Tetsuji Mino, president of Sumitomo Rubber
Tetsuji Mino, president of Sumitomo Rubber
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Sumitomo Rubber Industries Ltd unveiled its current tire technology development and visions on Feb 14, 2008.

In the talk, President Tetsuji Mino introduced the company's efforts to produce "tire made of 100% natural resources," "tire with a rolling resistance reduced by 50%" and "run-flat tire" capable of running even when it is punctured.

The company plans to promote the development of tire made of 100% natural resources in order to reduce the use of fossil fuel. Sumitomo Rubber released the ENASAVE ES801, a tire made of 70% non-fossil fuel resources in March 2006. The company will launch the ENASAVE 97 with the rate of non-fossil fuel resources increased to 97% in March 2008. But the remaining 3% is still dependent on fossil fuel.

"Relying on 3% fossil fuels is a major hurdle," Mino said. "I don't think we can make it in one or two years, but I'm determined to put the tire on the market even if it takes five to ten years."

The remaining 3% of fossil fuel is required for the antioxidant and the rubber accelerator used in the vulcanization process.

"With the current technology, they cannot be replaced by natural resources," said Takaki Nakano, the company's senior executive officer.

The company is also focused on the development of tire with a rolling resistance reduced by 50%, although the timeline for commercialization is yet to be decided. The tire will reportedly improve the fuel efficiency by approximately 10%.

The rolling resistance corresponds to the heat generated when pressure is applied to the tires at braking.

"Some part of the rolling resistance is caused by the friction between tires and the road required for deceleration, but the rest is generated by the thermal energy induced by other factors," Nakano said. "So, we are trying to minimize any unnecessary energy."

The company plans to ship 100,000 run-flat tires for Japanese auto manufacturers in 2008. Sumitomo Rubber's run-flat tires are used in Toyota Motor Corp's Lexus GS, Honda Motor Co Ltd's Acura, Nissan Motor Co Ltd's GT-R, etc.

Sumitomo Rubber provides its run-flat tires under the brand name of Dunlop in Europe. In 2008, the company is expecting to ship a total of 1 million pieces mainly for three vehicle lines from Bayerische Motoren Werke AG (BMW) of Germany.

"The tire used to be faced with a comfort issue," Mino said. "But now that it offers a riding comfort on par with that of a regular tire, an increasing number of auto manufacturers are using it."