Haas team principal Guenther Steiner has revealed comfort is at the heart of why drivers Kevin Magnussen and Nico Hulkenberg will use different car packages throughout this weekend’s Las Vegas Grand Prix.

Haas introduced a number of updates ahead of the United States GP with the hope it would alleviate the severe tyre degradation issues encountered by the VF-23s when in traffic which often resulted in the cars plummeting down the order during a race after a solid qualifying performance.

On the surface, although Hulkenberg has performed reasonably over the past three races, the German driver will revert back to the older specification, whilst Magnussen will continue with the new one.

Suggested to Steiner that Hulkenberg’s feelings with the current car were different from the numbers being seen by the engineers, he said: “I wouldn’t say it’s different because the cars don’t differentiate a lot.

“It’s just one of these things. He feels more comfortable, and there’s not a lot we have to lose and not a lot of data available to say the other car is a lot better.

“He says ‘I feel more comfortable’ (with the older car), and strangely enough, Kevin says the complete opposite. Therefore, we decided to be practical about it, to give the best chance to the drivers to feel comfortable, and do the best job we can.”

Steiner has conceded to obviously feeling disappointed the new package has not worked as expected but with only two grands prix remaining, he is in a more comfortable position running two different cars compared to if it was the start of the season.

“There are always pros and cons to everything, but where we are now, at the end of the season, there is not a lot to choose from,” said Steiner.

“If this had happened at the second race, then you would need to make sure you go in one direction.

“After this race (Las Vegas), there’s only one more to go, so if one feels more comfortable, I go with that one.

“But I knew the numbers, that there would not be this big difference if the data didn’t change, and it didn’t, so I was always very careful.

“It’s disappointing, I’m not happy about it, but it didn’t come completely unexpected.”

With the changes made to the aerodynamics, the suspicion is the faults of the car are likely to be more mechanically related.

“It could be,” said Steiner. “For sure, there’s not only one thing, there’s not like a golden bullet here to say, ‘Oh, it’s just the aero’. It’s always a combination of things.

“There is a new suspension coming for next year, which is in the wind tunnel now, so we know what it looks like, and hopefully that helps us as well with the tyre degradation.”

Hulkenberg has pointed to the fact that “personal preference” has resulted in him reverting to the pre-USGP spec of car.

“We’ve had three races with the new package, and whilst there were maybe some small benefits, there were also some not-so-good aspects with it and it was not the step forward that we needed from a big update,” said Hulkenberg.

“I just felt a little bit more comfortable and confident with the old package, and I think with the two circuits we have left now, it favours that slightly more, hence that call.”

Magnussen claims there are positives and negatives with both cars, with the newer model having the edge on the older spec.

“I do feel it (the new package) is different,” said Magnussen. “We’ve lost a lot of grip in high-speed corners, there’s no doubt about that, and braking in a straight line is better with the old car.

“But then I feel like the characteristics (of the car) through the corners are better with the new package, which suits my driving style better. It seems a little more consistent, hence why I stuck with the new package.”

The issue for the team and the drivers, however, is that, according to Magnussen, the data being viewed “doesn’t fully make sense”.

He added: “It will be interesting to get a direct comparison on feeling and seeing who’s going faster, in which corners, and see how that adds up with the data we have on the cars.

“Maybe it will give a clearer picture, and I think we need that because the correlation is a bit off at the moment.”