With the first track action for the 85th running of the Le Mans 24 Hours about to begin, Sam Smith and Jamie Klein pick out 10 themes to be on the lookout for this weekend.
Will Toyota continue to dominate the pace?
The test day pace shown by the Toyota TS050 Hybrids, particularly the Kamui Kobayashi-piloted #7 car, must have been a sobering moment for Porsche, especially as Kobayashi claims to have encountered a not insignificant amount of traffic on his best lap.
Toyota’s enhanced package this year is punchy and its 8MJ hybrid 2.4-litre twin-turbo V6 package looks to hold an advantage at this early stage.
The final qualifying outcome won’t be as stark or clear cut as the test day, but it is currently hard to see how the more slippery Toyotas can be beaten or even split by the Porsches in Wednesday and Thursday’s qualifying sessions.
With weather forecasts estimating temperatures of around 30 degrees this weekend, expect the extra variable of thermal management in the powertrains to become a potential race-defining topic.
Does Porsche have any aces up its sleeve?
Porsche seems not to be chasing any qualifying headlines this year. The Weissach concern has been focussing on race pace for the duration of its preparation with the now relatively elderly - in structure terms, at least - 919 Hybrid.
But only a fool would underestimate Porsche, which remains adamant it will be gunning for a 19th Le Mans victory. It has a stronger line-up of drivers in 2017, and on pitstops holds a small advantage thanks to a retained wheel-nut device and seemingly more efficient fuel application.
The bigger picture of course is that Timo Bernhard, Brendon Hartley and Earl Bamber sit just 17 points behind Buemi, Davidson and Nakajima in the FIA WEC standings.
With higher-downforce tracks coming up after Le Mans, even a damage limitation strategy this week, should it be needed, will keep them in touch for a potential WEC title hat-trick.
Will pole position time be fastest ever on current circuit configuration?
Kobayashi’s best effort of 3m18.132s during last weekend's test was 1.3s shy of Neel Jani’s 2015 pole setting time of 3m16.887s, which still stands as the quickest-ever lap of the current 8.469-mile Le Mans configuration. Can that be smashed by Toyota?
The conditions look to be the hottest for many years at the 24 Hours, which could stifle usurping Jani’s time. However, with further rubber being laid up to the final qualifying session on Thursday evening, there are some seasoned observers speculating that a 3m15s lap is not out of the question.
Will Toyota's driver swap pay dividends?
Jose Maria Lopez has endured a torrid start to his WEC career, with an accident in his only Toyota race start to date at Silverstone. This led to the Argentine WTCC champion missing the Spa weekend, and the knock-on effect was a switch with Le Mans veteran Stephane Sarrazin.
Thus means Lopez will race alongside Nicolas Lapierre and Yuji Kunimoto (like Lopez, a Le Mans rookie) in the #9 TS050 Hybrid.
Make no mistake, Lopez is an exceptional racing driver, but endurance racing rewards experience and it was a logical decision to make the change from Toyota’s point of view.
Sarrazin was possibly unlucky to get demoted from a full-time WEC role this season, and will have extra motivation allied to his impressive Le Mans pedigree to be a perfect 'plug and play' addition to the increasingly strong Kobayashi-Conway axis.
Can an LMP2 car finish on the podium?
The simple answer is: yes, one can. With just six LMP1 cars (and only five hybrids), it will not take a huge amount for an LMP2 car to be in contention to make what would be a historic appearance on the overall podium.
The complexities of the Hybrid LMP1 cars can provide nasty surprises for their teams at any moment and rule them out of contention in an instant.
However, there are reliability concerns too for the new generation of the LMP2 class, which have proven to be trickier to work on in some areas than the former iteration of cars.
But come 3pm on Sunday, it would not be out of the question to see a Rebellion, Signatech Alpine, Jota Sport, TDS or DragonSpeed-run car claim a well-deserved place amid its bigger LMP1 brothers.
Will the LMP2 cars cause traffic angst?
The feedback from drivers across the category board is mixed. Some say the extra pace of the LMP2 cars brings a more conclusive execution to lapping GT traffic, but the counter argument is that this kind of purgatory effect could contribute to misunderstandings between the prototypes.
This is because the LMP1 cars reach terminal velocity after their recuperated energy is discharged, particularly on the Mulsanne straight. The pace of the LMP2 cars is such that they catch their bigger brothers on the second phase of the straights.
Rebellion driver Nicolas Prost doesn’t believe it will pose a particular problem this year.
“For me the situation with the LMP1 cars is much better than last year, when they would overtake and get in front of us, but then we were quicker so we would almost have to overtake again or lift and it was a bit dangerous, which was not so nice,” he told Motorsport.com.
“This year, from what I have seen so far, they overtake us and when their boost cuts we really stabilise, so in terms of P1s the situation has improved I think.
"In terms of GTEs and other P2s it is a bit more complicated, because there is quite a lot of traffic this year. There are a lot of P2s on the entry list and a few competitors are not really at the right level, which could cause some problems with traffic."
Can ByKolles beat the LMP2s?
As the sole privateer LMP1 car in the field, the ByKolles squad will realistically find itself battling the 25-strong LMP2 field behind, rather than the five hybrid LMP1 cars ahead. The question is, can Oliver Webb, Dominik Kraihamer and Marco Bonanomi avoid the ignominy of ф finish behind the cars they should be, in theory, beating easily?
Last month's Spa WEC round was encouraging, as the #4 ENSO CLM P1/01 enjoyed a clean run to sixth overall, a lap ahead of the best of the LMP2s, despite being rather slower in the middle sector.
The straightline advantage ByKolles was expecting to enjoy at La Sarthe seemed to be almost non-existent during the test day, but Webb reckoned the team's theoretical best laptime (the total of its best sectors) was some 2.5s up on the quickest of the LMP2s.
As ever, the deciding factor is likely to be reliability, not exactly a strong suit of the Austrian squad in recent years. But the switch to Nissan power over the winter has made a big difference in that department, and barring mistakes by the drivers it's not impossible to imagine the team enjoying a race trouble-free enough to put it a lap or two clear of the P2 gaggle.
Who will win a finely poised GTE Pro war?
If last season’s LMGTE Pro bubbled up to a memorable if largely controversial finale, the 2017 edition promises to be a more level contest between the five prestige manufacturers.
The conditions could be brutally hot for the LMGTE cars and strategy will be crucial, particularly on the tyre front - something that Dunlop-shod Aston Martin could turn into an advantage as it readies its faithful Vantage V8 design.
Porsche is back with a full factory team and a pair of brand-new mid-engined 911 RSRs, and the Pratt & Miller-run Corvette Racing squad will also be looking to challenge for a ninth Le Mans class win after setting the pace on test day.
Again though, the second installment of the modern-day Ford v. Ferrari clash is likely to have all eyes upon it, and a war of words between the two marques has already started with Sam Bird’s open speculation on the Blue Oval’s test pace.
It is hoped that the battle between two of endurance racing’s most evocative brands is contained to the track and not beyond it this season.
Can Aston Martin earn redemption in GTE Am?
If the question of redemption catches all the headlines in LMP1 this year should Toyota finally take that elusive victory, equally the LMGTE Am class could have a romantic twist to it.
Two years ago, the Aston Martin of Pedro Lamy, Mathias Lauda and Paul Dalla Lana seemingly had the win bought and paid for, but within an hour of the flag their dreams ended in the barriers at the Ford chicane. The lost points had a major impact on the trio's challenge for the WEC title, which by rights they should have won easily.
After a win at the last WEC round in Spa, and цшер Dalla Lana now proving to be among the best bronze-categorised racers, the team starts as one of the favourites.
Competition is likely to come from predominantly from Porsche and Ferrari, with the Dempsey-Proton, Scuderia Corsa an JMW entries being arguably the pick of the bunch.
How will Le Mans' high-profile rookies fare?
Plenty of rookies make their debuts at the fearsome Circuit de la Sarthe year in, year out, but the 2017 crop contains a surprisingly number of high-profile drivers from various walks of motorsport.
Chief among these has to be six-time F1 grand prix winner Rubens Barrichello, who joins the Racing Team Nederland LMP2 team for his first crack at Le Mans at the grand old age of 45, joining Jan Lammers and Frits van Eerd in a trio with a combined age of 156.
Several rather more youthful Le Mans rookies with strong single-seater backgrounds will also be vying for LMP2 glory, most notably ex-Toro Rosso driver Jean-Eric Vergne (Manor), 2015 European F3 champion Felix Rosenqvist (DragonSpeed), and Renault F1 tester Sergey Sirotkin (SMP Racing).
Last but not least, another Brazilian veteran will be making his La Sarthe bow in the form of IndyCar ace Tony Kanaan, a last-minute stand-in for the injured Sebastien Bourdais at Ford Chip Ganassi Racing.
How the 42-year-old settles into life at the Blue Oval will be one of the more intriguing sub-plots of the GTE Pro category, especially as how he fares will determine whether Joey Hand and Dirk Muller are able to retain the class title they secured last year.