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

Execution · Practiced Mastery
Precise rally car control over stages that reward memorisation and tuning.

Execution · Practiced Mastery
An encyclopedic driving simulator spanning 700 cars and decades of automotive history.
Dirt 3 leans Execution (Practiced Mastery); Gran Turismo 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.
Dirt 3
Car control on loose surfaces is a high physical ceiling
Gran Turismo 4
Hundreds of cars all demand precise inputs
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Dirt 3
Racing the clock or scripted AI, nobody adapts
Gran Turismo 4
Fixed-line AI offers no adaptive opposition
Dirt 3 leans a little harder on variance, though the gap is small.
Dirt 3
Surface conditions and minor physics noise per run
Gran Turismo 4
Deterministic outside slight tyre wear modelling
Gran Turismo 4 leans a little harder on optimization, though the gap is small.
Dirt 3
Stage knowledge and setup tuning reward study
Gran Turismo 4
Event-by-event car and tune selection is deeply solvable
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.