Gearhead News

June 21, 2021
Here’s What Happens When You Spin a Tire Faster Than the Speed of Sound

Tires may all be black, round, and good for driving down a road, but beyond that, different tires are less alike than most people realize. Specialty vehicles like the Bugatti Chiron Super Sport 300+ need purpose-built tires reinforced with carbon fiber in order to crack 300 mph. Yet even those tires, despite costing thousands of dollars per corner, are only guaranteed safe up to a certain speed. What happens when you push a tire past that—way past that—like, beyond the sound barrier?

Russian YouTube channel Garage 54 figured it’d find out, which it did by building a custom rig to spin wheels at extreme speeds. The testing rig is assembled from a 2.5-liter Toyota V6 producing about 200 horsepower and 180 pound-feet of torque, which travel through an automatic transmission to a modified differential from a minivan. With an electronic throttle actuator installed to allow remote operation for safety’s sake, the rig was ready for testing.

YouTube | Garage 54
Tire approaching the speed of sound

Garage 54 took its creation to a nearby shooting range, where it mounted a 235/40R18 tire with the second-highest speed rating, Y, indicating tolerance of speeds up to 186 mph. Because early tests indicated the tire would warp enough at high speed to de-bead itself, they stuffed it with an inner tube to maintain its shape. Once installed, they ran the rig through its paces, achieving a maximum indicated output speed of 10,437 rpm before the tire exploded so quickly that even the slow-mo cameras couldn’t catch more than a frame of its carcass flying off-screen.

Given that tire size’s 79.8-inch circumference, we calculate that it reached a maximum road speed of 789 mph. While the speed of sound varies with altitude and temperature, it generally falls in the mid-upper 700s near sea level. So yes, they indeed broke the sonic barrier with a tire.

Their math, however, indicates a top speed of 1,332 kph, or 828 mph—they might have recorded a higher speed than shown on camera, or accounted for tire deformation that increased top speed. Whatever the true speed, we don’t disagree that they sent a tire supersonic, and in the process no doubt made the ghost of Chuck Yeager proud.

Got a tip or question for the author? You can reach them here: james@thedrive.com