Toro Rosso will be rolling out an upgrade to their aerodynamic package this weekend at the Circuit of the Americas in Austin, Texas.
But only one of their drivers will get a chance to try out the new components, with Pierre Gasly getting the nod over Brendon Hartley.
Gasly will try out the upgrades in Free Practice on Friday to see whether they deliver the sort of improvements that the team is hoping for. The team will then decide whether they stay on the STR13 for Saturday and Sunday.
The team has been searching for extra performance ever since the latest specification of Honda engine failed to deliver the leap forward in terms of power that had been hoped for. A successful qualifying in Suzuka suggested that they were now making headway.
Even so, Gasly admitted that Toro Rosso hadn't been keeping pace with its rivals when it came to car development as a whole in 2018.
"We haven't had new parts on the car for a long time and the team have been working hard in the last few months," he said. "Especially since the upgrade in Austria that didn't work.
"They have changed the whole process and way of working," he continued. "Now we are in a pretty good situation with the engine upgrades, the chassis upgrades.
"We saw the performance we managed to do when we extracted the full potential out of the car in Suzuka we know we can be in the fight there.
"Now it's about finding a bit more consistency from one track to another," he noted. "Hopefully with the upgrade it will give us a bit more consistency with performance."
Battling to maintain his seat at the team next season, Brendon Hartley was understandably disappointed not to have a chance to run the latest aero upgrades this weekend.
However he will be an interested onlooker to how Gasly fares this afternoon, and whether or not the new components make the grade to stay on his team mate's car for the whole of the weekend.
"It's yet to be decided, to be honest," Hartley said. "Obviously they have to make sure it works.
"It's a big one, there's a lot of new parts on the car," he added. "[We are] just trying to rectify all the issues we've had all year - if it works, it's exciting for the rest of the season."
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