Having quit F1 as an engine supplier at the end of 1997, Renault soon wanted back in, but in a way that would deliver much greater marketing collateral. That chance arose with an option to buy the fading Benetton team in 2000, but success didn’t come as quickly as expected, partly due to the dominance of Michael Schumacher and Ferrari, and partly through Renault’s own follies, such as the flawed ultra-wide-angle V10 engine concept they persisted with until 2003.
Under the bravura technical leadership of Mike Gascoyne, they produced interesting cars under a then-unusual methodology: two separate design teams operated in parallel, sharing experience and data during the racing season, and producing cars in alternate years.
Even before the wraps had been taken off 2004’s R24, designed by a team led by ex-jordan man Mark Smith, another team under the auspices of Tim Densham had begun work on the R25 for 2005. By the time it was ready to run, Renault were already part of the chasing pack behind Ferrari – sometimes poaching wins.
The secret of Renault’s success was the ongoing tyre war between Bridgestone and Michelin, and the lessons learned during a failed experiment with the wide-angle-vee engine. Where Bridgestone were hand-in-glove with Ferrari, so too were Michelin and Renault. And while the wide-angle-vee engine was a flop due to unreliability and poor balance, Renault’s engine department learned a lot about maximising usable torque and fuel efficiency with a low-rev ceiling – useful since the FIA demanded engines should last for two race weekends in 2005. Similarly, designers found that the pain of adapting to the ever-growing weight of the wideangle engine (as Viry tried to make it more reliable) brought gains further down the line.
The R25 had a more rearward weight balance than many rivals, which gave better traction and negated some problems caused by the latest aero restrictions from the FIA. It took the undercutsidepod philosophy first seen on the R24 (and still de rigueur in F1 now) to greater extremes, slant-mounting the radiators to maximise surface area in a space with a smaller profile.
For 2005 the FIA banned tyre changes and Bridgestone adapted poorly, leaving Ferrari in the doldrums. Renault and Mclaren won eight races each, but Renault’s better reliability handed them drivers’ and constructors’ titles. Carbon-fibre composite monocoque Double wishbones, pushrod actuated torsion bars and damper, front and rear Renault RS25 V10 3,000cc 800+bhp Renault 6-speed semi-automatic 605kg 3,100mm Michelin Fernando Alonso, Giancarlo Fisichella Bob Bell, Tim Densham