World Endurance Championship rivals Audi and Porsche have expressed satisfaction with major tests last week as they step up up their preparations for the 2016 season.
Audi was at Sebring in the USA for the first proper test of the all-new 2016 R18 e-tron quattro unveiled earlier this month, while Porsche tested a 2015 919 Hybrid with some of the developments planned for next season's uprated car at Aragon in Spain.
The multi-day test at Sebring, in which all six of Audi's regular drivers participated, was the first test of the new R18 since a shakedown at Paul Ricard in November.
Christopher Reinke, head of LMP at Audi Sport, said: "We have been able to gather a lot of findings
"The suspension, the chassis structure, and particularly the powertrain components, were subjected to an endurance test at Sebring.
"We checked off a large number of tasks on our list and are now going to tackle our next goals."
The updated 919 tested by Porsche in Spain incorporated revised front suspension and the complete 2016-specification engine and hybrid system.
Porsche LMP1 technical director Alex Hitzinger described the Aragon run as a "productive test in which we completed 6000km".