The Science Behind Ultra-High-Performance Tires

The Science Behind Ultra-High-Performance Tires

The dream of going fast began soon after the invention of gasoline-fueled vehicles in 1880. The first true race was held in 1895 from Paris to Bordeaux and back with a distance of 1,178 km (732 mi.) and average speed of 24.15 kph (15 mph). In the same year, the first 54-mile race from Chicago to Evanston and back happened in the USA. With just six cars, only two eventually were able to finish the race with an average speed of 7 mph.

In short, the world of vehicles and their components has come a long way since 1895. The technology behind racing trickled down to street vehicles and their parts. Today, street cars can reach speeds north of 300 mph. As a result, vehicle components must be able to perform at such a demanding speed. Obviously, the only part interacting between the road and vehicle is the tire, so we in the tire industry like to think that is the most important component of any vehicle. Not only do tires need to carry the desired high speed, but they also require managing handling, endurance, ride, noise and traction in various temperature and weather conditions.

When we started the “Science Behind” series in Tire Review, we discussed speed capability and speed rating.

Briefly, speed ratings were established to match the speed capability of tires with the top speed of the vehicles to which they are applied. Speed rating does not suggest the speed of the vehicle and only shows the maximum capability of the tire. With the expectation of the letter H, letters go from A toward Z as the speed capability of the tire increases. Tires with the letter Y are capable of speeds up to 186 mph. Anything above 186 mph is indicated with a Y bracket “(Y)”. On most tires with speed symbols of Y and (Y), tire sizing normally changes from R to ZR indicating higher speed capability.

A world of trade-offs restricts tire engineers from developing all the performance aspects at the highest level into one tire. Like vehicles, tires are divided into different segments based on customer/vehicle requirements.

Here, we’ll review tire segmentation and its connection to vehicle segments. We’ll also examine performance requirements in each segment and the science behind developing an ultra-high performance (UHP) tire.

Passenger Tire Segmentations

Different customers have different needs. While some are looking to have fast cars with fast tires, others may want a comfortable ride or a low-cost daily driver with a lowest operating cost. Vehicle segmentation was created to develop vehicles based on specific customer needs at different price ranges. As a result, tires were categorized to match vehicle segmentations.

Table 1 shows tire segmentation, typical tire use in the segment and examples of cars and tires. Note that there is not a standard for naming vehicle and tire segments, and companies may have different ways of segmenting the market.

Table 2 looks at the performance priority of each segment. As shown, tire expectations between a touring tire and a UHP tire are completely different. A UHP tire focuses mainly on the performance aspect of traction/handling, while the touring tire focuses on ride and wear.

The Science Behind Designing a UHP Tire

UHP customers are demanding. They pay the premium price for their vehicles and expect the vehicle parts to perform at the highest level, including tires.

The performance expectation is generally categorized into two categories of basic and additional performance.

First off, tires need to meet the basic expectation. They need to fit into the wheel, fit into the car, stay on the wheel, carry the load, have durability and perform at a high-speed level without signs of deterioration or separation. Table 3 outlines the minimum basic tests and performance a tire should meet (this also depends on the tire company).

Type of TestDetails
Tire MarkingDOT, ID (TIN), snowflake and any other markings
Tread Wear indicatorNumber of indicators and location
Tire DimensionOverall width, section width, outside diameter
Tire Bead Unseating ResistanceThe amount of force required to unseat the bead
Tire StrengthAmount of energy required to break through the belt
Tire EnduranceTo assure durability throughout the life of the tire
Low Inflation Pressure PerformanceTo assure tire performance at lower pressure
High-Speed PerformanceTo assure tire integrity at the required speed
Table 3: Minimum Basic Tests

For a UHP tire to perform at all the basic tests, the following specific designs are often implemented:

  • UHP tires often have a lower tread depth. While this is not ideal for tire longevity (wear) or snow performance, it helps the tire to perform at a higher speed by reducing heat buildup inside of the tire. In comparison to UHP summer tires, all-season tires have a deeper tread depth. This is due to their additional requirement of longer wear and performance in snow.
  • UHP tires have softer/stickier compounds. This allows the tires to create maximum traction with the road. As UHP summer tires do not need to perform in snow, they run on a stickier/softer compound compared to all-season tires.
  • UHP tires typically use rayon instead of polyester, in order to perform at higher speeds,. Rayon is a fabric made from purified cellulose fibers, which are typically created from wood pulp. The combination of properties such as high dimensional stability, good dynamic performance and very good thermal resistance makes it the best choice for use in the carcass of UHP tires.

Additional Performance

Once tires meet all required basic performance, it’s ready to hit the market, right?  No. Tires need to perform on a lot more criteria than basic expectations. Table 4 shows the typical performance expectations of a UHP tire.

Type of TestDetails
Wet Traction/Braking AND
Dry Traction/Braking
Vehicle with ABS: braking is the important factor compared to traditional traction. Often braking correlates to vehicle safety
Snow TractionNot applicable for UHP summer tires. Important performance on UHP all-season tires.
Ride/ComfortLevel of comfort for driver and passenger inside the vehicle
HandlingHow well vehicle responds to driver steering input
Indoor/Outdoor NoiseLevel of noise inside vehicle. Also, level of noise pollution
Rolling ResistanceLink to vehicle fuel efficiency
WearTire longevity which links to the mileage warranty
Table 4: Typical Additional Performance

For a UHP tire to perform at the highest level, specific designs are often implemented. We talked about how UHP tires often have lower tread depth, which helps the tire to have better overall handling and dry stopping distance. Below are a few other additional performances that fine-tune a tire to fit the UHP summer category.

  1. UHP tires often use a very high level of silica in their tread compounds. Additional silica improves wet braking performance without a significant trade-off on wear. When it comes to rubber composition, a summer tire has a physical compound that is intended for temperatures generally above 40°F. Summer tires tend to have the stickiest compounds among the three tire types, giving them the most grip and best braking performance on wet/dry surfaces. But in colder temperatures, a summer tire’s compound may begin to harden and lose traction, increasing the risk of slipping or skidding on the road surface. The rubber composition of the all-season tire generally splits the difference between a winter tire and a summer tire, so it can remain relatively flexible in freezing temperatures and also provide the rigidity to be effective in warmer climates.
  2. For precise handling, the majority of UHP tires use a very small apex (bead reinforcement) along with a stronger sidewall. This will allow the tire and rim to act as one piece and provide precise handling for the car. Some OE tires use steel reinforcement in the lower part of the sidewall for additional handling performance.
  3. UHP summer tires use a much more rigid tread pattern compared to UHP all-season. This allows the UHP summer tires to achieve the highest level of dry braking for a passenger-type tire. As UHP all-season tires still need to perform in snowy conditions, their pattern still requires sipes. Picture 1 shows a typical UHP all-season and a typical summer tire.
Science-of-UHP-Tires-Picture-1-1400
Picture 1: A UHP All-Season Tire (Left) vs. to a UHP Summer Tire (Right) Photos courtesy of Yokohama Tire)

The Evolution of UHP Summer Tires

While UHP tires are not new in the market, the technology has significantly improved. UHP all-season tires are a solid choice for the best UHP cars in the market. With advanced ABS systems, summer tires are able to deliver the shortest stopping distance generation after generation. How much more tire engineers can push the boundary is unknown, but this is not the last challenge in front of them. As the vehicle landscape changes, other new challenges will surface. One thing is for sure, tire engineers will always find a solution to move forward.

You May Also Like

Turbo Wholesale Tires launches Lexani Volt-EC EV tire

The company said these ultra-low rolling resistance tires help extend the range in EVs while performing well in wet weather conditions.

Turbo-Wholesale-Tires-open-house-volec-ev-lexani

Through its proprietary brand Lexani Tires, Turbo Wholesale Tires launched the new Volt-EC EV tire with vehicles like the Tesla Model 3, Ford Mustang Mach-E, Toyota Prius and Chevy Volt in mind. The company said these ultra-low rolling resistance tires help extend the range in electric vehicles while performing well in wet weather conditions. The design ensures a quiet and comfortable ride with over 20 tire sizes to choose from all backed by a 40,000 mile warranty, Turbo said.

TGI brings Duramás radial truck tires to the U.S. market

The company says Duramás TBR tires have been tested in countries where overloading and poor road conditions are the norm.

TGI-Duramas-radial-tires
Ralson Tire North America debuts RTR71 commercial truck tire

The RTR71 is built tough for spread axle trailer use, and features a robust casing design to resist cuts and chips.

Ralson-RTR71
Yokohama to supply Advan Sport V107 tires for BMW X7 SAV

The 22-inch size tires for the BMW XM are supplied with either performance or high-performance specifications.

Advan-Sport-V107
Last-mile delivery demand continues to grow, boosting the tire market

Tire dealers are in an ideal position to grow their commercial business and increase profits.

light-duty-last-mile-1400

Other Posts

How Phaelona Bradley champions customer service and breaks barriers

Phaelona’s commitment to making those around her better and improving customer relationships is helping to shape a customer-centric culture at Yokohama.

3633-Phaelona bradley
GRI adds 11 SKUs to agriculture and construction tire segments

The expanded portfolio includes tires for implement and flotation machinery in agriculture and skid steers in the construction category.

GRI-combo
New Continental whitepaper gives insight into tire testing

The Continental whitepaper also sheds light on the development and use of current test methods for the manufacturer.

Continental-Americas-HQ-Sign-1400
EV tire market evolves to meet driver demands

Dedicated EV replacement tires are optimized for range, tread life and reduced road noise.

Bridgestone-Turanza-EV_Hero-Image