Bob, was the R25 a successful car?
Bob Bell, Chassis Technical Director: Looking at the results, yes! In engineering terms, for a car to be considered successful, you cannot afford to have any weaknesses in the technical package. The same thing is true on a human level with the team. If you have a problem in one area, it can have a serious effect on overall performance. And our car didn’t have any obvious weaknesses, neither with the engine nor the chassis.

When you are in the design phase, have can you be sure you haven’t taken too many – or too few – risks?
BB: You can never be completely sure of anything. There are still lots of unknown factors when it comes to getting the best out of a Formula 1 car. Our job is to manage the risks. If you don’t take any, then you go backwards. If you take too many, then you can have serious reliability problems. The 2005 season showed we had found a good compromise with the R25. We innovated in some areas, but we did it in a controlled way.

Was that one of the car’s secrets?
BB: Perhaps. We always tried to consider reliability as our priority, and to improve performance without endangering our ability to finish races. That strategy paid off: the R25 may not have been the quickest car at every race weekend, but it was the most competitive over the whole season.

Is the search for reliability a constant preoccupation at Renault?
BB: You can never take reliability for granted. A part may have performed perfectly during 7 races, but you always need to ask whether it will last for race number 8. Performance is constantly increasing, and that means the safety margin on each part must be sufficient – but small. It is easy to go over the limit. For example, if you make the car easier to drive, that allows the driver to attack more, to use the kerbs: when that happens, something might break without warning. In our minds, it is not a question solving problems so much as anticipating them by trying to imagine every scenario. It is a continuous challenge.

For 2006, Renault will not run its V8 engine until the new car is ready. Is that a worry in terms of reliability?
BB: I don’t think so. We are not at all complacent about the work involved in making the new package reliable for the opening races, but we have adjusted our project timing to take account of this. Our new car will run early in 2006, and we will get two chassis running as quickly as possible to maximise our track testing time. We believe this is the most effective and balanced use of our resources, taking into account the fact we had to develop the R25 until the end of 2005 in order to secure the championships and that our engine architecture will change for 2006. Our priority is to produce a competitive package with which to defend our titles next year.