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

Execution · Pure Mechanics
A time-trial racer testing millisecond steering precision along studied ideal lines.

Execution · Pure Mechanics
Futuristic sequel to the Trials physics-bike series with FMX tricks and brutally precise tracks.
TrackMania United leans Execution (Pure Mechanics); Trials Fusion 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.
TrackMania United
Hundredth-second steering precision over stunts decides every leaderboard
Trials Fusion
Frame-tight balance and throttle inputs
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
TrackMania United
Ghost-style multiplayer never interacts with your car
Trials Fusion
No adaptive opposition
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
TrackMania United
Tracks are perfectly deterministic
Trials Fusion
Deterministic physics, known tracks
TrackMania United leans a little harder on optimization, though the gap is small.
TrackMania United
Finding the ideal line is a study discipline of its own
Trials Fusion
Optimal lines and trick scoring are learnable
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.