After appearing to have podium-winning pace in China three weeks ago, Mercedes could be set to make another major step towards the front this weekend.
Bild newspaper reports that Nico Rosberg tried the W02 car's Istanbul upgrade in the Brackley simulator last week.
"In the simulator I was fast," the German confirmed.
Bild said the upgrade package could amount to as much as one second per lap in qualifying.
"We need to keep pushing to try to get closer to Red Bull," added Rosberg.