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
Tests off-road handling and freeform route choice across an enormous open map.

Execution · Pure Mechanics
Retro arcade racer channeling Top Gear's pure lane-weaving speed.
Fuel leans Execution (Pure Mechanics); Horizon Chase Turbo 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.
Fuel
Off-road vehicle control through weather events is the core test
Horizon Chase Turbo
Weaving through traffic and nailing fuel pickups
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Fuel
AI racers rubber-band on scripts; online is thin
Horizon Chase Turbo
Rival cars run fixed rubber-band logic
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Fuel
The huge map is scripted-but-unknown until explored
Horizon Chase Turbo
Minimal randomness in track layouts
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Fuel
Route choice across open terrain rewards planning
Horizon Chase Turbo
Car stats and lap memorization help
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.