto V
Some mission and lobby randomness.
Project CARS
Dynamic weather injects some session randomness
Project CARS leans clearly harder on optimization.
Grand Theft Auto V
Heists, money loops, builds learnable.
Project CARS
Setup tuning and pit strategy reward deep study
A matching score does not mean a matching test. Two games can both sit at 10 on execution and demand completely different things of you - which is why the reasoning above matters more than the number beside it.