A steering wheel is by and large the preferred method for posting fast times in racing games. You can certainly do well with a gamepad, but you’ll find yourself lacking the granularity of control across things like acceleration, braking, and steering. Further, you have more space on a steering wheel, so your hands aren’t likely to fumble when switching gears or taking hairpin turns.
The major drawback with steering wheels is their overall expense compared to a gamepad. Gamepads come with the console while steering wheels are a fairly expensive investment for a gaming peripheral. There is a lot of work that goes into building these wheels, but their steeper price tag might not be attainable for most gamers.