head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is reads, and it is a single point.

Execution · Practiced Mastery
Simulation driving precision paired with a deep, solvable tuning and setup layer.

Execution · Practiced Mastery
A serious F1 simulation testing precise car control and setup optimization.
Gran Turismo 5 leans Execution (Practiced Mastery); Grand Prix 4 leans Execution (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Gran Turismo 5
Simulation-grade car control and braking precision lead everything
Grand Prix 4
Precise braking, throttle and racing-line control define lap times
Grand Prix 4 leans a little harder on reads, though the gap is small.
Gran Turismo 5
AI fields are predictable; online racing stays positional
Grand Prix 4
AI drivers follow scripted lines, not adapting to you
Grand Prix 4 leans a little harder on variance, though the gap is small.
Gran Turismo 5
Tracks and physics are deterministic
Grand Prix 4
Weather and grip add some unpredictability per race
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Gran Turismo 5
Tuning setups, gear ratios and license-test lines are deeply solvable
Grand Prix 4
Setup tuning and optimal lines are a deep solvable layer
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.