A well placed source at BMW M in Garching recently tipped us to the idea that M is looking to introduce Electric Power Assisted Steering in the next M3, codenamed F80 and scheduled to launch as a sedan for model year 2014. According to this source; Porsche is being praised for the system in the new to market 991 which is EPAS, so why can ‘t M do the same in the M3? We also learned that BMW and Porsche are using ZF as the supplier for these systems. The steering tuning and algorithms would be manufacturer specific but the hardware would be similar if not identical.
There is some efficiency gains with EPAS systems because they, unlike traditional hydraulic offerings, do not draw engine power unless needed and 90% of all driving is done in a straight line where there is no need for power assistance. If the EPAS is not pulled at the last minute in favor of a traditional hydraulic system (as was rumored with the M5/M6) the electronic programming would need to have significantly more feel before the limit than BMW ‘s current EPAS offerings to keep critics to a minimum. In the US BMW uses EPAS in the latest 3,5, and 6 series models. The current BMW system dials in enough feel to allow the driver to make corrections but that is not communicated early enough in some situations- many bemoan the change.
We hope BMW will utilize a system that regulates the torque output of the electric assist rather than just dial down the power level as that seems to make all the difference in terms of feel.