The 2010 season has just passed its halfway point. What would be the half-term report for Renault's F1 engines?
Rob White, Engine Technical Director: We are not fully satisfied, but we are still very proud of what we have achieved. Renault powered cars have taken ten pole positions in 11 races; set six fastest laps; and scored 12 podium finishes, including five race wins. What's more, in Monaco, we scored our first one-two-three finish since 1997. It is rewarding for all the team at Viry who work constantly behind the scenes to achieve both performance and reliability.

Our commitment to total equality in engine supply is reinforced by these great results. Of course, we enjoy a close relationship with Enstone for historical reasons, but we provide exactly the same engine specification and level of support to both our teams: Renault F1 Team and Red Bull Racing.

There has been speculation that the Renault engine suffers from a power deficit relative to its rivals. What is your view on the matter?
RW: I believe the maximum power of the Renault engine within the useful RPM range is not as good as the best of its competitors. Analysis of observed car performance supports this conclusion but it is impossible to accurately quantify differences in engine power except by comparison of power measured on the dynamometer.

The reasons for this deficit are historical, resulting from engine developments undertaken during successive cycles of engine homologation. Changes to the engine have been restricted by the Sporting Regulations since the 2007 season but the way in which the engine is used has changed greatly during the same period. For example, we have seen two reductions in maximum RPM, engine life has doubled, KERS was installed and removed, and refuelling has gone. These changes have been handled by "retuning" the engines and by allowing limited modifications. The engine suppliers have operated within these rules to develop the engines currently racing and, considering that the engines are all different, as are the internal constraints within the engineering teams, the outcome after a number of "open-loop" iterations is understandable.

Of course, characteristics of the engine other than its power contribute to the performance of the car teams. Driveability, heat rejection, weight and installed stiffness are significant, but overall car performance is most sensitive to engine power. Renault is committed to supply fully competitive engines and we are confident that this is possible within the current rules framework administered by the FIA, but we cannot be satisfied while the power of our engine remains significantly behind the best.

At the start of the season, there was much talk that an engine's fuel economy could play a decisive role in the no-refuelling era. Has that proved the case?
RW: Not to any meaningful extent. Engine fuel consumption is an important performance characteristic, second only to power, and the weight of fuel carried in the car is directly related to its fuel consumption. With no refuelling in 2010, this is more important during the race than in 2009, but the opposite is true in qualifying: in 2009, qualifying on the race-start fuel level, there was an opportunity to convert a fuel saving into a lap time advantage in qualifying. The effect is well understood and all competitors have worked to optimise performance in this area. Apart from operational errors, it would be an exaggeration to suggest that fuel consumption differences are decisive in 2010.

Earlier this year, much was made of requests for engine modifications that had been made by other engine suppliers. Can you explain the process by which this is done?
RW: The rules concerning changes to the specification of the homologated engine are remarkably simple. No changes to the homologated engine are permitted for any reason except with the prior approval of the FIA; hence the engine 'freeze' we commonly talk about.

This doesn't mean that the specification of the engines is completely static. These are very sophisticated engines operated at the limit of their performance and reliability envelope. The installation of the engine and its use evolve from year to year and the duty cycle becomes more severe as engine life increases and car performance improves. Each engine supplier may have legitimate reasons to request approval for such modifications, such as fixing reliability or quality problems or to manage changes in the supply chain. The requests take the form of an explanation of the reason for the proposed change, plus a description of the modification (including full drawings of any modified parts) and an assessment of the effects of the change.

Based on our experience, the FIA deals thoroughly with each request and, prior to approving any changes and in accordance with the Sporting Regulations, the FIA consults the other engine suppliers. It is a system that works well to manage changes that remain modest in scope and quantity relative to the complexity of these engines.

Under homologated engine regulations, where are the challenges for the engine suppliers?
RW: At Renault, our objective is to supply and operate engines capable of winning races and championships. This is a formidable challenge, independent of the restrictions on engine development, and the engine homologation regulations represent an additional constraint. To do so, we work closely with our chassis colleagues to maximise the performance of the Renault-powered cars.