TOKYO (March 4, 2009)—Bridgestone Corp. plans to introduce later this year a third-generation run-flat tire concept it claims will offer a smoother ride and cooler operating temperatures than current generation run-flats.
Bridgestone intends to market the new tires primarily to vehicle makers for OE fitment on new cars, SUVs and light trucks to take advantage of the car makers' increasing development of lighter, smaller, more fuel-efficient vehicles.
The company said it is confident its new design will entice car makers to take a fresh look at run-flats and their potential contribution to safer and more environmentally friendly transportation choices. Using run-flats, Bridgestone said, potentially could eliminate 59 million spare tires annually, reducing by more than 2 million tons the amount of CO2 generated in the production of those tires and wheels.
To improve riding comfort and durability, Bridgestone is using three technologies:
* Use of “NanoPro-Tech” rubber—involving improved dispersion of carbon black in the compound— in the sidewalls; this compound reduces the friction that occurs between carbon molecules when tire is loaded, and therefore reduces heat generation by about half when the tire is driven with no air pressure.
* Making the body plies with a “leading-edge” fiber that shrinks with heat, thereby curbing deformation of the tire sidewall and preventing a rapid increase in temperature. Bridgestone did not identify the type of fiber being used.
* Use of “cooling fin” technology—protrusions on the surface of sidewalls that create disturbances in the airflow and thereby cool tires.