A rhythmical acceleration sound to match the driver’s sensory experience
The e:HEV two-motor hybrid system is predominantly driven by an electric motor, with electricity generated by the engine. Linear Shift Control takes advantage of this characteristic to synchronize vehicle speed with engine sound. By controlling engine speed in steps to match the increasing vehicle speed, Linear Shift Control realizes a rhythmical engine sound like gear changing in a stepped transmission. There is a sense of coherence between speed progression and engine sound that makes stepping on the accelerator an exhilarating experience in situations like accelerating from standstill at an intersection or merging or overtaking on an expressway.
Electricity generation efficiency unaffected by engine speed control
Except during high-speed cruising, when the engine drives the vehicle, an e:HEV system operates as a series hybrid, with the engine generating electricity and the electric motor driving the vehicle.
Series hybrids generate electricity consistently within an efficient engine speed range. In earlier models, however, the engine speed was sometimes at odds with the driver’s own perceptions—not really adjusting to the degree of accelerator application, at times running faster than it should for the acceleration. Linear Shift Control adjusts engine speed to match the degree of accelerator application and the speed of the vehicle while maintaining excellent electricity generation efficiency. The result is a satisfying engine sound that makes it seem the engine is driving the vehicle, when in fact it is the motor driving.
Linear Shift Control characteristics
Linear Shift Control enabled by high-efficiency combustion technology
Linear Shift Control actively harnesses torque direction to employ a wider
engine load range than conventional control. This means that to also achieve
fuel efficiency, the engine requires a wider high-efficiency operating
range.
Honda fills that requirement with a 2.0-liter direct-injection
Atkinson-cycle DOHC engine designed for the e:HEV system. Compared to
earlier engines, the high efficiency operating range has been dramatically
expanded by using a multi-stage, high-pressure direct injection system and
realizing a high compression ratio, as well as through homogenization of the
air-fuel mixture using a powerful tumbling airflow, the use of split
injection during intake and compression phases to reduce knocking, and the
use of large-volume cooled exhaust gas recirculation (EGR).
Freedom in engine speed control has been enhanced as a result, enabling
appreciation of a rhythmical acceleration sound with Linear Shift Control.
Expanded high-efficiency operating range
An integrated experience adds to the elation of acceleration
Other features enhance the elation that Linear Shift Control brings to acceleration with a rhythmical engine sound. Active Sound Control*, which amplifies engine sound in Sport mode, and a Power Meter* synchronized with engine speed also help to inundate the auditory and visual senses with the vehicle’s surge of power.
*May not apply to some models
