McLaren trialled upgrades intended for the British Grand Prix at the Idiada test facility in Spain on Tuesday.
The squad allocated one of its straightline/constant radius days for this test, putting Briton Oliver Turvey in the driving seat, with the results intended to dictate which parts will be used in Friday practice at Silverstone.
Early indications are the new parts have performed well, and it is hoped that this will allow McLaren to make up for some of the downforce deficit to the likes of Red Bull and Ferrari.
"The only issue with our car is we lack downforce and that is what we are trying to create at the moment," said McLaren managing director Jonathan Neale.
"We are in Idiada at the moment. I spoke to the guys at lunchtime today, the weather has been kind to us and it looked set for a productive afternoon.
"But we are not there just for testing parts, we are there testing some fundamental understanding issues as well.
"We will wait until Friday afternoon at Silverstone to see what remains on the car for Saturday as to how successful it has been.
"We won't know until this evening finally what package we are going to take [to the British GP]."
Neale insists McLaren remain committed to working on its current car, though the new tests is expected to influence the design of the 2014 car as well.
"In terms of this year's car versus next year's car, we are still learning a lot," said Neale.
"There are some programmes on the car that we will want to run through until much later into the season which is important for next year as well.
"There isn't going to be a golden bullet. We are pushing hard but the reality of the situation is there is still a big gap from us to the front of the grid."
Neale is hopeful of McLaren running in the top 10 at Silverstone this weekend, though he admits a podium finish is a longshot.
"We want to get both cars into Q3 and then race hard for good points," he said.
"It would be great if the guys could get a podium out of it but I think on recent performance that could be quite challenging.
"But F1 is a fickle sport and you never know what is going to happen until the last lap."