Marcus Ericsson carries his weight in F1, but Sauber boss Fred Vasseur insists the Swede's natural ballast was detrimental to his performance last year.
The 27-year-old estimated that the 10kg weight difference between himself and 2017 team mate Pascal Wehrlein was worth a deficit of four tenths of a second a lap!
Factoring that handicap into Ericsson's performance last season, Vasseur believes his driver actually acquitted himself well against the highly rated Mercedes protégé who will be missing from the grid this year.
"I think if you look at Marcus last year, he improved a lot during the season," Vasseur told Racer's Chris Medland.
"We also have to be honest as a team that he was overweight. Mid-season he was more-or-less 10 kilos overweight. We were able to close the gap and come back to the limit in the last part of the season.
"In terms of performance he showed a good improvement and he did well compared to Pascal.
"From a team perspective and a team point of view, he has good experience, a good collaboration with the team and he's fully committed. It's also important for us to have a kind of stability and that experience."
Indeed, with Sauber running rookie Charles Leclerc this year, the Swiss outfit - and the young Monegasque - will need to rely on the Swede for guidance and experience.
"We know that Charles did a fantastic job in the junior series so far and he has impressive promise but he also has no experience of F1," adds Vasseur.
"He will have to discover perhaps 60 percent of the tracks and it was important for us to have a good reference with experience and already a good collaboration with the team.
"I think the line-up is quite balanced like this and we can expect a good collaboration from them and to get the best from them."