Porsche led the way at the end of the first session of the official pre-season World Endurance Championship test at Paul Ricard.
Neel Jani topped the times with a 1m38.264s aboard the reworked version of last year's championship-winning 919 Hybrid.
Porsche and Audi were testing the high-downforce configurations that they will race in the Silverstone WEC opener on April 17, while Toyota was running its TS050 in low-downforce Le Mans trim.
Each of the manufacturers is running one car on each of the two days of the so-called 'prologue'.
The Porsche's time compares with the 1m37.220s with which Jani ended last year's WEC test at Ricard and follows moves to slow the LMP1 pack with a reduction in the per-lap fuel allocation.
The LMP2 times were led by the Signatech Alpine ORECA-Nissan 05 with a 1m47.340s from Nelson Panciatici, who was just over two tenths quicker than the team's sister entry in the hands of Gustavo Menezes.
The two factory AF Corse Ferrari 488 Italias were quickest in GTE Pro, Gianmaria Bruni edging out Sam Bird by four tenths.
Testing continues on Friday afternoon and Saturday.