Hybrid Drive
Lexus Hybrid Drive is now in its second generation following the arrival of the new luxury SUV the RX 450h last summer. The precise engine details, emissions and fuel economy of the new CT 200h have yet to be announced, however, the advances Lexus has already made in its hybrid drive technology will be apparent in its new model.
The full hybrid drive system combines a petrol-driven engine with a powerful electric motor. Unlike mild hybrids, which use supplementary electric motor power simply to boost the performance of the petrol engine, the CT 200h is a full series/parallel hybrid, capable of operation in both petrol and electric modes alone, or in a combination of both.
It combines the fuel efficiency and minimal emissions benefits of a series hybrid with the acceleration benefits of a parallel hybrid, while avoiding any of their respective disadvantages. As a result, optimum performance will be delivered by the CT 200h on a par with conventional powerplants with a larger cubic capacity, while returning fuel consumption and emissions figures comparable to those of much smaller engines.
The improvements to the second generation Lexus Hybrid Drive already in operation in the RX 450h include:
- Adoption of the Atkinson combustion cycle for improved fuel economy
- Cooled Exhaust Gas Recirculation ( EGR ) for improved fuel economy
- Exhaust Heat Recovery (EHR) for improved fuel economy
- Reduced hybrid transaxle friction losses for improved fuel economy
- AI-SHIFT control (Artificial Intelligence – SHIFT) for improved performance and drivability
- New Power Control Unit for improved performance and fuel economy
- Increased front and rear motor torque for improved performance
- Choice of driving modes for improved fuel economy
Lexus Hybrid Drive in Operation
In the course of any journey, Lexus's full hybrid system will operate in different modes to maximise the vehicle's overall efficiency. At rest, the engine stops automatically to conserve fuel. Under conditions of low engine efficiency, such as at start-up or low to mid-range speeds, the vehicle runs on the electric motor alone, eliminating CO2 and NOx exhaust emissions. In normal driving conditions, power allocation is constantly adjusted between engine and electric motor to combine optimum performance with maximum fuel efficiency.
The Lexus Hybrid Drive system monitors itself at all speeds for optimum performance and fuel efficiency with minimum emissions, either running the electric motors in isolation, the engine in isolation, or a combination of both. Furthermore, the battery power level is constantly managed via the engine-driven generator, so there is no need for it to be recharged using an external source.