The FIA has declared the latest configuration of Mercedes’ 2018 car to be legal.
Brazil’s Globo reports from Austin that Ferrari had suspected a regulations breach and requested that changes be made to the Mercedes for what could be the title-deciding race.
"The stewards did not accept Ferrari’s arguments," correspondent Livio Oricchio reports.
Ferrari had reportedly questioned the legality of Mercedes’ new rear wheel, brake and suspension layout.
One argument had been that the holes in Mercedes’ new wheels were moveable aerodynamic devices, but Charlie Whiting reportedly ruled that they simply reduce temperatures.
Meanwhile, Sky Italia reports that Ferrari is making a last-minute effort to keep Sebastian Vettel’s championship alive.
Lewis Hamilton will be champion on Sunday if he wins and Vettel is not second, but Sky Italia reports that Ferrari has introduced an "aerodynamic package" for Austin designed to improve recent balance problems.
"This year it has become a mission impossible, but it’s not over and we say very clearly that we are not beaten in Austin yet," team boss Maurizio Arrivabene said this week.