Audi's Lotterer, Treluyer and Fassler score the 6 Hours of Silverstone win

Fuel consumption was the theme of the day for the fourth round of the 2012 FIA World Endurance Championship, held at Silverstone in the UK. Audi's double Le Mans-winning trio of Andre Lotterer, Marcel Fassler and Benoit Treluyer took the win after six hours of racing, but it was down to their R18 diesel hybrid's superior economy compared to their petrol hybrid Toyota opposition, rather than outright superior speed. In LM P2, a dominant win for the ADR-Delta team made up for their disappointment at just missing out on victory at Spa, while both GT classes saw more efficient AF Corse Ferrari 458s triumph over the fast but thirsty Aston Martin Vantage V12s.

LM P1

Alex Wurz made a determined start to snatch second place from Kristensen before the field had even made the first corner, but as they shuffled through, Peter Dumbreck spun the JRM HPD, which in turn led to Alex Brundle in the #42 Greaves Motorsport Zytek and Brendan Hartley in the #48 Murphy Prototypes Oreca having to take evasive action. This dropped the two P2 cars and Dumbreck out of the top 20 temporarily, but all were able to keep going without any damage.

At the head of the field, Wurz kept on charging, closing right up on polesitter Andre Lotterer in the #1 Audi within 20 minutes of racing. As both cars attempted to lap the Gulf Racing P2 Lola coupé on the run-up to Maggots corner, Lotterer became boxed in and Wurz saw his opportunity to take the lead. He didn't hold first for long, though, as the #7 Toyota had to make quite an early pit stop, indicating the team was either short-fuelling to run light or struggling with high fuel consumption.

The #1 and #2 Audis made their stops within a lap of each other; with Kristensen in the #2 able to eke out one more lap from his R18 TDI than Lotterer could from the e-tron quattro car. In the LM P1 privateer teams' battle, the #13 Rebellion Lola coupé got ahead of fourth-place qualifiers Strakka Racing by the time the first round of stops had cycled through.

The next time the leaders pitted, there was bad news for Audi in the form of a slight delay changing the #2 car's front left wheel. McNish took over from Kristensen and rejoined, but shortly the Scot was in the pitlane again, suffering a slow puncture on the rear right wheel. A safety car then broke the rhythm of the race temporarily, to let marshals retrieve the stricken LM P2 Lotus Lola-Judd coupé, which had pulled in with terminal engine failure. Kazuki Nakajima, having taken over the Toyota from Wurz, then managed to put McNish a lap down at the restart. Superior fuel economy from the R18 TDI allowed him and Kristensen to win back that lost lap before the end of the race, and they would finish a comfortable third.

Audi's misery continued shortly afterwards, though, as Treluyer in the #1 pushed the #57 Krohn Racing Ferrari into a spin while lapping it. Stewards judged the contact to have been the Frenchman's fault, giving the car a stop-go penalty that saw the gap between his Audi and the second-place Toyota come down to under 40 seconds as the race approached half-distance – with poleman Nicolas Lapierre now behind the wheel of the TS030 hybrid.

Behind the works cars, the #13 Rebellion ran its expected clean and consistent race, but there was trouble for Nicolas Prost in the #12 car, who had a dramatic sideways moment following contact with the #57 Krohn Ferrari, leading to a stop-go penalty that contributed to the car slipping down to sixth place, behind the Strakka Racing HPD. However, it still finished ahead of the JRM HPD, which had a fraught race following Dumbreck's first corner mishap, including starter problems and a trip through the gravel for Karun Chandhok. Later in the race, Andrea Belicchi in the #13 had to deal with a late-race charge from Danny Watts in the Strakka, but the Italian just held on to take another unofficial 'P1 privateer' win for the Anglo-Swiss Rebellion team.

Despite the stop-go penalty for the #1 Audi, as the race entered its closing hours the fuel economy advantage began to show, and the Le Mans-winning crew's lead over their rivals stretched out to around a minute, which is where it would finish. “I wish the battle with Wurz had lasted longer,” said Lotterer afterwards. “But he was faster at that point of the race so he would have got past eventually. We were struggling a bit on worn tyres in traffic but otherwise things worked out fairly well.” His team-mate Treluyer added: “Our strategy was simply to go as fast as possible all the time. The penalty changed that a little bit, but we were still able to do it.” The result means Lotterer, Treluyer and their Swiss co-driver Fassler now lead the WEC drivers' championship with four rounds to go.

With this being only the team's second WEC race; the Toyota trio were understandably not too disappointed to finish second, especially as they had outpaced the Audi at times during the race. “We're fighting a decade of domination by these guys,” Wurz declared afterwards. “They have the experience, but we've shown we have fighting spirit.” Wurz's fellow former Williams F1 driver Kazuki Nakajima echoed these comments, saying: “I knew we had to make one more stop than the Audis, but at least we showed good speed and I enjoyed my battle with Treluyer in the middle of the race.” Qualifying driver Lapierre was optimistic for the rest of the season. “We lost about six seconds to the Audi at each stop due to how long it takes us to refuel,” he explained. “So if we can sort out that fuelling problem, we'll definitely have a chance to win before the end of this year.”

Although several problems dogged Kristensen and McNish's car throughout this race, they were not far off challenging the Toyota for second towards the end. “I think I was a little too hard on the tyres and I began suffering oversteer in the faster corners,” said Kristensen.

LM P2

The ADR-Delta team looked racy from the word go in the smaller prototype class, as John Martin took the team's Oreca-Nissan past Nicolas Minassian's JOTA Zytek for second in class. The French ex-Peugeot driver, making his debut for the British privateer team, didn't leave things that way for long, though, and was soon back into second as the pair fought hard behind the class leader and second-place qualifier Stephane Sarrazin in the Starworks HPD. As mentioned above, pole position qualifier Alex Brundle in the #42 Greaves Motorsport Zytek suffered a nightmare start to the race when he had to leave the track to avoid a spinning LM P1 car. A stop-go penalty for passing under the safety car later in the race then put paid to any chance of a recovery drive for this crew.

Fifth-place qualifier Brendon Hartley in the #48 Murphy Prototypes car was also disadvantaged by Dumbreck's spin, but was putting in an impressive recovery drive until a wheel coming lose on the start-finish straight spoiled the race for the young New Zealander. OAK Racing suffered contrasting fortunes for its two Nissan-engine cars: the #35 lost huge amounts of time early in the race with a faulty starter motor, yet the #24 with team boss Jacques Nicolet aboard was challenging for the lead by the half-way point of the race.

But ADR and Starworks were still in the mix as the race entered its closing stages, the former leading the latter by over a minute thanks to the effects of two safety-car periods and a solid middle stint from ADR driver Tor Graves. Following retirement for the #23 Signatech car of Jordan Tresson, the French team's less-fancied second car crewed by Roman Rusinov, Nelson Panciatici and Pierre Ragues found themselves in contention for a class podium. They couldn't live with the pace of Sarrazin in the Starworks car, who disappeared into the distance in an attempt to chase down the ADR for the win, but they did bring it home in third overall – by far their best result so far this season. Sarrazin put in a typically fighting drive in his final stint to come home 5.6 seconds behind the winning ADR Delta car. “It was great to win this one, as I live just across the road,” said its British-based Australian driver Martin afterwards. “It was a good fight with the Starworks car early on, and we had a good strategy that we stuck to all race,” he continued. His Thai co-driver Tor Graves had been struggling for confidence in Friday's and Saturday's sessions, but it all came together for him in the race. “I took it easy at first, the car felt good, so then I started pushing and the lap times came,” he recalled. A disciplined final stint from Jan Charouz was enough to resist the Starworks challenge and take ADR-Delta's first win of the season.

GTE Pro

An action-packed early part of the race saw Darren Turner in the #97 works Aston Martin catch and pass first James Walker in the JMW Racing Ferrari, then Gianmaria Bruni in the #51 AF Corse Ferrari. Now running second behind polesitter Richard Lietz in the #77 Felbermayr Porsche, Turner was the first of the leading group of GT cars to pit – showing the V12 Aston couldn't match the V8 Ferrari's fuel consumption. It looked like the Ferrari/Aston battle would be for second place behind Lietz and his co-drover Marc Lieb, but shortly after the second round of stops, the #77 Porsche's right-rear suspension collapsed as it drove through Abbey corner, forcing Lietz to complete almost a full lap with a badly compromised car and putting them down to the bottom of the GT pack.

This left the Fisichella/Bruni and Turner/Mucke duos swapping the lead through the pitstop cycles, but the superior fuel consumption of the Ferraris soon saw the Aston overhauled by both James Walker/Johnny Cocker in the #66 JMW Racing 458 and Olivier Beretta/Andrea Bertolini in the #71 AF Corse 458. Fisichella and Bruni had a comfortable two-lap lead by the time the chequered flag fell. “We tried to follow Lietz as close as possible at the start, but the Aston came up fast behind us,” said Bruni, “so we had to try and match its speed while still using less fuel and we achieved that 100 percent. The safety cars weren't a concern – they would have had to be out much longer before the Astons could have saved a pit stop.”

Behind them, the JMW Ferrari duo had a 40-second cushion over a furious battle for third between Bertolini and a chasing Mucke in the #97 Aston. Things came to a head on the last lap, when the two cars came together in an incident reminiscent of the closing laps of Sebring this year, which left Bertolini's car scrabbling in the gravel and Mucke's crossing the line badly damaged in third place.

GTE Am

Ferrari fuel mileage proved decisive in the second-tier GT class battle, too. Stuart Hall led the Aston Martin challenge from class pole, but he was quickly overpowered by Marco Cioci in the fast #61 AF Corse-Waltrip 458. But Felbermayr Porsche's Paulo Ruberti, who had narrowly missed out on class pole in Saturday's qualifying session, was showing similar pace to his pro-class team-mates and had soon moved up to first in class. The #61 Ferrari trio bided their time, however, knowing they could run the race with one less pit stop than the Felbermayr car.

“Our strategy was the same as the #51 Pro car,” said Cioci afterwards, “so we had to run hard at the start to match the Aston and Porsche.” Irishman Matt Griffin's strong double stint was key to the win, and he said the result was in sight from around the four-hour mark. “We had to push, even though we were running a lean map,” he said. “We had a slight issue with the air jacks at the last stop, but it was under control. WEC races are hard and there are a lot of good drivers to beat, so everything has to fall into place. We're chuffed to win here.” Cioci and Griffin's co-driver Piergiuseppe Perazzini, involved in the massive Toyota crash at Le Mans, said the victory was particularly satisfying after a self-confessed difficult several weeks in the aftermath of Le Mans.

Second and third in the amateur GT class went to the #50 Larbre Competition Chevrolet Corvette of Julien Canal, Patrick Bornhauser and Fernando Rees, following a quiet run that saw them keep out of trouble – a signature Larbre performance. Despite showing good pace early on, the #88 Felbermayr Porsche crew of Ruberti, Christian Reid and Gianluca Roda had to settle for third.