Conti pushing hybrid, electric car tires to next level

HANNOVER, Germany (July 7, 2014) — Continental A.G. is taking development of its Conti.eContact line of tires for hybrid and electrical vehicles to the next level, designing separate tires for the specific needs of hybrids vs. electrical vehicles.

Originally launched in 2011, the eContact line was designed to deliver markedly reduced rolling resistance to help extend the range of vehicles dependent on electrical charges, the company said.

As more fully electric vehicles are starting to become available, Conti now is fine-tuning the concept to the distinct needs of the EVs vs. hybrids, the company said in a recent briefing on the subject.

In a nutshell, Conti said hybrid vehicles need tires with opitimized rolling resistance that can also deliver high-speed performance, while EVs require “significantly” better rolling resistance along with reduced noise generation but without the need for high-speed characteristics.

In Europe, where the number of hybrids and EVs exceeds that in North America, Conti has initiated low-volume production at its plant in Sarreguemines, France, of the eContact for hybrids in six sizes for 17- and 18-inch rims. Conti said the eContact is produced on a specialized production line within the plant that requires certain steps be done manually.

Conti estimates that hybrids and EVs each represented 1 percent of the 67 million vehicles in operation in 2010. These shares should go to 3 and 2 percent, respectively, by 2015 and 8 and 3 percent by 2020, Conti said.

The tire maker claims the rolling resistance of this eContact model is 20-percent lower than a conventional tire's rolling resistance while delivering wet and dry braking and handling performance similar to that of a normal car tire. This is made possible by a combination of advances in compounding and production.

Among the specialized technologies in play for the eContact line are “Green Chili” rubber compounding, hydro-siping, “AeroFlex” sidewall sculpting and the tire maker's ContiSilent noise-suppression system.

• The Green Chili concept employs an elevated silica content and the use of unidentified “specfic grip additives” to reduce internal friction of the polymer/reinforcement matrix in an effort to improve grip while reducing rolling resistance.
• HydroSipes are “double-arranged” surface drainage sipes for an optimized “wiper” effect, designed to reduce wet braking distances and improve wet handling.
• AeroFlex design produces a smoother, more flexible and lighter-weight sidewall for reduced air turbulence and energy loss from deflection.
• ContiSilent is the attempt to cut a tire's interior noise generation by attaching a strip of polyurethane foam to the inner liner under the tread area.

Conti is rolling out the product this summer in Europe in six sizes — 215/55R17 98VXL; 225/50R17 98VXL; 225/55R17 101WXL; 235/50R18 101VXL; 235/60R18 107VXL; and 255/55R18 109WXL — specially designed for models such as the Opel Ampera, BMW 5 ActiveHybrid, Lexus LS 600h and Porsche Cayenne S Hybrid, as well as other cars and SUVs with hybrid drive.

There are no plans for now to offer it in North America, Continental Tire the Americas L.L.C. said.