Tire sizes are regulated by several international certifications and standard bodies, namely the ETRTO (European Tire and Rim Technical Organization), the International Standards Organization (ISO), the German Institute for Standardization (DIN), and the Department of Transportation in the U.S.A (DOT).
The standard methodology for measuring the tire width is to measure from the outer sidewalls and not the effective contact surface of the tire. The contact surface on a slick may appear wider than on a road tire, but both tire widths are the same measurement from the outside of the sidewalls.
The tires size designation is governed by international conventions and is binding on all tire manufacturers. The tire approval authorities in each market will homologate, approve the tire for use according to the same international norms. Let’s look at these standards in more detail.
How Must Tire Widths Be Measured?
The nominal width of a tire must be measured on an inflated tire (operating pressure) in an unloaded state. The measurement must represent the maximum distance of the outer sidewalls of the tire. Tires may appear wider based on the amount of contact surface to the road or due to the deformation of the tire when fitted to the vehicle.
Appearance can be deceiving, and tires should not be measured and judged in a state of installation. Tires are designed for specific purposes and, as such, have different tread patterns and rubber compound hardness. Racing tires are made of very soft rubber compounds and have very little or no tread pattern.
When installed on a car, the racing slicks will compress more and appear to be wider than a set of standard road use tires of the same tire dimensions. When measured off the car but fitted to the rims and inflated to operational pressure, both the racing slick and the road tire will have the same nominal width.
Measuring the tire width accurately for the purpose of certification, a Vernier caliper is used. The caliper jaws must be long enough to extend past the entire sidewall width of the tire. The width of the tire is then measured in millimeters from the outermost bulge of each sidewall. The tire must be mounted on a rim and inflated to operational pressure for the purpose of dimensional measurement.
Do Continental Brand Tires Run Wide When Cornering?
Continental Tire has a history steeped in motorsport and has been developing and producing tires since 1871. The company has manufacturing location in Europe, North America, China, Russia and are renowned as a premium tire manufacturer. The Continental brand is specified as Original Equipment fitment on most European and U.S. performance brand cars and trucks.
Running wide is a racing term describing that happens when a race car leaves the road during cornering and the tires lose grip, causing the car to run off the track or wide onto the apron of the race track. Continental brand tires are known for excellent road holding.
The Continental Sport Contact and Continental Premium Contact range of tires are designed for excellent grip and accurate cornering ability. The Black Chili tire compound is a secret trademarked rubber used on the tire treads of the Continental tires.
Tires are rated for performance by independent tire testing authorities in all major markets, and Continental brand tires always rank in the top ten and most often in the top three tire brands. Michelin is consistently rated as the top tire brand globally, with Continental, Bridgestone, and Yokohama also ranked as top contenders.
Wide cornering reflects the driver’s skill more than the tire as the driver should establish the cornering ability of the tires based on their wear condition during the race. If the tires become worn late in a race, the driver needs to adjust the speed when cornering or go to the pits for a fresh set of tires.
How Does Tire Width Affect Driving Performance?
The main function of the tires is to provide grip to the surface of the road and thus assist the steering and control systems of the car is performing optimally. The contact surface of a tire is the patch of the tire in contact with the road surface. The wider the tire, the larger the contact patch will be, resulting in better grip and control of the car.
Wide tires help to disperse the mass of the car over a larger area enabling the driver to have more control of the car. When braking, the tires need to slow down the rotation of the tires by gripping and sliding on the surface of the road. If the tire starts to skid, it is due to the loss of grip between the tire and the road surface.
Racing drivers developed a technique called percussive braking, where short successive braking was found to be more effective in slowing the car down than constant braking. This technique led to the development of Anti-Skid Braking Systems (ABS), where the braking system performs several bursts of braking, thus preventing the tires from locking up into a skid.
Conclusion
The Continental tire brand is highly regarded and often the first choice for fitment by car manufacturers or performance racing drivers. The term running wide in motor racing parlance means that a driver loses control of the vehicle and goes off the race track. There is no evidence that the Continental tire brand exhibits this type of behavior.
The tire width measurement is a standardized technique to establish the distance between the outer sidewalls of a tire. The tire must be mounted on a rim and inflated to the normal operating pressure when the width is measured.
Tires may appear wider when fitted on a car due to the type of tire tread and the hardness of the rubber compound used for the sidewalls and tread surfaces. A racing slick tire will have a larger contact surface to the road surface than a standard production tire but still have the same nominal tire width.
