Grosjean has had a nightmare season, scoring only two points through two P10 finishes at consecutive races in Spain and Monaco. His and Haas' poor form has led to rumours he could be replaced, with Esteban Ocon a potential replacement.
At the last race at Silverstone, the Frenchman reverted back to the setup he used in Melbourne and he has revealed it was a tough decision but reflected on it positively.
“It was a good test to do. It was a tough call from the team, but a good test," said Grosjean.
"When we brought the upgrade in Barcelona, I wanted to revert back on the Friday evening. For me, the feeling was not so good from the rear end, especially through medium- and high-speed corners. The feeling hasn’t been good in those corners since then.
Going back to the Melbourne package, the car felt a lot better in those regions.
"Now the aero guys are looking into it, but we know it’s been our weakness. Obviously, that launch package has some limitations also. It has less downforce, but it has better stability.”