Renault F1 technical director Bob Bell has said that Fernando Alonso's success in Sunday's Japanese Grand Prix justified the team's decision to continue refining its 2008 car alongside the design and build of next year's challenger.

Locked in a battle with Toyota for fourth place in the constructors' championship, the regie opted to prolong the development of the R28, even though it did not expect to take wins this season. The car, however, has continued to make inroads into the early season advantage enjoyed by its rivals, with Alonso taking back-to-back victories in Singapore and Japan to propel Renault to a comfortable 16-point cushion over its rivals.

"I think the wins in Singapore and Fuji have vindicated the decision to continue the development of the R28 late into the season," Bell claimed, "We could easily have taken the decision to give up on this season and concentrate entirely on next year, but we took a different decision as we felt actions spoke louder than words. While many teams made brave promises about delivering performance next year, we were determined to get results this year.

"You need results to keep up your self-belief and motivation, to keep the support of your partners, and to secure the right drivers. So, from the team's point of view, it was very important to prove to ourselves and everybody around us that we were capable of coming back and being serious contenders.

"It's a feeling of immense pleasure and satisfaction for a job well done, thanks to the efforts of the whole team at the track and in the factories of Enstone and Viry. Everybody has made a direct contribution to these results and it's a fantastic reward for the whole team. I'm elated by it."

While he admits that victory in Singapore owed more than a little to good fortune, as Alonso came from 15th on the grid after problems in qualifying and benefited from an early safety car, Bell insists that last weekend's success in Japan underlined the new-found performance of the R28.

"People would have always looked back at the Singapore result and probably focused on the luck element of it," he admits, "But the result in Fuji has put that to bed and demonstrated that the car clearly has the performance, and the drivers the ability to exploit that performance and bring home race wins. It's a very satisfying result that was achieved on merit, which at this stage of the season is a fantastic performance."

Despite taking 25 points from the two 'flyaway' events, however, Bell is reluctant to believe that the team's aim of being fourth in the constructors' championship has been achieved.

"I never think like that," he stressed, "It's not mission accomplished until the chequered flag falls in Brazil, and we will continue to push and assume that we can still be overhauled. In F1, you should never rest on your laurels and we will keep that in mind when we determine our strategies and approach to the final couple of races.

"We won't approach the [Shanghai] race particularly differently, although I think we now have the self-confidence and belief that we can finish on the podium and challenge for the win. That means that we might take a more aggressive attitude than we might otherwise have done, but we will remain mindful of the need to maintain our points advantage over Toyota."

'Attracting the right drivers' might have been one of the reasons Bell gave for continuing to push for results in 2008, but Renault clearly hopes that Alonso will remain on board in 2008, having been acknowledged as playing a major part in the team's upswing. Various rumours continue to circulate regarding the status of the Spaniard's talks with Honda, but even he admits that back-to-back victories have rekindled his love affair with Enstone.

"I think it was very much a case of Fernando being totally in control of the situation," Bell said, reflecting on the double world champion's win at Fuji, "He had a good car, he was completely dialled into the circuit, and he was able to deliver good consistent lap times to build his lead. He's also a very intelligent driver, certainly one of the most intelligent that I've come across, and he's very good at reading the race and understanding what needs to be done to get an end result. I think his performance in Fuji was a fine example of that.

"Nelson [Piquet Jr] also did a good job all weekend too. He had a little trouble in Q2, with a couple of mistakes, but that was the only time during the weekend that he didn't deliver all that we could expect of him. He was quick from the start, both in the wet and the dry, and drove a strong race to bring the car home in front of the sole Toyota, which is a great achievement."

Key to the team's decision to maintain the development of R28, which began the season a long way off the teams it is now beating, was the team's capability to handle both that programme and still keep on top of the design and build of the R29 which, coupled with the FIA's decision to allow 'engine equalisation' among the F1 teams, could push the regie back among the racewinners from the start of 2009.

"It's important to understand that we haven't lessened our effort on the 2009 project," Bell noted, "Both our facilities in Enstone and Viry are working absolutely 120 per cent on next year's car and we've simply squeezed more out of the system to meet the demands of the season.

"That means people have worked longer hours and put greater effort in to maintain the development of the R28 without compromising next year's car. Once again the people involved have risen to the challenge and allowed us to do this, which is a really strong testament to the whole team."