61st Mobil 1 Twelve Hours of Sebring A Quick Look at What It Might Mean With the dust just about settled following the Sebring 12 hours, I have found time for some data analysis. Although the race was the opening round of the 2013 American Le Mans Series, I have to confess that my personal interest was particularly on the performance of the two Audis that ran away from the rest of the field and dominated the race. Just like last year, only different.
I am interested (as I am sure a lot of people are) in what indications it will give us for the 2013 World Endurance Championship, and even more importantly, Le Mans.
First, let's recall some key numbers from Sebring 2012:
62 starters, 325 laps completed. 11 caution periods for 55 laps in total Fastest race lap: Lotterer (Audi R18 TDI)  1m 46.567s
Remember as well that the three Audi R18 TDIs were pretty much 2011 cars: following last year's 12 hour race, they were used for the backtoback comparison tests with the R18 ultra and the R18 etron quattro that Audi would use for the rest of the year and then wheeled away.
Now compare that information with the same from Sebring 2013, when Audi was trying a different strategy, in that the two cars entered this year were both hybrid etron quattros, but one was in '2012spec' and the other in '2013spec'. The most obvious external difference was the rear wing, which on the new car was utilising the 'fullwidth' loophole first exploited by Toyota last year. Sebring 2013: 42 starters, 364 laps completed. 4 caution periods for 20 laps in total Fastest race lap: Kristensen (2013spec Audi R18 etron quattro)  1m 44.870s
At first sight, an improvement of 1.7 seconds.
No analysis from me would be complete though, without mention of average lap times. The most appropriate way to look at it seemed to me to be to look at the average of the best 50 and the best 100 laps from each car. This gives the following:
2012  Audi R18 TDI: #1 Audi average best 50 laps  1m 48.720s #1 Audi average best 100 laps  1m 49.369s
#2 Audi average best 50 laps  1m 48.802s #2 Audi average best 100 laps  1m 49.401s
#3 Audi average best 50 laps  1m 49.203s #3 Audi average best 100 laps  1m 49.822s
2013  Audi R18 etron quattro #1 Audi (2012spec) average best 50 laps  1m 46.489s #1 Audi (2012spec) average best 100 laps  1m 47.048s
#2 Audi (2013spec) average best 50 laps  1m 46.423s #2 Audi (2013spec) average best 100 laps  1m 47.056s
It looks pretty clear that the new etron quattro is better than two seconds per lap quicker than the old R18 TDI. But there doesn't seem any discernable difference between the 2012 and 2013 specification cars, which is surprising.
This is where a look at the sector times is interesting. In the following table, I have taken the fastest 15 times through each sector, and worked out the percentage of the time that the number 1 car (the older spec) was quicker than the number 2 car. So, 100% means that the number 1 car had the quickest 15 times through the sector, 0% means that the number 2 car had the quickest 15 times. If the number 1 car had 10 out of the 15 quickest times, then that would show as 67%.
Sector  From  To  Percentage Advantage to #1 

1  T1  T2  100%  2  T2  T3  27%  3  T3  T4  40%  4  T4  T5  67%  5  T5  T6  47%  6  T6  T7  33%  7  T7  T8  100%  8  T8  T9  53%  9  T9  TA  0%  10  TA  T1  47% 
To make this meaningful, you need to know where each sector is and for this you need the circuit map:
I hope this is clear enough: in effect the old ("lower downforce") car is quicker from the start/finish line to the pit exit and through the speed trap at the end of the Hulman Straight. The new ("high downforce") car demonstrates its advantage out of the final turn onto the start/finish straight. It is interesting that the advantage does not show up through the final turn (turn 17), though, which makes me think that the new car may also have had a different (and more effective) hybrid system. At Le Mans, of course, the cars will run in "low downforce" trim. Indeed, remember that Toyota did not use their revised bodywork until after the 24 hours. So I would expect the folk at Audi to create a 'best of both' solution  certainly for Le Mans, if not for Silverstone and Spa. If they do, will it then be a 'hybridhybrid'?
Paul Truswell
