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 · Pure Mechanics
Punishing rally car control at the limit, supported by setup and stage knowledge.
Dirt 3 leans Execution (Practiced Mastery); Dirt Rally leans Execution (Pure Mechanics).
Dirt Rally leans a little harder on execution, though the gap is small.
Dirt 3
Car control on loose surfaces is a high physical ceiling
Dirt Rally
Unforgiving car control on loose surfaces is the entire test
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
Dirt Rally
Solo time trials against the clock, no adaptive rival
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
Dirt Rally
Weather and surface degradation vary between stages
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Dirt 3
Stage knowledge and setup tuning reward study
Dirt Rally
Pacenote interpretation, setup tuning and stage memorisation
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.