In general, various resistance such as rolling resistance of tires, aero-dynamic resistance and so on are acting on a vehicle against its motion. Reducing these resistance will allow a vehicle to move with less energy and thus improve fuel efficiency.
Rolling resistance on tires is a force that acts against a vehicle’s traveling direction. It is primarily caused by the deformation of the tires while rolling. For instance, assume you are pedaling a bicycle; If the air pressure in the tires was low, you would have to exercise greater power on the pedals in order to move forward. This is because the rolling resistance on the tires is enhanced due to its increased deformation.

The Bridgestone Group’s fuel-efficient tire technology, named “ologic,” produces superior fuel efficiency with the following two features:

(1) Large tire diameter and high inflation pressure to significantly mitigate deformation of a tire in contact with the road surface and thus reduce rolling resistance
(2) Narrow tire width to reduce aero-dynamic resistance, which is an important factor in the improvement of a vehicle’s fuel efficiency

In addition, by optimizing rubbers and other materials of reinforcement layers, tire structures and tread patterns, a 30% reduction of rolling resistance coefficient along with a 10 % improvement of braking on wet road has been achieved compared with a conventional tire. (*1)

• *1Based on a comparison between a tire with the ologic technology (tire size: 155/70R19, inflation pressure: 320kPa) and a conventional tire with an equivalent load capacity (tire size: 175/65R15, inflation pressure: 210kPa).

“ECOPIA with ologic,” tires with the ologic technology have also high grip on both wet and dry road conditions by adopting the combination of exclusive tread patterns and compounds. The technology has been adopted in BMW’s evolutionary i3 electric vehicle as well as solar cars that compete in an international solar car race, the Bridgestone World Solar Challenge.
The Bridgestone Group will continue its longstanding commitment to reduce CO2 emission through improving vehicle fuel efficiency by developing a wide range of technologies, thereby bringing a sustainable society into reality.