Kevin Magnussen admits Haas, likely to finish the season dead last, has become lost amid its efforts to drastically improve its Formula 1 car.
In Las Vegas, the small American team took the unusual decision to take the 'old' 2023 car for Nico Hulkenberg, while Magnussen remains at the wheel of the troubled new 'B' machine.
"It's been a rough process with that upgrade," Magnussen told Ekstra Bladet newspaper.
"Part of our problem right now is that the data we collect from the aerodynamics in particular does not make any sense," the Danish driver added.
He therefore said comparing the old car with the 'B' car in Las Vegas will be "interesting" in terms of making better sense of the data.
"Maybe it gives us a clearer picture, which we need," said Magnussen. "It will be good to have both cars on the track at the same time, so we can compare."
Apart from that, the 31-year-old says he doesn't want to comment further on just how deep Haas' new technical crisis is.
"It is always difficult to go into too much detail or publicly say exactly what is happening, but yes, (data) correlation is a challenge," said Magnussen.
The team had hoped that emulating the Red Bull car concept would solve Haas' problem with extreme tyre wear. Part of the problem could be that the new concept clashes with the Ferrari-supplied suspension.
Team boss Gunther Steiner said in Las Vegas: "We have received the suspension from Ferrari for next season now and we are working with it in the wind tunnel."
Magnussen hopes that will make the new concept better for 2024, because at present "We have lost some grip in high speed corners. There's no doubt about it".
"And in a straight line, the deceleration is better in the old one. But I think the characteristics of the car are better with the new package," he insisted.
"It definitely suits my driving style better. That's why I'm hanging on to the new one."