The team had a strong start to pre-season, but during last week's final test in Bahrain Jenson Button admitted the car was behind expectations in terms of speed.
Upgrades are planned for the early stages of the season, which should improve the pace of the car, but Boullier believes McLaren's testing focus on how best to run the car in race trim - and ensuring the car is user-friendly - will pay off.
"It's true that downforce on the car will bring pace, but driveability of the car and powertrain, and power unit management, is also going to give you pace, at least until everyone is up to speed," Boullier said.
"The other parameter is the fuel situation where you have to adjust settings and driving style to make sure that you match numbers.
"Bahrain is one of the toughest races in terms of fuel consumption, so you may have some cars doing race simulations but in full power mode.
"At the end of the run, you burn 110kg and you are outside [the rules] and that means in Melbourne you won't finish the race
"But you can easily see that Mercedes looks very fast, Red Bull looks very fast and for the others it's a bit more [difficult to say].
"Williams looks better than last year in the pecking order. We are not bad.
"We have obviously some advantage in the driveability of the car and we have a lot of different performance packages coming."
Boullier has no doubts that McLaren has moved forward from 2013, when it finished fifth in the constructors' championship and failed to claim a podium finish for the first time since 1980.
"There is a step forward," he said.
"They have considered what happened last year and have a better understanding about why they couldn't exploit the car as they wanted."
Boullier also downplayed fears that the imminent end of the Mercedes engine partnership, which started in 1995, would affect the team in 2014 even though the dynamic between the two sides has inevitably changed.
McLaren renews its alliance with Honda in 2015, leading to some speculation that its relationship with Mercedes could deteriorate.
"The relationship is very good," said Boullier.
"There is a shift in the relationship from partner to, let's say, more customer, so this is why some habits need to be changed."
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