Pirelli's desire to introduce bigger tyres to F1 took another step towards reality during last week's Silverstone group test, as Lotus ran the 18-inch creations on a hastily-modified E22.
The tyre manufacturer's Paul Hembery is quick to point out that the 13-inch rubber currently in use in F1 is 'no longer relevant to the everyday road user', but admits that 18-inch tyres would be a big step for F1, even if other motorsport series have already adopted the bigger size.
Lotus technical director Nick Chester was interested to see what difference the bigger wheels and tyres made to the current breed of F1 car, but revealed a number of changes had to be made to the E22 to accommodate the latest concept.
“The 18-inch Pirelli tyres are obviously very different to the tyres used in F1 now, so we viewed it as a shakedown run; simply a case of 'let's see' for Pirelli, rather than a performance run,” he confirmed, “The bigger size meant we had to trim the floor and change the ride height to adapt to the different loaded radius of the tyres. Some of the suspension set up also had to be modified, such as the cambers, [but] these were very basic revisions to enable Pirelli to evaluate the concept for the future and see what the bigger wheels look like on the car.”
Should the powers-that-be conclude that it would be a good idea to move another aspect of the sport closer to commercial motoring, Chester admits that the teams would need a decent lead time to be able to design and tune their cars for the new tyres.
“Having 18-inch tyres would have a big impact on design,” he insisted, “We would want to be testing in the wind tunnel for at least a year ahead of their introduction. The ride height and suspension packages would have to be changed and the tyre profile itself would be very different. But it would be an interesting challenge.”