It would be "idiotic" to predict a giant step forwards for Haas at the team's home race in Austin next weekend.
That is the warning of team racer Kevin Magnussen, who is nonetheless looking forward to the end of a long development delay for Haas at the US GP with the introduction of a B-spec car.
Haas is now second-to-last in the constructors' standings, with a car that often looked good over a single lap but faded fast with extreme tyre wear in the races.
It is now expected that Haas' B-car will follow the McLaren-like development trend with a basic aerodynamic concept that mirrors dominant Red Bull's.
"This specification of the car ended worse than it started, so we are happy to see the end of it," Haas team boss Gunther Steiner told Ekstra Bladet newspaper.
But while McLaren has made giant strides since beginning to develop the more Red Bull-like concept, Danish driver Magnussen is not expecting that.
"On paper we don't expect a huge increase in downforce," he said. "It's more of a different concept that works in a different way.
"We hope to find more stability and a stronger platform under different conditions.
"The car we have right now looks pretty good on paper, but on the track it's not that great," Magnussen explained. "We do expect progress, but the reality out on the field may be different.
"But if the new car is easier to drive, if it is fundamentally stronger, better in crosswinds, in dirty air and the like, it will perhaps also be better with the tyres," he said.
"It's like a chain reaction that affects many things. So we hope that it is a completely different story on the field than in theory. But it is idiotic to come out and say that we expect to take a giant leap forward with an upgrade that on paper does not look all that much better.
"We try to be humble," Magnussen explained, "take as much learning as possible, and then hope for the giant leap."
Haas is now basically alone among rival teams in unveiling a significant car upgrade so late in the 2023 season, but the small American team says it is laying down the foundation for next year.
"I think it's positive that we're throwing things at the car so late in the season," Magnussen said. "This year has not been written off.
"It's exciting for the remaining races, but also for the development of next year's car. In the end, it is also a research exercise, which provides answers and clues for next season."
Indeed, apart from preparing for the 2024 car, Ekstra Bladet believes that moving up from ninth to seventh overall in the constructors' championship could be worth millions to Haas in official prize money.
