Vanthoor was fastest in Friday's GT Le Mans practice for the Cadillac Grand Prix of Sebring at Sebring Raceway. He turned a fast lap of 1.59.501.

In GT Le Mans opening practice for the Rolex 24, Porsche led the way, which ran first and second with its new 2019-spec Porsche 911 RSR. Vanthoor set the pace with a time of 1:57.031 while Nick Tandy backed up his teammate with a 1:57.351, sportscar365.com reports.

Porsche's Vanthoor resisted a late surge of times from Jan Magnussen, Ryan Briscoe and Joey Hand to clinch pole for Sunday's Michelin GT Challenge at VIR. Vanthoor posted a time of 1:40.630 on his third flying lap with just under three minutes of the 15-minute session remaining to go fastest, but didn't improve further, sportscar365.com reports.

Vanthoor set Porsche on top of the timesheets in the opening practice session for this weekend's IMSA WeatherTech SportsCar Championship round at VIR. The Belgian driver posted a time of 1:41.296 behind the wheel of the GT Le Mans points-leading No. 912 Porsche 911 RSR to beat his teammate Nick Tandy by 0.139 seconds, sportscar365.com reports.

Vanthoor produced a late improvement to give Porsche its own sweep of the practice session times in the GT Le Mans class. The Belgian driver set his fastest lap of 2:01.644 in the No. 912 Porsche 911 RSR right at the end to cancel out a potential 1-2 for BMW Team RLL, sportscar365.com reports.