Honda is running behind schedule so far in 2016, McLaren team boss Eric Boullier has revealed.
McLaren had a poor 2015, finishing ninth in the constructors' standings.
When asked about the new MP4-31, Boullier told Auto Motor und Sport: "From the McLaren side we are on schedule. For the engine, not yet. But at Honda there are good signs of progress.
"We could at least start to develop the car in the second week of testing, which was not possible last year.
"The car is not yet where we want it. The engine has not yet reached the numbers that were planned for 2016."
The new season begins with the Australian Grand Prix next weekend.