Aside from Scottie Scheffler's victory, the biggest storyline of the PGA Championship was the driver test that took place before the start of the event. Famously, Rory McIlroy's driver failed the test, but it wasn't the only one, as the champion himself revealed.Scheffler confirmed what had been rumored for much of the weekend, that his driver had also been declared non-compliant, as had McIlroy's. Faced with this eventuality, the World No. 1 had to rely on a substitute he had with him."The driver testing is something that regularly happens on Tour. My driver did fail me this week," Scheffler said. " We had a feeling that it was going to be coming because I've used that driver for over a year. I was kind of fortunate for it to last that long, I felt like."This way, Scheffler confirmed what many pundits have said about McIlroy's driver failing the test: It is completely normal and has little or no impact on his past success.As a comparison, in the case of the now three-time major winner, his driver would have helped him win seven PGA Tour events last season and another just two weeks ago. All within the current rules.However, the Ridgewood, New Jersey, native believes the process needs to be refined, with more input from key stakeholders:"I would argue that if we're going to test the drivers, we need to be even more robust in the way we test them," he said. "That was a conversation I had with one of the rules officials; if it's something we're going to take seriously, I feel like we're almost going halfway with it right now.""If we're going to do it right, leave it up to us as players, like the rest of the rules in the game of golf are. It's a newer rule that we haven't quite gotten right yet. I think we have some stuff to figure out."Unlike McIlroy, the forced driver change did not have a severe impact on Schffler's driving. The 2025 PGA Championship winner was fifth in the field off the tee with 1,209 strokes gained, although his average driving distance and accuracy percentage were not up to his usual performance (308.4 yards and 62.5%, respectively).To win the event, Scheffler compensated with his exceptional iron play (1.189 strokes gained approaching the green) and his skills around the green (1.208 strokes gained). He also had a good weekend with his putting (0.781 strokes gained), which allowed him to lead the field in total strokes gained (4.348).More Golf: PGA Championship 2025: $19M payout as Scottie Scheffler wins $3.42M