TOWCESTER, England (July 7, 2014) — The Formula 1 racing community will get a preview this week of what the future of the sport might look like in a few years when Lotus F1 Team will test 18-inch rim diameter tires that supplier Pirelli Tyre S.p.A. is proposing.
The change is a drastic one — moving from the current 13-inch configuration — but one Pirelli claims would lead to increased technology transfer between Formula 1 racing and road-going tires.
Pirelli claims moving to an 18-inch tire would provide performance advantages such as increased rigidity through less sidewall flexibility—although this could have an effect on car design since sidewall flexing plays an important part of the current Formula 1 car’s suspension and damping.
Pirelli calls the 13-inch configuration — a size that’s been standard for the past few decades — “no longer relevant” in the general marketplace, where the standard OE fitment is edging steadily toward 18 inches.
From the tire maker’s point of view, Pirelli said a smaller sidewall would lead to drastically reduced branding space and could present manufacturing challenges.
Pirelli’s motorsport director Paul Hembery pointed out that many other motorsport series already use larger rim-size tires.
“In order to underline F1’s role as a test bed for future mobility solutions,” Mr. Hembery said, “we believe that it benefits everybody to have as close a link between road car tires and competition tires as possible….”
He also stressed any change would have to be approved by Formula 1 and the F1 teams and this proposal is designed to “help teams and drivers make the most out of the equipment, regulations and resources they have at their disposal….”
The tire maker suggested moving the tire designation to 18 inches as long ago as 2010, when it first took over the F1 spec tire contract.
The tires being used in 2014 are 245/65R13 and 325/50R13 front and rear, respectively, with an outside diameter of 660 mm for dry weather tires and 670 mm wet, according to Pirelli. Moving to an 18-inch rim diameter would yield 35 to 40 series fitments, provided the outside diameter doesn't change.
The Lotus F1 Team test is scheduled to take place July 9 at Silverstone Circuit near Towcester, where the British Grand Prix was held July 6.