Engine and Drivetrain
Under the hood is a 1.8-litre VVT-i Atkinson cycle 2ZR-FXE engine, the same engine code as the previous generation Prius. It is however, a very different engine.
Despite sharing the same engine block and valvetrain (therefore retaining the same model code), this new engine uses large-volume exhaust gas recirculation (EGR) system, has a redesigned air intake port improves airflow inside the combustion chamber, while the coolant passages have been redesigned to optimize internal engine temperature. The friction created by the piston skirts, rotating parts and the oil pump has been reduced, while the use of low-viscosity oil reduces friction between sliding engine components. All this add up to deliver a thermal efficiency of 40 percent (1.5 percent higher than before) – the world’s highest for a petrol engine.
All key hybrid components ―including the motors, transaxle, power control unit and hybrid batteries―are now smaller and lighter.
The MG1 and MG2 pair of motor-generators, a key component in the Prius’s two-motor full-hybrid system, are all-new and uses an innovative rolling-coil structure.
Further aiding fuel economy is an automatic grille shutter that opens and closes the grille as necessary in response to outside temperatures.
Claimed fuel economy is 40 km/litre (up from 32.6 km/litre) when tested under the Japanese JC08 driving cycle. The all-new Prius has yet to be tested under the US EPA or European NEDC driving cycle it will only go on sale in these markets later next year.
The petrol engine is produces 97 hp at 5,200 rpm, and 142 Nm of torque at 3,600 rpm. This is further boosted by the 71 hp (53 kW) electric motor.
Choice of Li-On and NiMh Traction Battery
Depending on markets, the Prius can be specified with either a Li-On or NiMh traction battery, which has been moved from behind the rear seats to under it.
Relocating the batteries have freed up 56 litres of cargo volume, bringing it up to 502 litres.
E-Four AWD Option
Certain markets will have the option of an AWD Prius. Rather than a mechanical AWD drivetrain, the Prius uses another 53 kW motor (same as the ones driving the front axle) to drive the rear axle. To support the motor’s functions, an air-cooled inverter (the one fitted in front is liquid cooled) is also installed in the rear’s rear section.
Chassis And Body Control
The all-new Prius’s TNGA platform has accorded it with a significantly stiffer chassis (torsional rigidity up by 60 percent) and a better driving experience thanks to its lower centre of gravity.
Driver and passenger hip points in the Prius have been lowered by 59 mm, combining with optimized placement of the steering wheel and pedals.
The welds along the frame are now completed using Laser Screw Welding rather than conventional spot welds, while other sections are held together using structural body adhesives, and the use of ring-shaped frame structures. Toyota says these improvements combine to produce a firmer, more stable ride.
The regenerative braking system has been improved by using a new active hydraulic booster, which Toyota says emits less noise and improves pedal feel.
The rear axle is now suspended using an all-new double wishbone rear suspension (previous model uses torsion beam).
Is It Coming To Malaysia?
Unlikely. Without the tax incentives that the previous generation Prius enjoyed, the Prius will be priced way too high, like above RM250k. However, there is a chance that the car might be available on a special order basis, for those few that can stomach the price.
More on the all-new fourth generation Toyota Prius in the videos below.