LONDON - Haas will again run different aerodynamic configurations on their Formula One cars at this weekend's German Grand Prix as they try to turn around a season that has stalled after a strong start.

The U.S.-owned Formula One team have failed to score a point since Monaco in May, a run of four blanks in a row, and have plunged to ninth out of 10 in the standings at the midway point in the season.

Haas took sixth place with Danish driver Kevin Magnussen in Australia in March when they were best of the rest after Mercedes, Ferrari and Red Bull.

They have since failed to turn qualifying speed into race pace, and struggled to get performance out of the tyres.

Magnussen's car at Hockenheim will have fresh upgrades designed to improve downforce and driveability while French team mate Romain Grosjean's car will be as it was in Melbourne.

Haas, whose livery remains unchanged despite uncertainty over title sponsor Rich Energy, ran a similar aero split at Silverstone this month.

"We decided on this exercise to get data and understand better what the difference between the two cars is, good or bad, then we can see where we can make improvements," said team principal Guenther Steiner.

"We weren’t sure if the update we introduced in Barcelona was better or not.

"We’re running this again in Hockenheim, which is a different type of track with different temperatures -- they’ll be a lot higher -- and, as we all know, we couldn’t get a lot of data from the race at Silverstone from either of the cars."

The Haas cars collided on the first lap of the British Grand Prix, suffering punctures and retiring soon after.

"We need to get the understanding of where we are and where we didn’t work in the right direction. That’s the thing we have to do," said Steiner.

Grosjean said the upgrade introduced in Barcelona in May had felt wrong from the start, and he had wanted to revert back even then to the launch package which had less downforce but more stability.

The Frenchman was sixth last year in Germany.

"For me, the feeling was not so good from the rear end, especially through medium- and high-speed corners. The feeling hasn’t been good in those corners since then," he said.

"Going back to the Melbourne package, the car felt a lot better in those regions. It shows that something was not working as expected."

(Reporting by Alan Baldwin, editing by Pritha Sarkar) ((alan.baldwin@thomsonreuters.com; +442075427933; Reuters Messaging: Reuters Messaging: alan.baldwin.reuters.com@thomsonreuters.net))