Mercedes is set to abandon its Coanda-effect exhaust for the final race of the season in a bid to try and get a better understanding of its tyre situation.
After Nico Rosberg reverted to the non-Coanda design in Austin to assist the team's 2013 development programme, the team has elected to switch both its drivers to the old version for the final weekend of the season.
Mercedes motorsport boss Norbert Haug explained that the team felt its testing of Pirelli's 2013 rubber, which is being undertaken on Friday, would be aided if the team was running the standard exhausts.
"We are definitely starting without [the Coanda exhausts]," said Haug when asked by AUTOSPORT about the plans for this weekend.
"We want to start the tyre tests without any influence. We have proper data that we can compare with what we had at the start of the year, and then we will probably leave it like that."
Haug added that the way the Coanda exhausts were impacting on tyre temperatures left the team feeling that it would gain more running without them.
"We think it still has an influence on heating the tyres," he said. "There is also a little bit of a lack of aero downforce which we could not improve compared to the others.
"We think we will have a more realistic base to what we had at the beginning of the season and we work from there. But it is very clear that you have to have Coanda next year, because it gives you a benefit."
When asked if there were any plans for the team to switch back to the Coanda exhausts for Saturday, Haug said: "Not currently, no."