Cadillac DPi-V.Rs dominated the opening day of IMSA WeatherTech SportsCar Championship testing at Sebring, with Filipe Albuquerque leading the way for Action Express Racing.

Albuquerque reeled off a quick time of 1:49.759 midway through the afternoon session in his No. 5 Cadillac, outpacing the sister No. 31 entry of Dane Cameron by 0.317 seconds.

Cameron’s lap topped the time charts in the three-hour morning session and was one-tenth quicker than the Rolex 24 at Daytona-winning No. 10 Wayne Taylor Racing Cadillac of Jordan Taylor, which ended the day third.

The seven quickest times were all Cadillacs.

The No. 52 PR1/Mathiasen Motorsports Ligier JS P217 Gibson was the quickest non-Cadillac in fourth, thanks to Olivier Pla’s 1:51.313 time set in the morning.

Both of the Tequila Patron ESM Nissan Onroak DPis didn’t go out on the afternoon after undergoing engine changes, with Ryan Dalziel only able to muster a 1:52.010 lap prior to low pressure alarms on his No. 2 car.

The pair of Mazda RT24-Ps, meanwhile, were also lacking pace, with Jonathan Bomarito quickest out of the camp with a 1:51.868.

Ford ended the day 1-2 in GT Le Mans, with Daytona class winner Dirk Mueller leading the way with a 1:58.894, set in the afternoon session while the No. 54 CORE autosport Porsche 911 GT3 R paced GT Daytona in the hands of Colin Braun.

The No. 8 Starworks Motorsport Oreca FLM09 was quickest in Prototype Challenge, which features only two cars at this week’s test.

No major incidents were reported on Thursday, although there were multiple red flags, mainly for track inspection.

An additional eight hours of testing is on tap for Friday.

RESULTS: Test Session 1

RESULTS: Test Session 2