Eric Boullier expects McLaren to make big strides in the new Formula One season and banish memories of a disappointing 2015.
After years of challenging for the constructors' title, McLaren found themselves languishing at the back of the grid and battling with their Honda power units throughout last season.
Drivers Fernando Alonso and Jenson Button scored just 27 points across 19 grands prix, with McLaren finishing ninth out of 10 teams in the constructors' standings.
McLaren and Honda have worked hard since the last race in Abu Dhabi to make their 2016 car more competitive, and racing director Bouiller believes they have been successful.
"We are making big improvements and making massive progress," he told the official F1 website. "And there will be massive progress this year.
"The fact that there is more freedom for the engine manufacturers will have an impact, as you are able to change your targets and your timing.
"As far as McLaren is concerned we've been working very hard on the huge evolution of the car. We left no stone unturned.
"The car from last year has been really stripped down to details and we've tried to correct any weaknesses and it looks positive on the first test analysis. We have really improved the car.
"[But] I definitely don't want to build any wrong expectations - that would be wrong for everybody, including the drivers."