McLaren-Honda is confident it will see the chequered flag in the season-opening Australian Grand Prix.
Together again after more than two decades, the British team and the returning Japanese manufacturer notably struggled in the opening winter test at Jerez.
McLaren engineer director Matt Morris admitted to Germany's Auto Motor und Sport that testing so far has obviously not been perfect.
"The number of laps and the performance was disappointing," he admitted, "but we were able to tick off some things on the programme that showed us that our new car is good."
Morris said the correlation between the wind tunnel and the track, as well as cooling, was spot on, "which is good news, as problems in that area cannot be easily solved".
However, other areas of the development programme have been delayed, Morris admitted.
"We have slowed the aero programme," he said. "It makes no sense to bring upgrades when you have a lack of kilometres on the basic package.
"The plan was to start the season where we left off in 2014. However, this will require a testing programme without any major incidents."
When asked if McLaren-Honda is instead hoping simply to see the chequered flag in Melbourne, Morris admitted: "I think that's realistic."