Gunther Steiner thinks Haas can do "a good job" once again in 2019.
In 2018, the new American team surprised in its second year on the grid by finishing fifth overall.
And boss Steiner thinks Haas can do it again.
"When I look at the numbers, I'm sure we will have a good car," he told the Danish newspaper Ekstra Bladet.
"But even last year I didn't say anything about how good the others would be. Because I don't know.
"We are happy with what we see, but considering the new rules, has anyone found something that we haven't? How can I know?" Steiner added.
However, Steiner said Haas' goal is to push again for fifth place in the constructors' standings behind the top three teams and the improving Renault.
"Everyone wants to go for that position or even better," he said.
"We have to do a good job over the winter, as we did last year, and make a good car. There are no secrets. Everyone is trying to get that position," said Steiner.
"If someone does a little bit more than us, they will be ahead and we have to live with that. And we will try to catch them again."