Mercedes' Niki Lauda says the aerodynamics of its W08 Silver Arrows played a fundamental part in the car's 'diva' behaviour this year.
Mercedes suffered from performance swings, mainly in the first half of the season, which impacted its results and enabled rival Ferrari to gain an upper hand.
The team's W08 appeared to be the class of the field on fast tracks such as Silverstone or Monza, but tighter circuits such as Monaco or Hungary underlined the car's temperamental behaviour, prompting many to suggest its longer than average wheelbase was perhaps the root cause for its inconsistent performance.
"The length was never a problem. It was aerodynamics," Mercedes non-executive chairman Niki Lauda told Italy's Gazzetta dello Sport.
"There have been times when the car behaved in a fantastic way, and other times not.
"We have not yet fully understood it and that is what we have to correct for 2018. The rules are not changing so, having a good starting point, it will be easier to solve certain troubles."
While the German squad and Lewis Hamilton prevailed in the end against the Scuderia and Sebastian Vettel, with the Briton clinching the title in Mexico, Mercedes boss Toto Wolff echoed Lauda's comments.
But Wolff also said that Mercedes' 2018 design efforts, which are well underway, have been focused on preserving the qualities and ironing out the weaknesses of the W08.
"We don't believe that any of the characteristics on the more difficult days have anything to do with the longer wheelbase. We see with the Red Bull and Ferraris that they have good days and bad days.
"We would like to keep the characteristics of the diva that we like, but getting rid a little bit of the difficulties," he said.
"What you can see through the grid is that many people struggle in understanding why the car functions one day and not the other. We've seen it with our competitors as well.
"So, there is a car development process now to identify the root causes of why we struggle and try to avoid it with next year's car. Obviously we are quite far down the process of designing the car."