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"           Since 2009, Formula 1 pitstops have been limited to tire changes. The spectacular sight of a heavy fuel hose being hooked onto a car\u2014with the ever-present threat that something could go wrong\u2014has been consigned to history. Now drivers take to the grid with enough fuel to go the distance.   But anyone who thought that fuel would no longer be a talking point has been proved wrong. And that was never more evident than in Turkey 2009. Well before the end of the race, Red Bull&amp;#039;s Mark Webber was told by his team that he had to start saving fuel, and it was just after he switched to that mode that teammate Sebastian Vettel launched the unsuccessful passing attempt that put both men off the road.   Shortly afterward, radio communications revealed that both McLaren drivers, by now running 1-2, also had to save fuel. Jenson Button&amp;#039;s idea of what that meant was rather different than that of teammate Lewis Hamilton, and the pair had a battle of their own that nearly ended in tears. So why were two of the top teams turning a Grand Prix into an economy run?   The answer is simply that fuel equates to weight, and weight costs lap time. Now, teams cut it as fine as possible, going to the grid with the absolute bare minimum in the tank with which to get to the end of the race. Often they know that a driver will not be able to run flat-out all the way without at some point leaning out the mixture. That can happen in traffic early on, or toward the end, when positions have stabilized.   It comes as no surprise therefore that the teams placed a lot of faith in their fuel suppliers to provide a product that not only optimizes power, but also efficiency. And it&amp;#039;s not just starting weight that was a consideration. For last season, teams had to decide on a maximum size for the fuel tank, based on the calculations of what volume would be required to finish high-consumption races like Valencia and Montreal. The larger the tank, the more compromises there were with the layout of the car and key parameters such as weight distribution.   Scuderia Ferrari has been partnered with Shell since 1996, when the two companies got back together after a break of over two decades. It&amp;#039;s a close relationship\u2014the fuel even has its own part number in Ferrari&amp;#039;s paperwork, while Shell Technology Manager Lisa Lilley even has her own desk when she visits Maranello.            The FIA sets strict limits for the fuel companies in terms of the specification they can use, but within those margins there is still plenty of scope for finding an advantage.   &amp;quot;From our point of view, 2009 was probably the biggest year in terms of fuel formulation in 15 years of F1,&amp;quot; says Dr. Lilley. &amp;quot;There were actually two regulation changes\u2014no refueling and a new fuel spec from the FIA. The new fuel spec was in part to enable us to design more efficient fuels, but in part because the fuel companies had been pushing hard to get a bit more formulation space.   &amp;quot;So it was a huge year for us, and to see it in the public eye was quite exciting because people are now talking about fuel, running out of fuel, saving fuel and that&amp;#039;s good news for Shell. It shows that the fuel can make a difference.&amp;quot;   The rule changes for 2010 provided a challenge, but one that Lilley and her team relished.   &amp;quot;It&amp;#039;s not just about the weight. Obviously the fuel is now sitting in the car the entire time, and it&amp;#039;s going to get hotter. When we had refueling, it was at 10 degrees C below ambient [as allowed by the rules]. So if you did that twice during the race you were actually putting cool fuel into the tank, which had a chilling effect.   &amp;quot;So we had to completely redesign the fuel. We started in the middle of 2009 and now it&amp;#039;s a completely new fuel. There are a number of things it has to do. One, it&amp;#039;s a Shell V-Power fuel, so it has to give good power and performance! Secondly, we suddenly had to be really focused on fuel efficiency, which Ferrari were pushing us for. And thirdly, we had to operate at slightly higher temperatures.&amp;quot;   For Ferrari, choosing an optimum fuel tank size was crucial: &amp;quot;There are a number of tracks where fuel economy would be critical, so we simulated if the fuel looked like this or that, and what size of tank you would need accordingly. There was a lot of iteration going on, but the choice of the tank size was ultimately Ferrari&amp;#039;s. We had to agree on a density of the fuel before they could finalize their tank size. It was a chicken-or-the-egg situation, and that&amp;#039;s why we had to start in the middle of 2009.&amp;quot;   Density is an absolutely key parameter, because the teams are obviously keen to minimize volume and weight. And that inevitably means compromise.   &amp;quot;When you measure fuel consumption, you can do it in terms of volume or in terms of mass. Most of the teams in the paddock would probably go on a volumetric fuel consumption. Mass, or what we call a gravimetric fuel consumption, is something that Ferrari have been interested in the past.   &amp;quot;You have to find the right balance between the weight of the fuel and the volume. Once you&amp;#039;ve set your fuel tank and you know what the maximum volume is, then clearly you want the weight to be as light as possible for that given volume.   &amp;quot;Originally, when we were looking at density, it was about trying to define the volume. That was the winter work, but now we can play with the density to try to lighten the mass. And clearly, we do have a significant fuel-efficiency benefit from 2009, a measurable benefit, via a combination of fuel and hardware, and engine efficiency.&amp;quot;   In 2011 there&amp;#039;s extra incentive to improve economy. Many teams package a KERS (Kinetic Energy Recovery Systems) into the car, and like others, Ferrari has put it below the fuel tank. That means there&amp;#039;s a premium on making the tank as small as possible to help with the packaging constraints.   Shell&amp;#039;s F1 fuel is made at its R&amp;amp;amp;D facility in Chester, England. The spec will change several times a season, and each time it has to be checked and approved by the FIA. At the racetrack, officials take regular samples, which are measured against the &amp;quot;fingerprint&amp;quot; on file. To avoid any problems, Shell constantly checks and rechecks its own fuel over a race weekend.   &amp;quot;The FIA has a lab in the U.K. We send our samples to that lab and it&amp;#039;s preapproved before the race. We expect to have a couple of warnings saying, `You&amp;#039;re on the edge.&amp;#039; If we&amp;#039;re not on the edge, we&amp;#039;re not pushing hard enough! You don&amp;#039;t want to be operating in the center of the formulation space, so we have to wait for the certificate to tell us that the fuel is okay.   &amp;quot;We do it by batch, so if we&amp;#039;ve made a batch to last a few races, we&amp;#039;ll have it approved. Even if the fuel type doesn&amp;#039;t change, the batch might. It will be very, very minor, but we get every batch approved just to be on the safe side. Blending is not an exact art, certainly when you&amp;#039;re blending 20,000\u201330,000 liters of fuel. It&amp;#039;s a bit like making a cake\u2014it can come out a bit different even if you follow the same recipe.   &amp;quot;Once that approval is in place, the FIA can go to the pit garage at any point and the fuel has to be the same as the approved sample. It&amp;#039;s then down to us to do the quality control.&amp;quot;   Two Shell technicians work with Lilley at each Grand Prix. In Europe, they are based in one of the Ferrari trucks, while for fly-away races they have a custom-built freight container that turns into a mobile lab.   &amp;quot;We have gas chromatography analyzers, the same technique that the FIA uses, which is very accurate. We always say if you poured a cup of sugar into Loch Ness you&amp;#039;d detect it using these analyzers.   &amp;quot;We ship about 2000 liters to each race. That includes contingency, because if a drum has been damaged in transit we can&amp;#039;t use it, and literally have to dispose of it, as there&amp;#039;s a risk that the metal has corroded into the fuel. Also if there&amp;#039;s contamination in the car, we have to have enough fuel for flushing. Probably the team will use between 1200 and 1400.&amp;quot;   Shell also provides oils for Ferrari, and development is constant. The mobile lab allows the Shell guys to regularly check samples over a race weekend, potentially detecting engine problems before they even happen.   Unlike in the turbo era, you could put a modern F1 fuel in a production car and drive off down the road (although the reverse does not apply!). It goes without saying that the racing program is the flagship for developments that will trickle down to the general public.   &amp;quot;We never stop our R&amp;amp;amp;D program, trying to improve these fuels, and we&amp;#039;ve been pushing hard. We also started with an advanced bio component, derived from Iogen Ethanol. We are the only team using it\u2014it has much better CO2 emissions. That was something that we decided to put in, not for performance gains, but to show a willingness that we wanted to use the fuel in a way that means something to people who are trying to be more environmentally friendly.   &amp;quot;The rules have changed so that you can use any bio-hydrocarbon, and this is exciting because going forward Shell wants to use F1 for technical innovation, so we need to have the most degree of freedom we can. Shell is investing a lot with technical partners in terms of novel biofuels and we want to use them and test them in F1. We now have the ability to do that, as and when we&amp;#039;re ready to.&amp;quot; "^^<http://www.w3.org/2001/XMLSchema#string>
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