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

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

Execution · Practiced Mastery
An open-world racer where tuning and racing lines beat the AI field.
Dirt 3 leans Execution (Practiced Mastery); Forza Horizon 5 leans Execution (Practiced Mastery).
Dirt 3 leans a little harder on execution, though the gap is small.
Dirt 3
Car control on loose surfaces is a high physical ceiling
Forza Horizon 5
Racing line, throttle control, and braking timing matter.
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
Forza Horizon 5
AI drivivatars follow fixed patterns; no real adaptation.
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Dirt 3
Surface conditions and minor physics noise per run
Forza Horizon 5
Weather and event roulette add mild randomness.
Forza Horizon 5 leans a little harder on optimization, though the gap is small.
Dirt 3
Stage knowledge and setup tuning reward study
Forza Horizon 5
Car tuning, build choice, and tire compound solve races.
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.