Rebellion Racing tests 2015 spec car ahead of its debut at Le Mans

The two revised R-Ones, which are powered by the twin-turbo V6 built by Advanced Engine Research in place of last year's Toyota normally-aspirated V8, undertook their first laps today at Paul Ricard with Mathias Beche, Dominik Kraihamer and Alexandre Imperatori driving.

Further testing of the ORECA-built LMP1 is planned tomorrow and again on Monday when Nick Heidfeld, Nicolas Prost and Daniel Abt, who are all racing in the Berlin Formula E event this weekend, will be present.

Rebellion team boss Bart Hayden told AUTOSPORT: "Today was always on the plan as our first test with the new package, so it is nice to make it and get out there.

"We are working through an expected list of things to do, but so far so good."

Hayden revealed that he is still hopeful of a good showing in the 24 Hours on June 13/14, despite the team having to miss the opening WEC rounds at Silverstone and Spa after a late decision on the replacement engine.

"We're not completely starting from scratch because we have a season's worth of experience with the car, albeit with a different engine," he explained.

"We are three or four steps ahead of that and we are reasonably optimistic, even though we know we have a big challenge ahead."

Rebellion's lead R-One finished fourth at Le Mans last year in the hands of Heidfeld, Beche and Prost, who also went on to win the WEC LMP1 privateers' title.