head to head
Neither is harder. They score identically on all four axes, so the difference between them is in kind, not degree.

Execution · Pure Mechanics
Open-world racing testing car control and line discipline with light tuning underneath.

Execution · Pure Mechanics
Tests off-road handling and freeform route choice across an enormous open map.
Forza Horizon 2 leans Execution (Pure Mechanics); Fuel leans Execution (Pure Mechanics).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Forza Horizon 2
Racing lines, braking points and car control lead everything
Fuel
Off-road vehicle control through weather events is the core test
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Forza Horizon 2
Drivatar AI mimics styles but stays effectively scripted
Fuel
AI racers rubber-band on scripts; online is thin
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Forza Horizon 2
Weather shifts grip slightly; courses are fully known
Fuel
The huge map is scripted-but-unknown until explored
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Forza Horizon 2
Car tuning and route knowledge reward preparation
Fuel
Route choice across open terrain rewards planning
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.