Mercedes' rivals are in for some bad news -- the dominant German team looks set to pull even further ahead in Singapore and beyond.

Germany's Auto Motor und Sport reports that the Brackley team will correct its flawed gear ratio selection ahead of the night race in the Asian city-state next weekend.

The rules dictate that the gear ratios chosen by each competitor at the start of 2014 are then frozen for the entire year -- with the exception of one "joker".

Mercedes has now decided to make that "joker" ratio change for the rest of the season, beginning in Singapore.

Auto Motor und Sport reports that it was on the long straights at Monza last weekend that Lewis Hamilton and Nico Rosberg used eighth gear for the very first time.

"It (eighth gear) was too long for all the other circuits," admitted designer Aldo Costa.

Mercedes' miscalculation will now be corrected with a shorter eighth gear for Singapore and the subsequent decisive rounds of the world championship.

Curiously, the German marque's customer, the surprisingly competitive Williams, got its gear ratio calculation right from the very beginning in 2014.

But technical boss Pat Symonds admits: "We were a little nervous at first because we thought they (Mercedes) would know their engine inside out.

"After a few races I was reassured," he added.

Symonds said that even though the eighth gear was introduced this year especially for the new turbo V6 rules, in the end it was unnecessary.

"The engines have so much torque that we could make do with a five speed gearbox," he said. "It would save a lot of weight and space.

"Unfortunately, the regulations prescribe the eighth gear -- otherwise we would have never had it," said Symonds.

(GMM)