Lewis Hamilton won the inaugural Russian Grand Prix on his way to clinching the Formula One drivers' championship last season and another victory in Sochi would further strengthen his defence of the title.

The Mercedes driver sits 48 points clear of team-mate Nico Rosberg after victory in Suzuka a fortnight ago, while Ferrari's Sebastian Vettel - third in that race - is a further 11 points adrift.

Rosberg insists that, with five races to go, he is "not backing down" in his quest to topple Hamilton in the standings, but this weekend's focus could shift momentarily to the constructors' championship.

Mercedes will be celebrating their second constructors' crown should they outscore Ferrari by three points in Russia, where they clinched their maiden title in 2014.

AROUND THE PADDOCK

It has been a busy couple of weeks in F1, with Jenson Button's decision to remain with McLaren for another season catching some off guard.

Renault confirmed their intention to buy a controlling stake in Lotus, who will lose Romain Grosjean to new team Haas ahead of the 2016 season, while Force India and Sauber registered a complaint with the European Commission over the "unfair and unlawful" governance of the sport.

Manor Marussia announced they would use Mercedes engines from next season and Toro Rosso's Max Verstappen passed his driving test – six months after making his F1 debut.

As if that was not enough, Bernie Ecclestone revealed this week that F1 could be sold by the end of the year.

PRE-RACE SOUNDBITES

Rosberg said: "We have five races to go and, although the championship gap to Lewis is quite big, in my mind it's definitely not over yet."

Hamilton, who attended Paris Fashion Week in recent days, added: "The car was unbelievable to drive in Japan, so hopefully it'll be more of the same at the remaining races – starting in Sochi. Last year was the first experience I'd had of Russia in my racing career and we had a great race there."

Discussing his decision to remain at McLaren for another season, Button commented: "I'm really pleased that my plans for next year have been confirmed – I'm fully committed to this team and have strong faith in the incredibly hard work that's going on behind the scenes in Woking and Sakura."

THE CIRCUIT

The Sochi Autodrom is one of the longest circuits on the F1 calendar and circumnavigates Sochi Olympic Park, which hosted the 2014 Winter Olympic Games.

The circuit includes a one-kilometre stretch of public road.

WEATHER FORECAST

Drivers may have to contend with changeable conditions in Russia this weekend, with rain looking likely for Friday's practice sessions.

Qualifying looks set to be a dry affair, but the threat of rain could well give teams and drivers a headache on Sunday.

GRAND PRIX GOLD

Hamilton dominated this race last year, topping qualifying before leading the throughout to seal an emphatic victory.