During 2012, Toyota with a 73 L petrol tank was always beaten by Audi with a 58 L gas oil tank on range [table 1]. At Le Mans, the TS030 completed only 11 laps maximum per stint in green flag conditions versus 12 laps for Audi. The diesel engine prototype even completed 16 laps during a stint, but a part of this stint was done during safety car. So Toyota was completing a distance 8.3 % smaller than Audi at Le Mans 2012.
It was not the worst circuit for Toyota. On all other circuits but Bahrain, Toyota completed per stint a distance more than 10 % smaller than Audi. The worst circuit was Silverstone, with 13.8 % less. An average gives 161,6 km maximum per stint (35.9 L/100 km) for Audi, versus 145.0 km (50.4 L/100 km) for Toyota last year.
Of course, these consumptions numbers are unofficial and calculated considering the fuel tank is full when leaving the pits and empty when the stint ends, so they are an upper limit.
In 2013, the situation is really different, the two manufacturers having chosen different direction to improve. At Silverstone and Spa, Toyota completed more laps than Audi per stint, doing one more at Silverstone and two more at Spa. Audi’s consumption was hugely increased at Silverstone from 34.0 to 39.4 L/100 km (+16%) and at Spa from 34.5 to 41.4 L/100 km (+20 % !), in favour of more performance. Toyota did not race at Spa last year and at Silverstone the Japanese car’s consumption was reduced from 49.6 to 47.4 L/100 km (-4.4 %).
Regarding the distance, the R18s were able to cover 147.3 km maximum at Silverstone, 23.5 km less than last year. Then at Spa they were only able to cover 140.1 km (less than the distance covered in UK minus one full lap of the Belgian track), 20.8 km less than in 2012. So the maximum distance the Audis have been able to cover per stint this year compared to last year has been reduced by 13.8 % at Silverstone and 12.4 % at Spa.
Audi was able to cover 163.55 km at Le Mans in 12 laps last year. If we reduce the distance as for Silverstone, we have now only 141.1 km as the maximum distance the R18s will be able to cover this year. If we reduce as for Spa, we have now only 143.3 km. Ten laps in la Sarthe means 136.3 km and 11 laps means 149.9 km. So Audi should only be able to do 10 laps stints at best this year in the 24 hours outside of safety car periods. And the german manufacturer did just that at the test day. As shown in the table 2, the Audi #3 did two 10-lap stints during the morning, then again two during the afternoon. The Audi #1 did also two 10-lap stints during the afternoon.
For Toyota, only Silverstone can be used to compare the distances : 147.3 km in 2012 and 153.2 km in 2013, so the maximum distance was increased by 4.0 %. If we add this to the maximum distance covered at Le Mans last year, 149.9 km (11 laps), we have now 155.9 km, not enough for a 12th lap (163.55 km). But since Spa, the fuel tank capacity of the TS030 has been increased from 73 to 76 L. The 3 liters added are 4.1 % of the initial tank capacity. With this bonus, the 155.9 km become 162.14 km and just 0.41 km missing to complete a 12th lap… Can this small distance be gained by reducing the performance a little bit ? All these calculations are done considering an empty fuel tank when arriving in the pits. Of course, there’s still some fuel in the tank not used. For 0.41 km more, with a consumption of around 47 L/100 km, less than 0.2 L would be needed… Is the safety margin big enough for Toyota to complete this 12th lap ? A big part of Toyota’s chances this year are in this 12th lap…
Is Toyota hiding its game ? As shown in table 2, the TS030s did only one 9-lap stint last Sunday, during the afternoon, and three 8-lap stints. In this area, Toyota’s work was more like the work done by the Audi #2, that also did shorter stints than the #1 & the #3. Race stints for sure were not done by Toyota during the test day, as they did 11-lap stints last year…
Pascal Vasselon told at the test day that they need to analyze the gain, as 3 liters is less than a half lap. He was not sure to be able to do one lap more thanks to them and that they won’t put them in the car if it’s unuseful, as 3 kg means 0″1 / lap, so 1″2 / stint (so you’ll do 12 laps ?) and around 30 to 35″ over 24 hours.
PS: Regarding the impact of adding 3 liters to the Toyota’s fuel tank capacity, it is interesting to considering that the two R18 ultras entered at Le Mans last year did 12-lap stints, as the e-tron quattros. So yes, 3 liters are not enough to do one lap more of La Sarthe circuit alone, but if you add the fuel consumption improvement from 2012 to 2013…
David Legangneux