Honda boss Yusuke Hasegawa has admitted that he is worried about the manufacturers reliability prospects for the upcoming season. He confirmed that the team still are unaware what caused the engine failure during the test.
"The mechanical issue, I don't know enough yet to be confident about that. Of course I worry about that," he said.
This issue was first of many that caused the team to use five different engines over the four days of testing. Last year, teams were permitted to use five engines over the course of a whole season.
On the second day of testing, a third engine was put in the car, but failed after 29 laps, and engine number four was placed in the car, which allowed Stoffel Vandoorne to complete 40 laps.
Wednesday and Thursday were more comfortable for McLaren, but a fifth engine change found its way in during that time. Asked whether the problems had affected Honda's relationship with McLaren, Hasegawa said that is has.
"In the tests, of course, this is a stage we need to overcome a lot of trouble. So sometimes we need to argue or we need to have constructive discussion, but I think we are doing a very good job and we have a very good relationship."
"We have modified the package so the engine is lighter and the centre of gravity lower," he said. "This gives us a big benefit of the behaviour of the car and we change the internal combustion engine to extract more power."