Tuesday, 22 April 2014

Five and a bit hours of Silverstone

I’m not sure that the opening round of the 2014 World Endurance Championship at Silverstone will go down in history as a classic race; but nevertheless it was a fascinating encounter and one which provides plenty of food for thought ahead of the next round at Spa, and more importantly the 24 hours of Le Mans in June.

With a little over a week before the teams assemble at Spa-Francorchamps, there is much to do at Ingolstadt, Cologne and Stuttgart, and also of course at the various suppliers that support Audi, Toyota and Porsche.

Obviously, Toyota had a perfect result at Silverstone, bringing home its TS040 Hybrids a lap apart and a lap ahead of the competition, but is that a realistic reflection of the pecking order?

The only period of the race for which a comparison can be made for all 6 LMP1-H cars is the first 20 laps - before the first rain shower sent everyone scurrying for the pits (or in Audi’s case, the gravel).

No. Car Driver Best Average
1 Audi R18 e-tron quattro Di Grassi 1m 44.656s 1m 46.104s
2 Audi R18 e-tron quattro Lotterer 1m 44.217s 1m 45.903s
7 Toyota TS040 Hybrid Wurz 1m 44.326s 1m 45.933s
8 Toyota TS040 Hybrid Buemi1m 44.708s 1m 46.304s
14 Porsche 919 Hybrid Jani 1m 45.452s 1m 47.223s
20 Porsche 919 Hybrid Bernhard 1m 45.245s 1m 46.733s

Before reading too much into this, though, remember that the two Porsches were in Le Mans ‘low-downforce’ trim, whereas both Audi and Toyota had aerodynamic set-ups more suitable for the demands of the Silverstone Grand Prix circuit. If I were in the Fritz Enzinger’s shoes at Porsche, I think I would have wanted to be a little closer on lap times, but even so, the times shown above are encouraging for all concerned.

It’s worth pointing out as well that not only was the ‘average’ Audi ahead of the ‘average’ Toyota in lap times, but also in consistency: the Audi lap times are slightly less spread than those of the Toyotas.

Just before the race, of course, there was a small tweak to the regulations, aimed at balancing the petrol-diesel equivalence, reducing the amount of fuel that Audi could carry and increasing the amount available to the petrol-fuelled manufacturers. This tweak also reduced the rate at which Audi could pour the fuel into its (smaller) tank, so it really was a ‘triple-whammy’. It won’t matter, of course, at Le Mans, unless that half-litre reduction makes the difference between 13.1 and 12.9 laps on a tankful. But my calculations before the Silverstone race suggested that Audi would be comfortably in the 13-lap range on a tank: I don’t think they would have been considering 14 lap stints anyway.

Again, though, the data from Silverstone is interesting, if minimal. Audi only completed one full stint that wasn’t affected by changing weather conditions, when Benoît Tréluyer drove the no. 2 car from 13:51 to 14:41, completing 27 laps, with an average lap time of 1m 47.826s.

There was more data to go on from Toyota and Porsche. Both Toyotas managed 28 laps on a tank of petrol, without assistance from the Safety Car, in the hands of Nakajima and Lapierre. Nakajima was the quicker of the two, averaging 1m 46.978s for his stint - a pace that surely must be a concern for Audi.

Brendan Hartley completed the longest stint for Porsche (unassisted by the Safety Car), completing 29 laps from 13:39 to 14:33. The average lap time for the stint was only 1m 49.171s though, which perhaps goes some way to explaining its economy.

But again, before reading too much into this, remember that even two laps of Silverstone is less than a lap at Le Mans, so fuel economy may not be the deciding factor this year. Time spent in the pits could be though: time spent sitting stationary in the pit lane while fuel is going in or the tyres are changed can take a lot of effort to get back on the track.

The table below shows the fastest fuel only (full stint) and driver / tyre change stop for each of the LMP1-H teams. As always, this is the time spent in the pit-lane, rather than just the time spent at rest.

Car Fuel only Full service
Audi R18 e-tron quattro 1m 01.222s 1m 21.794s
Toyota TS040 Hybrid 1m 03.574s 1m 24.139s
Porsche 919 Hybrid 1m 10.196s 1m 28.186s

No real surprises here, I suppose, other than the size of the differences. Certainly, there seems no need for Audi to complain about the rule change; and for Porsche, there seems to be some room for improvement still.

Prospects for Spa? For sure, we can expect a good race. I admit that the limited analysis I have presented here does not make it clear whether we can expect Toyota or Audi to have the upper hand in the Ardennes. There will likely be a third car from Audi (in Le Mans trim, perhaps?). It may well come down to the abilities of the individual drivers to get the best from their steeds. Although changeable weather conditions can throw up unexpected results, a dry, uninterrupted race will make it easier to predict what might happen at Le Mans. On the other hand, Le Mans is seldom predictable and always thrilling.

Finally, hats off to all concerned that the opening round was free of controversy. Long may it remain so!


  1. Great read pail.thanks

  2. Paul, I was watching on the start/finish straight at the start and I noticed while the 7 was ahead, the Audis caught up and eventually passed and made a gap, but the 7 started to catch back up when the rain started (before pitting). I wouldn't expect that if Audi had high downforce. Do you think Audi's setup/temperature window might be smaller?

  3. Hi Paul,

    I have always found the diesel vs petrol balance very interesting. I fall into the camp that thinks last year petrol have had the upper hand simply due to the extra range and Audi won races by having the better overall package of car+team.

    Watching the race from trackside Sunday showed the strengths and weaknesses of each marque. The Audi was far better under breaking and quicker round the corners. Come a straight the Toyota just pulled away.

    So a novice, like myself would surely conclude that, as last year, Toyota have the power advantage and Audi possibly the better overall package.

    This will make for some exciting racing I am sure. My fear is that the current fuel balance has gone too far in the favor of petrol. Before the race I did some sums and concluded that for a dry race Audi would have to stop once more than Toyota or Porsche at Silverstone.

    You mention above that Audi managed 27 laps and Toyota and Porsche managed 28 so I pleased I was on the right track.

    I had the privilege of a quick chat with Andre Lotterer who confirmed that Toyota would be able to do 1 more lap than Audi on a tank of fuel. And that was why they tried to get clever with tyre strategy and stay on slicks for what they thought would be 20 minutes when it started raining.

    On the day the Audi was the faster car - but not nearly fast enough to make up for an additional pit stop. I did the sums and even in the rain shortened and slower race this weekend Audi would still have needed to pit once more.

    I think it will be a great shame if the regulations have had the opposite effect than intended and just handed the crown to petrol. The whole point of these new regulations was to equalize the technology - not the package. Surely it can't be that difficult to get the balance near enough that all teams can stop on the same lap?

  4. Hi Paul, an interesting analysis, as always. Looking forward to Spa and obviously even more so to the annual trip to Le Mans. :)