Friday, 5 July 2013

Le Mans 2013

I have been somewhat slow in posting anything about Le Mans 2013 on this blog. There are a number of reasons for this; among them: firstly, that I was busy in the immediate aftermath of the race writing up a long analysis for Racecar Engineering, which should appear in the next issue of that magazine. Secondly, I have been busy at the routine tasks of my day job. Thirdly, that I seem to have had lots of jobs to do at home that needed my attention. But fourthly, and perhaps most relevantly, I’ve spent a good deal of time mulling over the death of Allan Simonsen.

I’ve commented on death in motorsport before in these pages, (here, if you missed it) and it is not my intention to repeat my thoughts on the matter. However, when one considers the scale of some of the accidents that have occurred at Le Mans in the past twenty years or so, I was somewhat taken aback that the accident that looked relatively innocuous at first viewing could have such terrible consequences.

Emotions run fairly high as a matter of course in the Radio Le Mans commentary box, particularly at Le Mans, and I found myself on more than one occasion having to re-focus attention on the on-going race, rather than dwelling on sentimentalities. It was the first time that I had been hooked into the team Skype channel, which enables John, Eve, our London studio and some others, to have off-air ‘conversations’ during the broadcast, and thus it was that I learned the news before the official press releases were issued. And due to the nature of the news and how it broke, we at Radio Le Mans had to confront it, head-on and for real.

Although I wouldn’t count Simonsen as a friend (I have few enough of those), I had met him on a number of occasions. I was impressed watching him at first hand in British GT races, and had interviewed him for circuit PA in the pit lane. There was also the inaugural Dailysportscar Cricket Match in 2008, which Allan attended,  and which provided a memorable opportunity to chat on a range of subjects, including the pronunciation of his surname, about which he was relaxed.

But I think it was the very fact that we have dodged the bullet so often at Le Mans that was the reason this year, that its impact, when it hit home, was so shocking. It was a hard race, in every way.

But, to use a well-worn phrase, back to the race. What a well-deserved, well-executed and thorough victory it was for Tom Kristensen, Allan McNish and Loïc Duval! A slow puncture aside, it was a fault-free run, as it had to be, given that there was always at least one Toyota close behind.

After the race, though, there was a press release from Audi that got me thinking. “Audi most efficient in the field”, it read, and there’s nothing quite like an extravagant claim to get me rushing for calculator and spreadsheet. The Michelin Green X Challenge is something of a dark niche, but having failed to get to the bottom of the calculation used, (despite email requests to Michelin, answers have not been forthcoming) I have developed my own “Index of Efficiency” for the 21st century.

Just as in the 1950’s and 1960’s my “Index” is based on the simple ratio of average speed divided by fuel consumption. The average speed is the speed of the car when it is on the track, so it is a matter of subtracting the time spent in the pits from the aggregate time of the car for the race, and dividing by the number of kilometres completed. It being France, fuel consumption is calculated in litres per 100kms.

However, since diesel has a higher calorific value than petrol, (measured in megajoules per litre), I apply a factor of 13% to the diesel-powered cars to come up with the following:

Average Speed (km/h)
Fuel Consumption (l/100km)
Index of Efficiency
Audi e-tron quattro
Audi e-tron quattro
Audi e-tron quattro
Toyota TS030 Hybrid
Toyota TS030 Hybrid

No argument, then, that Audi had the most efficient car at Le Mans. But more interesting, perhaps, is a comparison with last year’s race, in which Audi achieved an Index of Efficiency with the winning car of Lotter, Tréluyer and Fässler, of 5.870, compared to Toyota’s 5.017, which admittedly only completed around seven hours of the race. Audi's second-placed R18 e-tron quattro, in the hands of Kristensen, McNish and Capello, achieved an even more impressive 6.127.

In case it is not already clear, the way this calculation works, a higher Index of Efficiency means a more efficient car. So although Toyota would appear to be much the same as last year, it seems that this year’s Audi is up to 10% less efficient than last year’s car.

The Michelin Green X Challenge works the other way round - i.e. a lower index indicates more efficiency. But the same pattern is evident in that calculation too: last year Audi won with an Index of 5.26, this year it was 6.10, an even more significant change.

Unfortunately, in order to qualify for the Michelin Challenge, you need to finish the race, so figures for Toyota are not available for 2012; however, it is possible to make a comparison between Audi and Rebellion. Last year, Rebellion’s most efficient Michelin Green X Index was 83% of the best Audi, this year it was 91%; further evidence that Audi sacrificed efficiency for speed this year.

Now normally, I do not spend a lot of time fretting about the Michelin Green X Challenge, or on matters of fuel efficiency – after all, racing is more about speed than efficiency. But in 2014, the regulations are going down the route of allocating fuel based on the efficiency of the engine, and so understanding the nature of these calculations is going to be critical.

At the beginning of this year’s WEC season, Ralf Jüttner admitted that the reduced size of the engine air restrictor had forced Audi to take the less efficient route in order to stave off the challenge from Toyota. In defining fuel allocations for 2014, the FIA / ACO will be looking at the evidence from 2013, and could well find themselves in the role of kingmaker.

For sure, there will be plenty of to-ing and fro-ing before regulations are issued, and even after they're published, don’t be surprised to see some adjustments as we go through the early season races of next year as well.

Of over-riding importance, though, is that measures taken in response to Simonsen’s accident are well-considered and well-judged. It is essential that lessons are learnt, but the response must be appropriate. The FIA and ACO have a lot of difficult decisions ahead. I do not envy them the task.

Postscript: Following further analysis, I also picked up on Audi's assertion that the winning car completed the race using 16 sets of tyres. This means that each set lasted, on average, 21.75 laps. Last year's winning car though, completed 378 laps on just 13 sets, an average of 29 laps per stint. I leave it to the reader to decide whether 2012 or 2013 was the more 'efficient' victory!


  1. The tragic events at the start of the race this year left a cloud over a fascinating race. I have to say how well the RLM team handled unfolding events. For my group of friends, we all felt a measure of guilt at enjoying a race for which a terrible price was paid, on the other hand, it's a reminder that this sport is dangerous and that racing drivers knowlingly take risks in a sport that they love for fans like me who love their sport. My thoughts are very much with his friends and family.
    The efficiency challenge at the front of the grid was very interesting as was the fact that, regardless of speed differences, how close Toyota really were to a win. For Audi to 'lose' some efficiency over last year must mean that they are not as efficient at converting diesel into kinetic energy this year. This cannot simply be because they have wound up the boost pressure as I belive that this is regulated anyway. Unlikely to be due to more internal friction so it would be interesting to know exactly what they have done to generate more power with a fixed boost pressure and inlet restrictor.
    What's even more astonishing his that Porsche can build a new car, turn up and win out of the box. As fans, we don't get access to live speed trap or sector time information and I would be keen to learn how and where the porsches were making the time. Equally, where and how were both the Corvettes and the Vipers losing time? My guess would be through the Porsche curves (and that is a guess) where car development will gain more time (hard to find a lot more power, more likely to gain aero advantage, again, just my guess).
    Paul, thanks for both your commentary during the race and continuing with this blog despite such a hectic life away from the keyboard!

  2. I listened to RLM trackside the moment JH read the statements out from the ACO and AMR relating to Allan's death - and it PT that continued the commentary after what seemed an eternity -I was rather dazed by the shock- and it was clear that he was shocked too - be carried on PT did nevertheless - it was a very very touching moment