This article is from the Motorsport FAQ, by A H Henry bspahh@midge.bath.ac.uk with numerous contributions by others.
IndyCar racing tyres are Goodyear Racing Eagles, weighing 16.29
pounds, depending on whether they are rain or dry tyres, and whether
the tyre is for the front or back of the car. The tires have a rim
diameter of 15 inches and are either 10 inches wide (for the
`undriven' tire) or 14 inches (for the `driven' tyre). The cars are
limited to two-wheel drive, with the choice of front or rear-wheel
drive being optional. Teams are limited to 28 tyres per event at
short ovals and road courses, and 44 tyres per event at 500 mile
events.
 
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