Karthikeyan seventh fastest in test session

The Hispania team did two runs in the morning session -- with intermediate tyres and soft tyres -- due to changing weather conditions.

Karthikeyan, who returned as F1 driver after nearly six years when he signed with Hispania, said it was a tough session due to adverse weather conditions.

"The weather conditions today were unfortunate as the track was pretty damp in the morning. We also had some trouble with the gearbox so we lost a bit of time before getting out on track. Towards the end of the morning, the track was pretty greasy so there wasn't much grip," Karthikeyan said.

"But the car has improved a lot, there is much more front grip. Tonio's feedback has definitely helped the front end of the car and we were able to clock a pretty decent time in the end," the Indian added.