Driving Dynamics and Rolling Resistance Tire Design Trade-Off 2019-01-5088
The main challenge facing the automotive passenger car industry for the next decade is CO2 emission reduction. The approach towards achieving conformity with stricter regulations is based on two main enablers: by means of powertrain improvement and energy demand reduction, adopting a low rolling resistance (RR) tire without decreasing driving dynamics.
The trade-off between RR and driving dynamics can be managed by means of the trade-off between the tread shore hardness (TSH) and belt angle inclination (BAI) of the tire. Based on current tire production, four submission tires have been produced with different combinations of TSH and BAI, both RR and/or driving dynamics oriented. In total five submission tires have been tested and evaluated in terms of RR, subjective handling and ride, objective handling, and braking.
In a multibody environment with the statistical Signal-to-Noise (S/N ratio) method, the correlation between vehicle performance, objective handling, and tire carpet, flat track measurements has been identified. The flat track method has been used to characterize tire carpet for the simulation model and to identify relevant tire-specific synthesis parameters as well. The carpets used for virtual tests show consistent results with objective experimental data. Hence it has successfully identified which of the carpet tire parameters was directly related to vehicle performances.
In summary, the effects of tire TSH and BAI on the trade-off between driving dynamics and RR have been demonstrated. The S/N ratio method has correlated the tire flat track measurement to vehicle performance.
A new original equipment manufacturer (OEM) vehicle development methodology, together with tire supplier know-how, allows improved achievement of the European Union (EU) emission regulations, satisfying vehicle market stability and controllability requests.