After Wednesday’s media day in the Circuit Ricardo Tormo, the Thursday period ran in a continuous six-hour period to complete the three-day track run.
Mortara, who finished just seven points away from champion Nyck de Vries last season, rose to the top of the leaderboard just after the middle of the session at 1m25,763.
This meant he finished the fourth quarter of a day ahead of the next fastest driver, Jean-Eric Vergne, while overtaking Robin Frijns and Antonio Felix da Costa on Monday and Tuesday at speed setting times – both high at 1 m26 per second.
Mortara remained in first place for most of the 2h30m, while Vergne’s 1m25.804s effort had been posted before the first hour of the session had elapsed.
Stoffel Vandoornen’s Mercedes ran third, while Jaguar Racing’s Kiwi charge Mitch Evans beat Porsche rival Pascal Wehrlein in fourth place.
Thanks to a cost-effective two-year type-approval period, last season’s transmissions have been postponed, with fears of reliability being low.
However, two red flags interrupted the game.
Oliver Askew, an American recruiter from Andretti Autosport, was the first to bother the race leader when he spun and landed on gravel in the 8th turn after just 15 minutes.
He was recovered by a tractor and dropped back on the asphalt to return to the depot before finishing the 17th fastest of the day.
Sergio Sette Camara, Dragon Penske Autosport, Penske EV-5
Photo: Carl Bingham / Motorsport Images
The second break came an hour later when Sergio Sette Camara’s only Dragon Penske Autosport machine stopped at turn 7. He finished 19th.
Nyck de Vries finished sixth on the timeline ahead of Envision Racing’s Nick Cassidy and Frijns duo, while Antonio Felix da Costa finished ninth on DS Techeetah.
Alexander Sims ran 10th in Mahindra Racing ahead of Sam Bird and Jake Dennis.
Adam Carroll, who made up half of the Jaguar lineup in its debut campaign 2016-2017, replaced Jeddah-based FIA Formula 2 driver Dan Ticktum at NIO 333 on the final day.
The team’s Irish deputy driver ran 21st out of 22 cars and made 1 m28,192 s best effort to track down his teammate Oliver Turvey in one place and 1.3 seconds.
However, the last car didn’t leave the garage all day because Dragon Penske Autosport seemed left unsure and couldn’t find a replacement for Antonio Giovinazz when the Italian flew to Saudi Arabia to compete in his second final Formula 1 race for Alfa Romeo.