Porsche continued its test programme at the Sakhir circuit this week, completing over 3,000 miles of running with the new-look second generation 919 Hybrid.
It was the second meaningful test for the significantly-developed LMP1 racer after a test at Yas Marina last month.
Romain Dumas, Brendon Hartley, Nico Hulkenberg, Marc Lieb and Mark Webber were all on hand at the test, which the team's technical director Alex Hitzinger described as "encouraging, but not meaningful enough yet.
"Another positive thing is that the five drivers testing in Bahrain agreed with the four from the Abu Dhabi test that the driveability of the 2015 car is better than last year.
"This was one of our development targets."
The bulk of the running in Bahrain was believed to centre on Michelin tyre testing and aero evaluation.
The new frontal shape of the 2015 919 Hybrid is being developed with the aim of making the balance of the car more consistent and managing tyre degradation better, something which last year's car suffered due to the lack of tyre testing in 2013 when vibration issues around the engine installation lost precious testing time.
The new 919 Hybrid features a fresh monocoque design with a significantly enhanced vehicle dynamic package.
Porsche will continue to run a front-axle kinetic and exhaust-gas retrieval system in 2015 but what is still to be determined is whether it will elect to enhance the energy retrieval and move from the six megajoule class to the higher 8MJ division in 2015.
Motorsport.com understand this decision has already been made internally and is expected to be announced next month after the 2015 car is homologated.