Toyota was never the favourite for this, the 90th anniversary running of the Le Mans 24 Hours. Yet the Japanese manufacturer's form over the second half of last year's World Endurance Championship suggested it would be more than capable of taking the fight to Audi in 2013. The results of the first two rounds of this season's world series and the Le Mans test day appear to suggest otherwise. At least in the collective mind of the Toyota Motorsport GmbH squad.
The upbeat mood in the Toyota camp on the launch of the second iteration of the TS030 HYBRID in February has changed. The smiles disappeared after the Silverstone WEC opener in April and turned to frowns post-Spa in May. Toyota's petrol-powered LMP1 coupes were beaten hands down by the new version of the Audi R18 e-tron quattro in both events and again lagged behind all three of the German cars at the test day earlier this month.
TMG technical director Pascal Vasselon was happy to describe Toyota as "pushy challengers" ahead of the start of the season. Now, he is all but suggesting that his cars will barely be in the game. "As it is, our chances at Le Mans are very, very small," he said in the wake of the Spa 6 Hours in May.
There was no softening of that attitude and certainly no fighting talk after the test day.
A significant increase in the horsepower Audi has attained — or chosen to attain — from its 3.7-litre turbodiesel V6 lies behind the dramatic shift in Toyota's view of its own chances in the 24 Hours this weekend. There can be no argument that the latest version of the single-turbo engine has more power than its 2012 iteration, because R18 hybrids are going fewer laps on a tankful of diesel.
The fuel-economy advantage enjoyed by Audi during last season has disappeared, so much so that the Toyota now goes further between refuelling stops. The fuel-consumption difference between 2012 and 2013 for Audi is approaching 20 per cent and Toyota estimates that its rival now enjoys a power advantage in the region of 80bhp, though it should be pointed out that it put the deficit at as much as 60bhp last year.
Toyota argues that Audi has used the freedom it enjoys with diesel to simply pump more fuel into the cylinders to gain more horsepower. This is something that Audi even admits, saying that the three per cent reduction in air-restrictor size for 2013 has forced it down a new route and resulted in a dramatic change in the way it maps the engine that forsakes economy.
Vasselon's argument is that the Automobile Club de l'Ouest and the FIA, which jointly write the LMP1 regulations, missed a trick in their continuing drive to balance turbodiesel and petrol-engine technologies over the winter.
Audi has lost the fuel-economy advantage © XPB
"What was wrong last year was to concentrate only on the power side and leave the fuel," he says. "If we leave one of the two open, then diesel technology can exploit this."
The Frenchman also points out that the technology of turbodiesel racing engines is in its relative infancy and there are still big gains to be made. Those involved in Peugeot's 908 programme of 2007-11 will now tell you that a large chunk of power, more than enough to make up for any changes in restrictor size or boost levels, was found by its engineers each winter.
Toyota went on the offensive after Spa, arguing for changes to the so-called Balance of Performance ahead of the race at Le Mans. The ACO reacted and, at the end of May, allowed the petrol-powered - privateer non-hybrids included - larger-capacity fuel tanks to the tune of three litres.
Toyota hasn't said anything meaningful about the late rule change, apart from issuing a brief statement:
"Toyota Racing acknowledges the statement issued today by the ACO regarding the balance of engine technologies in the World Endurance Championship and Le Mans 24 Hours," it read. "Toyota Racing trusts in the ACO's processes and its balance of technology principles."
The subtext is that those extra three litres of fuel capacity will be of little or no benefit to Toyota at Le Mans, though in the six-hour WEC races it could have an effect. Three litres of petrol doesn't equate to an extra lap of the 8.47-mile Circuit de la Sarthe.
Yet Toyota will have the upper hand in the economy stakes at Le Mans, which could prove important over the course of the 24 Hours.
The two additional laps of Spa that the Toyota managed between pitstops in comparison with the Audi should add up to a full lap at Le Mans.
Yet Audi reckons that fuel-economy advantage could prove significant.
"If they go one lap longer, then we have to go five or six tenths quicker a lap to make up for that," says Oliver Jarvis, who shares the #3 Audi with Lucas di Grassi and Marc Gene. "If they go two laps longer, that's 1.2 seconds."
Both cars have significant changes for this year
Audi and Toyota return to Le Mans with effectively the same design they each raced in 2012, but both have undertaken significant development programmes over the winter. Audi Sport boss Wolfgang Ullrich talks about "a nose to tail" review of last year's R18, while TMG LMP design leader John Litjens has used the phrase "evolution rather than revolution" when talking about the new TS030.
Audi has followed Toyota's lead by adopting the controversial rear wheelarch extensions that first ran on the TS030 at Silverstone last year. It has also had the resources available to develop a bespoke aero package for Le Mans in the form of the long-tail R18. That wasn't possible last year when Audi undertook an expensive hedge-betting exercise by developing a non-hybrid version of the R18, the ultra, to run alongside the e-tron quattro.
Drawing comparisons between the two 2013 Le Mans cars is difficult. Audi entered a single long-tail at Spa as a try-out for Le Mans, while Toyota brought only one new car to the Belgian WEC round on what was the debut of the latest TS030.
Audi chose to pile as much downforce on the long-tail at Spa in what was effectively a wet-weather Le Mans aero set-up, while Toyota was unable - or chose not - to run so much downforce. That explains why the Toyota struggled through the middle sector that includes the fast Pouhon double lefthander.
The test day proved equally inconclusive. The circuit was only dry for the final 90 minutes or so, while the time-topping #2 Audi was the only manufacturer LMP1 entry to undertake a qualifying simulation. Loic Duval ended up five seconds quicker than the best Toyota time set by Stephane Sarrazin, but he was nearly three seconds ahead of the second-best Audi in the hands of di Grassi.
THE HYBRID EFFECT
Not even Audi will dispute that Toyota's rear-wheel energy-retrieval system and supercapacitor were superior to its own flywheel set-up driven from the front axle. The controversial '120 Rule', which prevents the hybrid kick being deployed before a car equipped with front-axle energy retrieval reaches 120km/h or 75mph, hurt the German manufacturer. Yet its system is also less efficient in terms of the energy it could recuperate and return to the track.
Audi admits that it couldn't always harvest the 500kJ worth of energy it is allowed to discharge in each of the designated zones. That has been addressed for 2013, according to Ullrich.
"We pushed as much as possible to improve the system," he says. "If you do a whole season of racing you learn more than you do just testing. The difference has been made in how much [energy] can be recuperated and how fast we can bring it back onto the front axle."
The '120 Rule' probably means that Toyota can still benefit more from its hybrid punch, but it's less of a factor at Le Mans than at other circuits because their are fewer slow corners.
Audi has the upper hand in terms of reliability © LAT
Toyota's insistence that it couldn't be the favourite for Le Mans ahead of the start of the season was based on two facts: Audi's amazing record at the 24 Hours; and its own failure to complete the race last year or any of its pre-race endurance simulations.
Whether a TS030 has come through any of its four Le Mans simulations, which were completed at MotorLand Aragon in Spain at the end of May, without problems isn't entirely clear. Toyota will only say that any problems encountered weren't "car stoppers".
Anthony Davidson, who drives the #8 Toyota with Stephane Sarrazin and Sebastien Buemi, has been a little more expansive on the subject.
"Have we completed one of the simulations? The simple answer is no, but it is really much more complex than a yes or no answer," he says. "When you go endurance testing you run components out of life to see when they are going to break."
The new Toyota has so far retired from its only race so far, though the company seems unconcerned. The failure of its energy-retrieval system, which stopped harvesting and caused the brakes to overheat, resulted from connector failure traced to a faulty batch of parts.
Audi is the master of the mid-race repair. It raised the bar for serviceability upon entering the international sportscar arena in 1999. Think back to Allan McNish's crash at the Porsche Curves in 2004. Car and driver were able to crab back to the pits, but only one of them returned to the race, and that was the Audi R8. The prowess in the pits of Audi and its Joest team even resulted in a rule change: those complete rear-end changes of gearbox, suspension and ancillaries are now long since a thing of the past.
Toyota wasn't in the same league on its return to Le Mans last year. Remember the alternator failure that resulted in a 25-lap stay in the pits for the #7 car. It has, however, taken strides to up its game in this respect for 2013.
"We have worked in this area, for sure, because every second you gain in a repair situation is vital," says Vasselon. "We have taken a good step towards Audi, but I would not say we are quite so extreme.
"It was the strategy of the team first to do a quick car and then improve the level of serviceability, instead of starting with a bulldozer and then trying to extract performance."
Changes for this year include way the front suspension picks up on the new monocoque and the mounting of the mandatory illuminated number panels, something which bit Toyota at last year's Bahrain WEC round. And the alternator? "Alternators shouldn't fail," reckons Vasselon.
Andre Lotterer, Benoit Treluyer and Marcel Fassler are seeking a hat-trick © XPB
It is difficult to argue against Audi's combination of Andre Lotterer, Benoit Treluyer and Marcel Fassler, who are bidding for a Le Mans hat-trick this year, adding up to the best prototype line-up in the world right now. And it might be even better than it was over the past couple of years. Fassler has driven fewer stints than his team-mates in the 24 Hours, particularly in 2011, but this season the Swiss driver appears to be on the top of his game.
They have held the upper hand over regular WEC team-mates Allan McNish, Tom Kristensen and Duval so far this year. That is indisputable. But does the trio have a significant advantage over the other two Audi line-ups or those at Toyota? The answer is almost certainly no.
The line-up in the third Audi includes newcomer di Grassi alongside Jarvis and Gene. The Brazilian's pace every time he has climbed aboard an Audi since his prototype debut at Interlagos last year suggests he has the tools to become one of the world's very best sportscar drivers.
The Toyota line-up is made up of a roster of drivers who are either on that list already or, like di Grassi, have the potential to reach it. Alex Wurz, Nicolas Lapierre, Davidson and Sarrazin are in the former group, Kazuki Nakajima and Buemi in the latter.
The events of the Spa WEC round offer some insight into what is going to happen at Le Mans this year, but not conclusively so. The form of the 2013 Toyota in the race suggests that the Japanese manufacturer's pessimism is ill-founded: the car ran ahead of the long-tail Audi until the braking problem intervened in the fourth hour.
The picture is clouded by a first slow stint, caused by tyre-pressure issues, for Gene in the Audi. More time was lost during the first round of pitstops when it swapped to a new set of Michelins, which left it well behind the new Toyota. The two Le Mans cars appeared evenly matched on the stopwatch for the next two hours and there was evidence that the Toyota was lighter on its tyres, though it remains unclear whether this will be relevant through the 24 Hours.
The despondency at Toyota was based more on Audi's qualifying form. The long-tail was 0.7s up on aggregate over the four laps each car must now complete under new WEC rules, and di Grassi's fastest lap during the 25-minutes session was a whopping 1.8s faster than Wurz managed.
The allegation from Toyota is that Audi didn't show its true form in the race, or rather chose not to run at full power.
"We looked better in the race but it was entirely related to the engine settings [of the Audi]," said Vasselon after the event. Asked if that meant he believed that Audi had chosen to run less power for the race, he said: "Exactly; it is a clear conclusion."
Toyota did look the "pushy challenger" at Spa, much more in fact. And that's the role Audi is expecting, and everyone else is hoping it to play at this year's Le Mans 24 Hours.
AUDI VERSUS TOYOTA AT LE MANS
1999 Qualifying Race Audi R8R #7 9th 4th #8 11th 3rd Toyota GT-One #1 1st R #2 2nd R #3 8th 2nd 2012 Audi R18 e-tron quattro #1 1st 1st #2 4th 2nd Toyota TS030 HYBRID #7 5th R #8 3rd R