Sunday’s Turkish Grand Prix was a fairly normal race by 2010 standards until the controversial collision between the two Red Bull team mates.
But that collision happened because of some big decisions on fuel saving tactics, which are becoming clearly a critical part of the story behind the races. And in the case of the Red Bull collision it lead us to reach a fascinating conclusion.
And what has been exposed by this incident is how teams are managing the fuel use during the races, how little margin everybody is running and how close they all are to running out of fuel at the end of the race.
The collision was only possible because Vettel had a sufficient speed advantage on lap 40 to attempt the pass. Now the team has said that this was due to him having saved fuel early in the race, whereas Webber was in fuel saving mode. So let’s look at what the teams are doing and drill down into this Vettel fuel saving explanation.
The first point to make is that the conditions in Istanbul contributed significantly to the cars using more fuel than predicted in the race. After very hot conditions in practice, the temperature dropped and the track became more grippy. So the race was faster. For every half a second per lap you are faster, you will use 1% more fuel over the course of the race, which adds up to around 1.5 kilos. So you can see how tight the calculations are.
What is interesting is that engineers tell me that the difference in fuel consumption between the Mercedes, Ferrari and Renault engines isn’t particularly significant, based on calculations of how the car performs in the race relative to its performance on low fuel in qualifying.
For Vettel to have saved a kilo of fuel by lap 40 is quite significant and it indicates that he was planning a late attack on Webber, at a time when he knew that the Australian was in fuel saving mode.
Now at Istanbul the weight of the fuel for each lap is worth 8/100ths of a second of extra lap time, just under a tenth. So one kilo of fuel, which is what Vettel is supposed to have saved, would give him a speed disadvantage of 5/100ths of a second over Webber in pure fuel weight. Then you have to factor in the fuel saving mode that Webber was on compared to Vettel at the time.
The teams have an “ideal mix” for the first part of the race to the pit stops. You use that do do your fastest time to the first stop because you want to spread out the field and get clear of the cars behind you. Of course you have to trade that off against looking after the tyres, but that is the general rule all teams adopt.
After the pit stop your track position is more or less set and so then you go into fuel saving mode and you can go leaner and leaner on the fuel mix as you head towards the chequered flag and your track position looks more and more fixed. This way you have the smallest power loss early in the race, where you want it. The teams have a piece of software which helps them with this process, but you can see that the driver has a lot of management to do.
If you go onto a setting with a 3% saving, you will be around 1/10th of a second slower. If you go more into more extreme fuel saving mode – to say 6% – the lost time is greater pro rata because it affects the revs you can run and so you are 3/10ths slower.
Let’s assume that this was the difference between the two Red Bull cars in lap 40, does it fully account for the speed differential between Vettel’s car and Webber’s on the back straight? In both the first two sectors of lap 40, Vettel’s straight line speed was 7km/h faster than Webber’s, but he was only a tenth up on Webber on lap 40 after two sectors, having been two tenths faster on lap 38. The pair set more or less identical times on lap 39, when Webber asked the team to slow Vettel down. Webber’s pace and ability to respond would indicate that he wasn’t suffering from rear tyre wear as has been suggested.
It looks to me like Vettel planned the move all along, having lost out in qualifying due to a mechanical failure on his car, he had a strategy which would give him a golden lap, when Webber would be saving fuel, in which to attack him. And if this is the case then one assumes it must have been sanctioned by the team. Perhaps they felt they owed it to him after letting him down again with the car in qualifying.
It brings into question the whole issue of transparency between team mates. In a tight championship fight, such as this, should the driver who qualified less well be given a chance to get back in front or should this be a team game where the team walks away with maximum points, regardless of who wins?
This incident has blown open the whole issue of fuel strategy and it will be fascinating to see what tactics drivers choose to employ from now on, especially in a battle between team mates.