Haas' two race drivers are lobbying for the return of the team's Melbourne specification car.
The American team got off to a flying start in 2019, but more recently has struggled to make Pirelli's controversial tyres work.
Although his place at Haas is reportedly in danger, Romain Grosjean was behind the proposal to resurrect the Melbourne-spec car.
Indeed, at Hockenheim he is again driving the old car, which looks faster than the newer specification that is still being raced by Kevin Magnussen.
"The other car seems to be more stable, regardless of whether it is hot or cold," Magnussen told Ekstra Bladet newspaper.
"In the end it's not my decision. We need to do what's best for the team. But I don't hide that I would like to go back to the old car if I can.
"Why? Because it's faster. We just need to think about the long term," he added.