The works Ferrari WEC team and the FIA are at odds over the performance of the 488 GTE cars in qualifying in Shanghai, after the Italian marque claimed they were hit by overnight changes in Balance of Performance.
Having led the way in both Friday practice sessions, the AF Corse-run cars could do no better than fourth and sixth on the grid in the GTE-Pro class.
The lead car, the #51 of James Calado and Gianmaria Bruni, was 0.924s behind the polesitting #67 Ford GT, while the sister #71 machine of Sam Bird and Davide Rigon was a further half a second back.
After qualifying, Ferrari issued a press release saying the session took place "after yet another change in the BoP on the 488 GTE cars, which occurred before the morning free practice."
However, the FIA later clarified unequivocally there were no changes in Balance of Performance made overnight.
The governing body did, however, acknowledge a reduction in atmospheric boost pressure from 1018 millibar to 1010, owing to a change in ambient temperatures.
This would have also affected Ford, which run turbo engines like Ferrari.
It is understood the change, which is equivalent to losing around 1.5 horsepower, will be reversed for Sunday's race.
Ford "in another race to us"
Speaking before the FIA clarification, Calado said the Ford GTs were in a different league to the Ferraris, and that the Italian marque was at a loss to explain the situation.
“We don’t understand," the Briton told Motorsport.com. "We did everything we could to find three tenths [from yesterday]. But they found two seconds overnight, which is quite a big step.
"It’s hard to compete with the speed [the Fords] have. On pace alone it wouldn’t surprise me if they catch the LMP2s. They are in another race to us."