The new Corvette Z06 is shaping up to be one of the finest supercars to ever come out of the U.S. and an intriguing new detail about it has emerged.

A handful of Corvette Z06 prototypes have been snapped testing in recent months and, as noted by Corvette Blogger, many people have commented on the massive rear tires being worn by prototypes. Now we know just how wide these tires are.

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One Corvette enthusiast was able to snap a photo of the car’s rear tires, discovering that they are Michelin Pilot Sport Cup 2 Rs measuring 345/25ZR 21. These are the same tires as used by the Porsche 911 GT2 RS and in all likelihood, the Corvette Z06 will get a bespoke compound co-developed with Michelin.

To put this tire size into perspective, the C7-generation Corvette ZR1 rocked 335 mm tires at the rear. Heck, even the massive rear tires used by the Lamborghini Aventador are ‘only’ 335s while the rear tires of the Bugatti Chiron are a staggering 355 mm.

Much like the C8.R, the new C8 Corvette Z06 will feature a 5.5-liter naturally-aspirated V8 with a flat-plane crank potentially producing as much as 625 hp and 480 lb-ft (651 Nm) of torque. This engine will rev to 9,000 rpm and could prove to be one of Chevrolet’s final naturally aspirated V8s.