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
Arcade racing with Mario Kart-style power-ups bolted onto licensed cars.

Execution · Pure Mechanics
Demolition derby racer with destructible PvP chaos.
Blur leans Execution (Pure Mechanics); Wreckfest 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.
Blur
Racing lines and dodging shots demand car control
Wreckfest
Demolition driving, ramming angles
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Blur
Human racers bait and time power-ups against you
Wreckfest
Online derby PvP rewards ramming reads
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Blur
Power-up pickups and incoming attacks add chaos
Wreckfest
Crash physics chaos
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Blur
Track knowledge and pickup routes are learnable
Wreckfest
Car upgrades and durability tuning
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.