Teams signal opposition to 18-inch wheels

The proposal to move to larger 18-inch wheels has come up against opposition from leading teams since it is not considered 'an attractive direction in terms of performance'.

With Pirelli's current contract as control tyre supplier in F1 concluding at the end of the 2016 season, the tender has been opened up to a potential alternative, with Michelin airing its tentative interest on the condition that it can tinker with the current formula.

Part of its plans include an increase in size to accommodate 18-inch rims, a proposal motivated by the desire to ensure its tyre supply offers greater relevance to road car development, while Pirelli also signalled its intentions by revealing its own 18-inch shod GP2 car in Monaco.

However, both companies may be forced into a rethink following a fairly lukewarm response to its ideas from a handful of teams, who suggest the move will result in lower grip and create fundamental issues with chassis design.

"I think the broad consensus is that going to bigger wheels is not a good direction," said Mercedes' Paddy Lowe. "Certainly from a grip point of view it's not positive. Like for like, such tyres will have a lower grip and the weight will go up considerably so it's not an attractive direction performance-wise, so I think generally we would intend to stick with the 13 inch wheels."

It was a view shared by McLaren's Matt Morris, who said simply changing the configuration of the tyres would have a substantial effect on the design of the car.

"It's not just the tyre size, it's all the other parts that change with that, all the brake internals and what have you. From our side, we relish change as any engineer does so yeah, if that is going to change, we have a great knack of finding the best way around it and then potentially it's an area where if you do a good job you can be competitive, so we're happy if that was to go ahead."

James Allison, meanwhile, says that while he is not entirely against the idea of a change in tyre size, he says a decision must be taken sooner rather than later.

"We're discussing what that ought to be along with all the other aspects of the rules for around about that time. I would say that sooner the better would be good for things like that. Tyres are maybe the most complicated bit of the car and the bit of the car that we have the least data about.

"We're not allowed, by regulation, to test them, either on the track or off the track, so we have the data provided by the tyre manufacturer but that's all and you want that information good and early when you're designing a car.

"Not just for the vehicle dynamics part of the car but also tyres are one of the biggest aerodynamic components on the car and so having in your wind tunnel tyres of the appropriate shape, size and squashiness is a big deal. So sooner the better from our point of view but there's still time from where we are today. So as long as we get on with it from here it will be fine."