Two-time winner Jenson Button said on Thursday McLaren will introduce a new exhaust system into their cars for Sunday's Australian Grand Prix in a bid to stay with Red Bull and Ferrari.
The 31-year-old Briton revealed his team's planning after a troubled winter testing programme which left McLaren trailing the two hot shot teams heading into the Melbourne season opener.
And Button also predicted that the faster-degrading Pirelli tyres to be used by all teams this season may help McLaren in the final stages of Sunday's race on the abrasive Albert Park street circuit.
Button praised his team's aggressive approach to go after the points with the new exhaust design.
"We have a new exhaust system here," Button told reporters. "Winter testing was not easy for us, it was very tough and reliability was not as good as we would have hoped and we didn't do a lot of mileage.
"I don't think we could really see the pace of our cars and we knew we weren't as quick as the Red Bulls and the Ferraris, but we just don't know where we were.
"With the new exhaust system, if everything goes to plan and with a few other tweaks to the cars, we hopefully have made up quite a bit of ground."
Button, who beat Renault's Robert Kubica in last year's rain-disrupted race, supported his team's pro-active move.
"Whether it's enough to make up with the other teams we'll have to wait and see, but I like the aggressive approach of bringing another exhaust system here and really fighting for it," he said.
"The aggressive approach is a good approach and we've just got to hope that tomorrow is dry so we can do some set-up work with it, because the set-up work so far has been limited."
Button, who is about to drive in his 192nd GP this weekend, conceded that world constructors' champion Red Bull and 16-time champion team Ferrari were ahead of McLaren going into the first race.
"You would say that Ferrari and Red Bull have dominated winter testing in terms of their pace and reliability," he said.
"Those two teams are probably the happiest coming out of winter testing, so they've done everything that they wanted to.
"I just don't know where we are, we could be pleasantly surprised this weekend.
"Hopefully, reliability is not an issue any more, because we haven't done a lot of mileage in the car, and we've got to start working on our pace."
Button predicted that the new season regulations of using faster-wearing tyres will play a role in the latter stages of races which could feature up to four pit stops.
"The tyres are going to be interesting. We haven't raced them and it will be interesting to see how people do look after the tyres or do we take our brain out and go full speed ahead," he said.
"I think tyre degradation will work for us in the last stint. The first few stops are going to be happening quite early and the last stint is the one where I think you will need tyre management.
"I think you will see so much overtaking here in the last stint that it will shock everyone," he said.
"It's going to be until the last corner this race, which is great, because we don't understand the tyres yet."