The Formula One circus is this week in Singapore for round 15 of the season.
Lewis Hamilton holds a 63-point championship lead over Mercedes team-mate Valtteri Bottas with seven races remaining.
Here, the PA news agency takes a look at the key talking points ahead of Sunday's grand prix.
1. Hamilton bidding for Singapore hat-trick
Lewis Hamilton will go for his third straight win under the lights of the Marina Bay Street Circuit on Sunday – not a bad accomplishment given Mercedes' troubles at the slow-speed track in recent years. Sebastian Vettel's three-way pile up with Kimi Raikkonen and Max Verstappen cleared the way for Hamilton to win in 2017, before the Briton delivered the lap of his life in qualifying last year to take pole and the victory. Hamilton's Mercedes team are hopeful they have fixed the major flaws which has made the Singapore Grand Prix – despite Hamilton's impressive record – something of a bogey venue for them. Hamilton has arrived in the Far East following the launch of his latest fashion collection in Milan, and will know that another victory here could take him 70 points clear in the championship standings with just 150 remaining.
2. All eyes on Vettel as he treads penalty tightrope
23 corners x 61 laps = 1,403 turns 🤯
That's what @Charles_Leclerc and #Seb5 will be taking on during Sunday's race 🙌 #essereFerrari 🔴 pic.twitter.com/Ai3hKUf6O1
— Scuderia Ferrari (@ScuderiaFerrari) September 17, 2019
Vettel will be in the spotlight this week after his horror show in Monza last time out. The four-time world champion spun before collecting Lance Stroll. He finished 13th as Ferrari team-mate Charles Leclerc secured his second win in as many appearances. On a dire afternoon in front of the Ferrari hierarchy, Vettel was also hit with three points on his licence following the Stroll collision. Vettel, who has now failed to win a race in more than a year, is just one misdemeanour away from a race ban. The German will be desperate for a strong performance in Singapore, but the track, unlike the power-heavy Spa-Francorchamps and Monza layouts, is unlikely to suit his Ferrari machinery.
3. Red Bull to take fight to Mercedes
Indeed, it is Red Bull who are likely to be Mercedes' closest challengers this weekend. Verstappen headed into the summer break following a string of impressive performances, including triumphs in Austria and Germany. He was also within minutes of winning the Hungarian Grand Prix before Hamilton's impressive late fightback. But two first-lap incidents in his last two outings has seen the Dutchman drop 99 points behind Hamilton and just three in front of Leclerc. Verstappen will expect to be back among the frontrunners in Singapore though with the twisty track less dependent on engine grunt.
4. Contingency plan in place for haze
For next 24hrs, 1hr PM2.5 to range between Normal & Elevated bands. 24hr PSI to be in the high end of the Moderate and low end of Unhealthy ranges and may even enter mid Unhealthy. For next few days, SG may continue to experience hazy conditions. https://t.co/8TKqSFblvW
— NEA (@NEAsg) September 18, 2019
The air quality in Singapore continued to deteriorate on Wednesday with a visible haze – caused by forest fires in neighbouring Indonesia – hanging over the street circuit. Formula One bosses are confident the weekend's race will go off without a hitch, but the issue threatens to cast a cloud over proceedings. The Singapore National Environment Agency has urged for a second consecutive day for people to "reduce prolonged or strenuous outdoor physical exertion".
5. Drivers facing extreme physical test
The drivers will be tested to breaking point this weekend with the Singapore race the most demanding on the calendar. A combination of the humid climate, 23 corners around a street track where mistakes do not go unpunished, and a race lasting almost two hours, ensures that Hamilton and Co will earn their money on Sunday.
