Van der Zande, who won the last two Rolex 24 Hours in Wayne Taylor Racing’s Cadillac, lapped the 3.56-mile road course in 1min34.649sec to shade Mike Conway’s best effort in the similar DPi-V.R of Action Express Racing by just 0.082sec.
Third was Harry Tincknell in the Mazda RT24-P ahead of Ricky Taylor of WTR which this year runs one of the Acura ARX-05s.
JDC Miller MotorSports’ Cadillac was fifth fastest, 0.3sec off top spot in the hands of Loic Duval, while Simon Pagenaud was sixth in the second Action Express Cadillac, just under half a second behind P1, although the 2016 IndyCar champion appeared to suffer a power outage during his spell behind the wheel.
The 2019 IMSA champion Dane Cameron was seventh in the Meyer Shank Racing Acura.
Nicolas Lapierre was predictably fast in the PR1/Mathiasen Motorsports Oreca to head the LMP2 field ahead of Ben Hanley in one of DragonSpeed’s two entries. Racing Team Nederland claimed third thanks to Job van Uitert.
In LMP3, new to the IMSA WeatherTech SportsCar Championship this year, Jeroen Bleekemolen in Riley Motorsports’ Ligier was 0.45sec quicker than his nearest rival, Colin Braun in the similar CORE autosport machine, while late signing Kenton Koch was third for Muehlner Motorsports in the #6 Duqueine-Nissan.
Tommy Milner and Antonio Garcia, 0.3sec apart, put Corvette Racing 1-2 in GT Le Mans, the team stalwarts having not been part of the 100-minute qualifying race last Sunday.
Jules Gounon was third in the Risi Competizione Ferrari 488, who in turn was 0.2sec ahead of Richard Lietz in the new WeatherTech Racing Proton Porsche 911 RSR. The faster of the two BMW M8s, Bruno Spengler’s #25 entry, was 1.2sec off Milner’s Corvette.
Alegra Motorsports Mercedes-AMG GT3 steered by Billy Johnson emerged top of the GT Daytona class, mere hundredths ahead of Earl Bamber in the Team Hardpoint EBM Porsche 911 GT3 R, and the similar Pfaff Motorsports 911 of Matt Campbell.
Fourth was Andy Lally in the Magnus Archangel Acura NSX in front of Jack Hawksworth (Vasser Sullivan Lexus RC F) and Albert Costa (Grasser Racing Lamborghini Huracan).
The other Grasser Lambo caused one of two red flags in the session when it ground to a halt on track, while Cody Ware in the RWR Eurasia LMP2 Oreca caused the other when it slapped a wall.
Second practice commences at 3.20pm local (Eastern) time.