Tandy lapped the 3.56-mile road course in 1m35.617s in his GTP class, Penske-run 963 in pleasant and warm track conditions.
Last year’s pole time, set by Tom Blomqvist in Meyer Shank Racing’s Acura, was 1m34.031s.
Tandy was quick out of the blocks, setting his quickest lap in the factory-entered hybrid prototype in the early minutes of the session. His benchmark only came under attack in the closing moments when Augusto Farfus lapped his RLL-run BMW M Hybrid V8 in 1m35.652s, 0.035s slower.
The sister BMW of Nick Yelloly was third fastest, just over a tenth off the pace.
IndyCar champion Alex Palou was an impressive fourth in Chip Ganassi Racing’s Cadillac V-Series.R, just under a quarter of a second away from the fastest time. Jack Aitken was two tenths further back in the Action Express Racing Caddy.
Keeping the theme of quick IndyCar stars, Colton Herta outpaced Ricky Taylor to be the quickest Acura, lapping his Wayne Taylor-run ARX-06 within half a second of Tandy, with Taylor Jr a further tenth off.
Felipe Nasr (Penske Porsche) and Richard Westbrook (JDC-Miller Porsche) were eighth and ninth, respectively. In total, 58 cars took part in the session, with the Proton Competition Porsche 963 only running in the closing minutes in Neel Jani’s hands and was classified 23rd overall.
The session was red flagged just before the 30-minute mark to clear up debris at Turn 4 and was halted again with 20 minutes to go when Dennis Andersen spun his MDK by High Class Racing ORECA LMP2 car at Turn 5.
United Autosports fastest in LMP2
Mikkel Jensen set the early pace in his No. 11 TDS Racing ORECA at 1m40.648s. But, after an early off at Turn 3, Paul di Resta then achieved the quickest lap of the class in his No. 22 United Autosports ORECA at 1m39.916s.
Ferdinand Habsburg got within 0.031s in his Tower Motorsports ORECA, ahead of Nicklas Nielsen’s AF Corse version.
Legge on top in GTD for Acura
Katherine Legge set the quickest GTD time of the session in her No. 66 Gradient Racing Acura NSX with a lap of 1m46.289s. She set the mark early on, with Matteo Cressoni getting closest to it in his No. 60 Iron Lynx Lamborghini Huracan – which topped the GTD Pro category.
Nico Varrone proved rapid in AWA’s new Corvette Z06 GT3.R, setting the third fastest time to take US muscle car honors.
The quickest of the new Ford Mustang GT3s was Frederic Vervisch, who was sixth fastest, behind the Lambo of Andrea Caldarelli and Ferrari of Daniel Serra.
Contact was reported at Turn 3 between Tommy Milner’s No. 4 Chevrolet Corvette Z06 and the No. 34 Conquest Racing Ferrari 296 of Albert Costa but both continued.