At the 2023 edition of the 6 Hours of Fuji, car #33, Corvette C8.R operated by Corvette Racing, endured the race on one less stop for fuel than all of its competitors in the LMGTE Am class. It did so while maintaining pace sufficient to grant it the class victory. At the end #33 was classified second, 22.793 seconds behind the winning car #54. This was due to two in-race penalties caused by driver errors, which collectively cost them 1 minute and 15 seconds.

We dive into the data from the last round of the World Endurance Championship (WEC), generously provided by FIA WEC and Al Kamel Systems, to understand just how remarkable this achievement was and how it was accomplished.

Fuel, of course, is not the only reason why teams do pit stops. Changing tyres is another big reason. The optimal strategy necessitates matching the rate at which fuel is consumed with the rate at which the tires lose their grip. In WEC, this also needs to align with the regulations of the sport, which establish the allowed driving time for drivers in different categories.

There is no doubt that the adventurous strategy adopted by Corvette Racing at Fuji was grounded in a solid understanding of their tire wear. The favorable track conditions during the race resulted in relatively mild tire wear. For instance, the Iron Dames team attempted to take advantage of this by double-stinting their tires with their bronze driver, Sarah Bovy. However, this decision turned out to be incorrect, as over that stint, they transitioned from leading car #33 by a margin of 0.7 seconds to trailing them by 8 seconds (this can be observed using the Race Analysis Tool). This is comparable to the approximately 10 seconds it would have taken them to change the tires.

Any race strategy involves a compromise between conserving fuel and tires while sustaining a high average speed. The most common method for saving fuel, without significantly compromising lap times, is by lifting off the throttle earlier before entering the braking zones at the ends of straights.

During the race, car #33 made four fuel stops, with stints of 41, 44, 43, 42, and 40 laps. The middle panel of Figure 1 illustrates car #33's top speed over the course of the race. It's noticeable that during the second, third, and part of the fourth stint, the drivers were lifting off well before the speed trap (located at the end of the main straight), resulting in top speeds as much as 20 km/h lower than the maximum possible. This behavior primarily influenced sector 1 performance, reflected in the bottom panel displaying their sector 1 times, and their lap times shown in the top panel.

It's worth noting that the first two stints were driven by the team's bronze driver, Ben Keating, rightly considered one of the best bronze drivers in WEC. However, there is a substantial disparity in the penalty incurred in terms of sector 1 and lap times when comparing Nicolas Varrone's performance during the third stint, which was only one lap shorter than the second. The last stint, taken on by the team's platinum driver, Nicky Catsburg, did not yield faster lap times than the third and fourth stints, but Catsburg did manage to achieve the highest top speed of 275.5 km/h, which was also the fastest among all LMGTE Am cars during the race. The final stint was 40 laps long, during which #33 was not challenged from anyone behind them but they did close the gap to the car in front.

Figure 2 displays the longest stints completed by all the LMGTE Am cars in all the races of 2023 to date. Stints affected by safety car periods, full course yellow flags, or rain have been filtered out using the algorithm described here. Our focus here is exclusively on the longest stints, as shorter ones are likely constrained by factors other than the allowed amount of fuel. While the majority of racing stints fall in the range of 160 to 190 kilometers, occasional longer stints do occur. However, in 2023 so far, there have been only three stints surpassing 200 kilometers: the second stint of car #33 at Fuji and two stints at Le Mans, both executed by Aston Martin cars, #25 and #98. Thus, stints of this duration are rare but not unprecedented.

Different tracks impose varying demands for fuel. Additionally, the provided data does not specify the reason for a pit stop or the slower segments of the race, which the algorithm used to identify may have missed. Furthermore, the data doesn't include information about the tire compound used, which can significantly impact stint lengths. Adhering to the assumptions outlined earlier, Figure 3 presents all the stints from the 2023 6 Hours of Fuji race in the LMGTE Am class. All of these stints occurred at the same time on the same track. Track conditions experienced relatively minor changes throughout the race, and there were practically no safety car periods.

The left panel illustrates that all five stints completed by car #33 are among the longest during the race. On the right panel, we observe that these stints were also some of the fastest. While the presence of four distinct classes of drivers in the LMGTE Am field contributes to a broad range of lap times, it's evident that all of #33's stints were among the quickest. This suggests that they could have been competing for victory with a five-stop strategy as well.

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