Romain Grosjean is hopeful that new parts for Haas' VF-16 will aid the Frenchman's feeling with the car, after complaints across the last two rounds.
Grosjean has scored points in three of this year's four Grands Prix but has been unhappy with the nature of the VF-16 since the Chinese Grand Prix.
"We've got new parts here that hopefully will improve my feeling," he said.
"It is very difficult to understand straight [away] if there is a problem on the car as all the tools we have are not yet 100 per cent calibrated.
"So we are trying now to get more knowledge and experience of everything.
"Hopefully tomorrow morning I am happy and get the feeling back from the beginning of the season."
Grosjean also spoke at the Spanish Grand Prix of his desire to participate in a NASCAR event, as Haas founder Gene Haas also co-owns a NASCAR operation.
"Definitely I want to do it, it's something we discussed since day one and it would be a great experience," he explained.
"With 21 races it's tight in Formula 1, of course you don't want to start on an oval, that wouldn't feel very comfortable."