Le Mans Test Day Reflections: Part One, LMP1

In a word, inconclusive. That was my response when I was asked, at the end of the Le Mans Test Day, what I thought it all meant. With mixed weather conditions and three red flags, we were not really allowed to see the true potential of many, if any at all, of the leading contenders.

The final list of times shows the leading Toyota five seconds slower than the leading Audi, but this is not at all indicative of the real performance difference between the two manufacturers.

Certainly, the Audis were on top for most of both of the four hour sessions, but neither they nor Toyota was able to work through the entirety of their designated programme of work for the day. And that fact alone is likely to affect Toyota more than Audi.

The longest stint by an LMP1 car was done by an Audi. Two of the Audis achieved ten laps on more than one occasion both before and after the lunch break. However, the fuel consumption data that I have seen is compelling – Audi will only be able to manage 11 laps on a tank of fuel if the average lap time for the stint is 3m 30s. Toyota’s target must be better than this – even last year’s car was able to achieve an average of 3m 29.8s for 11 laps, without the benefit of the extra three litres of fuel that the ACO has announced. The extra fuel allowance for Toyota will almost certainly mean that 12 laps will be achievable this year.

The big question for Toyota is how quickly they’ll be able to lap. At Spa-Francorchamps, there was not much to choose between the new Toyota and the long-tail Audi, in terms of the lap times. The analysis that I did following the race showed that the long-tail Audi was two-tenths quicker than the new Toyota in the first part of the race. Around Le Mans, that will translate to maybe half-a-second over a lap.

If that is the margin at the 24 hours in less than two weeks, and if the weather stays dry and we don’t get any safety cars, then 400 laps will be possible – another new distance record. But who will win?

The table below shows the scenarios, assuming that Audi is quicker, but has higher fuel consumption. For the moment, I am assuming that the tyre strategies are the same – i.e. both Toyota and Audi run the same number of stints on a single set of tyres.

[sws_divider_small_padding]If, however, Audi can run for longer on a set of tyres than Toyota, then 25s or more can be saved on the pit stops where no tyre change is necessary. This changes the situation:

[sws_divider_small_padding]Note that, for those who are checking my arithmetic, I am also assuming that each Audi pit stop will be one second quicker than Toyota – due simply to the additional refuelling time for the petrol teams.

We should not ignore the privateers, especially as it seems possible that the Rebellion Lolas will be able to achieve 13 laps on a tank of fuel. Unfortunately, such has been the development at Audi and Toyota, I think the Lolas will be more than three seconds per lap off the pace. However, that does mean that, according to my calculations, we could have a Lola leading (for a lap) as the Hybrids make their first pit stops. And if any of the works cars has to make an unscheduled stop of more than 15 minutes, then that will be enough to allow a privateer car into the top five.

Paul Truswell