This situation relates to the nature of F1 racing — because of the sport's knock-out qualifying procedures, the need to supply wet weather tires regardless of weather and cars that didn't finish races meant 61.5 percent of tires supplied were not used.
Of the 12,920 rain or intermediate tires supplied, just 10 percent were used.
On average, each tire used on race weekends ran 43 miles. F1 races typically run 200 miles, but in qualifying some tires are used for just a couple of laps, and this also takes into account cars that either crashed or fell victim to mechanical failure and thus did not complete a full competition stint.
Pirelli also supplied 5,268 tires for testing purposes. Pirelli, which has the exclusive tire supply contract through 2019, said it collects and reclaims all of its F1 tires, used and unused.
Due to rule changes to the car configuration — larger wings and higher downforce — the Federation International de l'Automobile revamped the tire regulations to allow tires to be up to 25-percent wider to deal with the increased downforce and provide more grip.
These changes led to a "record-breaking" season, according to Mario Isola, head of car racing for Pirelli. The pole position time last season, for example, was on average 2.45 seconds faster than in 2016, and the fastest race lap was on average 2.97 seconds quicker.
For 2018, Pirelli is increasing the number of options again, to seven slick versions and one wet and one intermediate version.