Singapore presents special challenges - and they are pretty much the same each year: it's a race that's all about trying to maintain a good pace without losing your brakes or running out of fuel.
The fuel tank sizes - and thus the general dimensions of the cars - are based around the fuel usage at this race. The tanks hold around 160kg of fuel, and that's a marginal amount around here, especially if there is no safety car (though that has never happened in the previous four events here), and the engine's performance has to be monitored very carefully.
There is a similar challenge with the tyres - both in qualifying and the race, and that was very evident through the Friday practices.
Although Red Bull's Sebastian Vettel headed the low-fuel/option tyres qualifying simulations ahead of Jenson Button's McLaren and Fernando Alonso's Ferrari, the contrast in the way the Red Bull and McLaren laps were achieved was illuminating.
The super soft tyre cannot do a full lap around this place at qualifying pace; it's too soft a compound for such a long lap comprised of so many low gear acceleration zones. The driver is therefore faced with the choice of nailing the first two sectors and suffering the consequences of an overheated surface in the final one - or surrendering some time in the first sector in order to have the tyres still in shape at the end of the lap. The McLaren drivers took the former option, the Red Bull drivers the latter.
Which is better over a lap is something that will only be known once the teams have micro-analysed their data and it's quite possible there will be a convergence by the time of qualifying.
But there's a distinct possibility that the Red Bull method was better - in which case Vettel's 0.3-second margin over Button may be slightly flattering. Backing that up is the fact that on the harder prime tyre (the soft) Vettel trailed Lewis Hamilton's McLaren by 0.3s.
Regardless of that though, Red Bull appears to be back in the game after its iffy Monza form, where the Renault engine was not best suited to the track. Hamilton did his low-fuel run earlier than Button and ran wide at the final corner, so not too much should be read into his trailing 0.4s behind his team-mate.
Mark Webber has historically struggled to match Vettel around this track, especially in the short, sharp direction changes required for the final sector, though that 0.6s gap will surely be narrowed by qualifying.
Alonso's long-run pace was very promising © XPB
Alonso's qualifying simulation gave the third quickest time, the Ferrari a couple of tenths adrift of Button. But its long run pace might be formidable. Alonso's average long-run lap was a couple of tenths faster than anything from McLaren or Red Bull, but with the proviso that it wasn't as long.
Which brings us to the other key challenge of this race - namely whether any of the frontrunning cars can make a two-stop strategy work. Historically teams have tended to drift into a three-stop because tyre degradation has proved too high. But if anyone can keep their tyres in shape well enough to make a two-stop, there's a big potential gain to be made because the pit time loss here is the biggest of the season - it's a long pitlane and the speed limit is just 37.5mph.
Hamilton's rear super softs appeared to suffer a step drop after 10 laps. Which would leave the primes in the remaining two stints of a two-stop needing to do 25-26 laps without excessive heat degradation. That seems a tall order. The Ferrari and Red Bull tend to be slightly easier on the tyres than the McLaren and although there was no like-for-like comparison with Alonso, Vettel's pace did not appear to drop off as quickly as Hamilton's.
The downside of a two-stop - even if you can get the tyre life - is how vulnerable it could leave you at a safety car restart. The gamble is there for someone to try - but it may not be from the big three.
We've yet to mention Lotus. If Friday is any guide it was not quick in either qualifying or race simulation. Kimi Raikkonen began his super-soft long run trading times with Hamilton but the tyres appeared to degrade suddenly after just three fast laps.
But it at least looked in better shape than Mercedes, the team still tweaking its all-new 'Coanda' exhaust system and appearing to be solidly the third-fastest of the three Mercedes-powered teams.