It's easy to take tires for granted. We rarely interact with them, and usually only come down to their level when it's time to check and add air. So it's no surprise that some see tires only as rolling rubber hoops, built for laying tracks and doing donuts.
But the truth is, your tires may be the most high-tech component on your Corvette. And just as every new Vette is the pinnacle of user-friendly performance, the latest tires are the most reliable, most comfortable, and highest- performance versions in a long production history.
To drive home how lucky we are right now, put yourself in the shoes of a tire engineer: Ever since Charles Goodyear stumbled upon vulcanized rubber in 1839, engineers have been making trade-offs with tires. There are so many criteria working at cross purposes—traction, comfort, noise, wear, rolling resistance, handling—that compromise has always been a must. Remember those rock-hard "performance" tires that used to shake your fillings out?
But thanks to recent advancements in tire design and production, modern tires are able to lessen those compromises. For example, the 2014 Stingray's Michelin Pilot Super Sport ZPs carry a 300 treadwear rating, higher than many recent Corvette tires. Yet the Stingray pulls more than 1g in lateral acceleration, has less rolling resistance (for improved fuel efficiency), and rides both smoothly and quietly. That, my friends, is called progress.
This article will help you learn more about tires—what they're made of, how they're assembled, how to read their sidewalls, and most importantly, how to take care of them.
PART 1: TIRE CONSTRUCTION
Tires are highly complex, multi-layer constructions that meld specialized rubber compounds with reinforcing materials. Here's what your performance tires are made of:
Tread is what hits the road, and each tire's tiny contact patch keeps your Corvette on it. It's made of a complex tread compound comprising rubber, along with other materials such as silica, carbon black, polymers, and bonding agents. Today's advanced tread compounding can make softer compounds rigid for high-performance applications—so it's no longer accurate to state that all high-grip tires are "soft" compounds, and long-life tires are "hard" compounds.
Tread patterns aren't just a cool design, they play a huge part in a tire's performance. They handle water removal, help handling, and reduce noise. The patterns can be asymmetric (not the same across the tread centerline) or directional (requiring a particular rotation).
A tire's tread incorporates a center rib and tread blocks that assist with dry handling, grooves that evacuate water, sipes that open and lock together to increase handling, and shoulders that can be square or rounded.
Sidewalls help support the load, protect the tire from curbs and other hazards, and, in the case of run-flats, help keep a deflated tire rolling. In addition to the obvious rubber outsides, sidewall internals include fabric carcass plies. They can also be reinforced with fabrics or steel cords to help steering response and cornering stability.
The bead allows the tire to be secured to a wheel. It looks like a smooth, U-shaped circle at the very bottom of a tire's sidewall, and it's internally reinforced by steel wires.
Cap plies—typically used on performance tires—are found right under the tread. These nylon layers control the shape and size of the contact patch during acceleration, braking, and cornering. They can also help smooth out the ride.
Steel belts form a foundation for the tread. Made of high-tensile steel, these belts provide tread stability, and guard against impacts and punctures.
Body plies/carcass plies are fabrics like polyester that help give the tire its shape. Modern body plies run radially at 90 degrees to the tire centerline—hence, the name "radial." In contrast, older or reproduction bias-ply tires run the plies at 45 degrees to the centerline.