Nissan’s radical GT-R LM NISMO has been labelled as both “exciting” and “brave” by its opposition in this year’s World Endurance Championship.

The technical bosses of the Audi, Porsche and Toyota LMP1 programmes have all now expressed a first opinion on the front-engined, front-wheel-drive Nissan to AUTOSPORT.

Audi head of LMP1 Christopher Reinke said: “We were excited to see three very different concepts last season and to see a fourth even more different concept is even more exciting.

“We respect them for taking such a brave approach and it would be awesome if they are up there this season.”

Porsche LMP1 technical director Alex Hitzinger described the Nissan as “brave and risky”.

“The concept has very big disadvantages and it is not possible from sitting at a desk looking at pictures to judge if the potential advantages will over compensate for those disadvantages,” he stated.

One of those, he explained, was the decision to run narrow nine-inch tyres at the rear rather than the maximum 14in of its rivals.

“If you run a much narrower tyre at the rear than at the front, you are sacrificing tyre potential,” he said.

Toyota Motorsport technical director Pascal Vasselon expressed a similar opinion.

“Racing is about compromises: you gain in some areas and lose in others, so we will have to see if their concept works,” he said.

But Vasselon warned that he wasn’t writing off Nissan’s chances in the 2015: “One thing you learn in motor racing is humility and never to underestimate the competition.”

The radical concept of the GT-R LM, Nissan’s first contender for outright honours at the Le Mans 24 Hours since 1999, is an attempt to exploit the aerodynamic freedoms allowed at the front of the car in the P1 rulebook.

The front location of the engine has allowed Nissan to channel air in what GT-R LM technical director Ben Bowlby calls “through ducts” along the sides of the monocoque and out the back of the car for aerodynamic gain.