Singapore played host to what was by some margin Mercedes' worst performance of 2015, but, a year on, the German team seems to have recovered its form at the street circuit, with Nico Rosberg setting the best time of Friday practice.

Vettel, who had won the race last year, ended Friday in fifth, but is certain both his Ferrari team and his former team Red Bull have a chance at challenging Mercedes as the weekend progresses.

"Both [Mercedes and Red Bull] looked very strong," Vettel said. "I think Mercedes is the favourite, I think we're in the same boat as Red Bull.

"We'll try to get everything aligned, and then hopefully we'll get a shot at the first row."

Vettel ended FP2 a second off Rosberg, but was also more than seven tenths adrift of teammate Kimi Raikkonen.

"I wasn't entirely happy, struggling a bit with the car balance and therefore not really finding the rhythm," Vettel conceded.

"I think my lap wasn't good enough, I think he [Kimi] had a very good lap and felt good this evening."

"But all in all it's been a good day."

Despite severely outpacing his teammate, Raikkonen suggested his best lap in FP2 had come easy, and that he could've gone significantly quicker.

"We'll see tomorrow but it was quite an okay day," Raikkonen said.

"In second practice, the car was feeling quite good, the laptime was easy. Three tenths today we can find by just pushing a bit higher, but tomorrow is another day."