Lewis Hamilton (middle) and Rosberg (right of Hamilton) Photo: CFP

Mercedes teammates Nico Rosberg and Lewis Hamilton renew their sometimes hostile rivalry on the floodlit streets of Singapore this weekend at a circuit where mistakes or collisions normally result in race retirement.

With six races remaining in the 19-round season, Germany's Rosberg leads Hamilton by 22 points but the momentum and crowd sentiment are on the Briton's side after he won in Monza a fortnight ago following his ruined Grand Prix in Belgium.

Hamilton failed to finish in Spa last month after an unnecessary collision with Rosberg but gained a modicum of revenge in Italy when the German relinquished first place to his teammate after cracking under pressure midway through the race.

Rosberg finished second in both races and was booed on the podium on each occasion for benefiting from his over-aggressive approach in Belgium but Mercedes will be hoping the pair can rein in their fighting instincts to avoid further mishaps.

Coded messages banned

Since Monza, however, Formula One has banned radio race assistance, including coded messages, so it will be interesting to see how the team can control their drivers on an unforgiving 23-turn layout in the heat and humidity of Singapore.

Mercedes, who have won all but three of the 13 races this season, are expected to dominate once again with Hamilton installed as a marginal favorite due to his better record on the Marina Bay Street Circuit, where he won in 2009.

"Despite the highs and lows, I'm still well and truly in the hunt for the championship and that is something that gives me huge motivation for the final six races - starting in Singapore," Hamilton said in a team release.

"It's a great place to begin the final flyaway phase of the season. The city is buzzing and the track is mega. It's a street circuit and I love street circuits."

The Briton was unfortunate not to win the inaugural race in 2008 and a mechanical failure when clear at the front denied him victory two years ago, while Rosberg can take heart from one of his earliest successes in F1 at the venue.

"I got my second ever podium here with P2 in 2008 and I generally enjoy street circuits, so I'm looking to go one better this time around," the German said.

Nico Rosberg leads the pack during the Italy Grand Prix on September 7. Photo: CFP

Second fiddle

World champion Sebastian Vettel has endured a miserable winless campaign but arrives in Singapore seeking a fourth straight victory in the race in an improving Red Bull that is expected to present the sternest opposition to Mercedes.

The German, however, has been forced to play second fiddle to teammate Daniel Ricciardo all season with the Australian winning three races, leading to whispers in the paddock that Vettel's future could lie away from Red Bull, with Ferrari a possible destination.

While Red Bull have moved quickly to quash any exit rumors, team principal Christian Horner was also keen to play down expectations of a return to the top of the tree for the reigning champions in Southeast Asia.

"At Singapore, there are a few more corners and a few less straights (than at Monza)," Horner said after his cars came fifth and sixth in Italy.

"We're looking forward to going back there.

"It's a track that we've always gone well at in the last few years. But there's no guarantees in this business, and we expect the Mercedes to be incredibly quick."

The Mercedes-powered Williams has been somewhat of a ­revelation this season with Valtteri Bottas ­claiming four podiums in the last six races while his teammate Felipe Massa enjoyed a third-place finish in Monza.

Another strong result is expected in Singapore but Bottas believes the car will find it difficult to compete for another podium finish with its aerodynamic efficiency less effective on the demanding and tight ­Singapore roads.

"Singapore, maybe Brazil, they could be difficult ones," the Finn said. "But we reckon there are some good ones to come.

"We are still aiming to bring some updates later in the season, so Suzuka, Austin and Abu Dhabi, for example, I think we can fight for the podium definitely. We'll keep ­pushing."

Kobayashi kept

Japanese F1 driver Kamui Kobayashi has kept his Caterham seat for Sunday's Singapore Grand Prix despite lingering uncertainty about his future at the struggling team.

The 28-year-old was dropped for German debutant Andre Lotterer at last month's Belgian Grand Prix but returned for the Italian round after a late call-up.

With his home Japanese Grand Prix following Singapore's night race, he can now expect to do at least the next two rounds.

Caterham named Kobayashi and Sweden's Marcus Ericsson in their preview for the race.