The team that has dominated the Le Mans 24 Hours for more than a decade goes into this year's event not quite sure how the battle with their main rival will pan out.
Audi are the undisputed kings of Le Mans. Eleven times winners since 2000, they have made the race its own and wherever you look around the 8.5-mile circuit, the familiar four rings of the Ingolstadt-based company are visible.
Toyota and Audi running close at the Le Mans test day but how tight will the battle be over 24 hours?
Other manufacturers have come to try and knock Audi off its perch, most notably Peugeot, which generated a passionate rivalry and even claimed victory in 2009, but the German marque saw them off, leaving a gaping hole that was ultimately filled in 2012 by the latest challengers, Toyota.
The Japanese marque put up a strong show last year but in reality everyone was looking at 2013 to see what sort of a fight the manufacturer could take to Audi. However, even after two rounds of the World Endurance Championship, it's not entirely clear where the power really lies.
And that's something that frustrates Audi driver and double Le Mans winner Allan McNish.
"It's quite an odd situation because it's not very often I've gone into the race with so many questions marks over the competition as I've got this year," McNish told The Huffington Post UK.
Allan McNish (R) won the first WEC race of the year - the 6 Hours Of Silverstone - with Tom Kristensen and Loic Duval
With the Le Mans organisers, the ACO, giving some concessions to petrol-based cars, McNish is inclined to believe that the Toyota TS030 Hybrid cars could hold some advantage over Audi's diesel-powered R18 E-Tron Quattros as the extra few litres of petrol the Toyotas can carry may translate to running at least a lap longer on one tank.
"At Spa [6 Hours race in May], Toyota could run for two laps longer than us," McNish said. "We won't know about Le Mans until the race but they should definitely do one lap longer and probably two.
"If that's the case, it means we will have to be a lot faster per lap to equal the disadvantage of having to visit the pits more often."
However, McNish is still not sure how the Toyotas will fare in spite of seeing them in action twice - at Silverstone and Spa - as well as the Le Mans test day at the beginning of June.
"At Spa their Le Mans-spec car was behind ours in qualifying but then it was ahead in the race... so prior to their breaking down that would suggest to me they had good performance out of it but we didn't see it. We didn't see the true picture because they didn't finish the race."
Toyota were unable to take victory away from Audi at Le Mans in 2012
The poor weather on test day also prevented any team really showing its hand but McNish thinks there has been enough indication that their opponents will be very strong, probably in different areas to Audi but definitely competitive.
Looking at his own chances over the 24 Hours, there was no doubting McNish's excitement as he reflected on the progress the team has made over the past year and in particular how the R18 performed in the dry at the test day.
"There's been a lot of development," he said. "Aerodynamically we've made a huge step forward. The car in the Porsche Curves in the three laps I did in the dry on test day was stunning. It absolutely took my breath away how quick it was and how well balanced it was.
"The engine guys have tried to reduce the losses the regulations have imposed and I think they've done a good job there. They've definitely stepped up to the plate."
The former Toyota F1 driver believes that the E-Tron Quattro is now a more complete car and certainly one that is more than capable of victory.
"I think also the difference from last year is that last year was the first year with the E-Tron with all the different new technologies in one car. Last year they probably functioned very well but maybe a bit independently… now it's working better as one homogenous unit.
"We're not at the end of the road, we're still improving but for lap time performance, the efficiency of the car, the fuel economy, the ability to drive it fast then yes, it's right up there, no question about it."
Is it the best Audi he has driven?
"I'll tell you after Le Mans."