SHANGHAI, China—As predicted by many—and wished for by the sport's organizers—tire choice is playing a key role in this season's Formula 1 World Championship.
When it took over this year as F1's sole race tire supplier, Pirelli Tyre S.p.A. was tasked by the Federation Internationale de l'Automobile to produce a wider range of tire choices in the hope of adding an element of uncertainty to the proceedings.
Pirelli appears to have succeeded, based on the results of the season's first three races—especially the most recent, the Chinese Grand Prix.
Race winner Lewis Hamilton and runner-up Sebastian Vettel both acknowledged that Hamilton's decision to change tires three times during the 200 mile race trumped Vettel's team's choice of two stops, as Hamilton was able to chase down and pass Vettel in the race's closing laps, despite the additional time spent on the extra pit stop.
Third place finisher Mark Webber used four tire changes while moving from his 18th starting spot.
Pirelli supplies each team at each race with two tire choices: one harder compound and one softer. Teams must use at least one set of each tire type during a race.
Some racing purists argue this is creating artificial competition, but the FIA has been experimenting with a number of performance factors the past few years to provide teams with strategic choices.
One aspect of the tire performance issue Pirelli has pledged to address is the tendency of its softer compounds to degrade under severe use and start shedding bits of rubber known in racing circles as “marbles.”
Tire marbles have been part of racing for decades and are often considered a nuisance, gathering on the track outside of the ideal racing line and posing a hazard for competitors who attempt to pass by getting “off line.”
In Pirelli's case, however, a number of drivers complained after the Malaysia Grand Prix April 10 that the marbles had turned to bullets that were sticking to their helmet visors.
A Formula 1 tire weighs about 19 pounds when new and can lose up to 15 percent of that—about 3.3 pounds—as it wears, Pirelli said. The wear can manifest itself in the form of marbles, which Pirelli describes as lumps having the shape and consistency of toffee, weighing up to three-fourths of an ounce on average.
“The races just seem to keep on getting better and better this year,” said Pirelli Motorsport Director Paul Hembery, who added, “…the people who had looked after their tires best took the top results.”