Formula 1 raced in Spain this past weekend. The Barcelona-Catalunya circuit is one of F1's purpose-built race tracks, with a number of fast corners and a track surface that's more abrasive than usual. That means downforce is the name of the game. Catalunya has always required good aerodynamics, but it's doubly important now. The more speed you can carry through a corner, the less energy you have to add on the following straight, and energy management is now as important in F1 as it is at Le Mans or in Formula E or even IndyCar. And the more downforce you have, the less the car slides, and the less the car slides, the less the tires get eaten up.
It's the tire wear that suggested the strategies. So far, all the races this season have been one-stop affairs as drivers make their required change from one tire compound to another. But 66 laps of Catalunya would require at least three sets of Pirelli tires to get to the end. Maybe even four. As the tires wear, they become slower, to the tune of 0.2–0.3 seconds per lap. And one way to exploit that is with an "undercut"—pit early, change onto fresh rubber, and make use of the tire offset against your rivals to put in fast laps while they're losing time. Do it right, and when they make their next pit stop, you should be in front.
Splitting the race into four stints means one more pit stop, and it costs about 22 seconds to drive through the pit lane, stop in the box, and then exit the pit lane again, assuming a tire change in less than three seconds. But since each set of tires is needed for fewer laps, they can be worked hard enough to offset that 22-second pit stop and more.
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