Mercedes has admitted that reducing the weight of its 2017 Formula 1 car is an area that needs work as it reacts to its Australian Grand Prix defeat.
Although the W08's tyre usage was singled out by Lewis Hamilton as the key factor in Sebastian Vettel and Ferrari beating him to Melbourne victory, an issue with the with the Mercedes' weight has also come to light.
With components having been bulked up this year because of the extra forces coming from the higher cornering speeds, plus engine parts being more robust now that there are only four power units for the season, the weight of the Mercedes is understood to have crept over the 728kg minimum limit.
The extra weight not only costs lap time, but teams prefer to aim under the minimum weight restriction with their basic car so that they can then position ballast in the right places to help with handling.
Mercedes boss Toto Wolff would not confirm a report from Auto Motor Und Sport that the W08 was 5kg over the 728kg target, but conceded efforts were being made to bring the weight down.
"I don't want to go too much into detail but it's an area we can definitely improve," said Wolff.
"With new regulations and the size of the cars, you need to balance out all the time between performance parts and the weight.
"And that's an ongoing exercise which we are doing."
Mercedes is not the only team that is facing headaches regarding weight.
Red Bull is understood to have found itself right at the weight limit thanks to the extra 5kg it has had to carry with Renault reverting to its 2016 MGU-K for the start of the campaign.
One of the reasons why Red Bull did not pursue a more complex suspension system after the FIA clampdown was because the weight of the design had started creeping up.
Force India too had big concerns about the weight of its car - ordering its drivers to go on diets after testing to help - but thinks it can address matters by the Bahrain Grand Prix.
Deputy team principal Bob Fernley told Autosport: "We're already OK from a weight point. We're actually underweight but we're not enough underweight, so by Bahrain we will have enough of a variance there to be able to get the ballast where we want it. It's only a ballast issue."