The powertrain is an updated version of the existing combination of a 1.8-litre petrol engine and an electric motor, featuring a more compact nickel-metal hydride battery pack that's quicker to charge. The combustion engine produces of 97bhp and 105lb ft, while the electric motor brings 71bhp. Toyota also says it has revised the Prius's regenerative braking system, introducing a new active hydraulic booster that's designed to be quieter and give a more natural feel to the brake pedal.
Toyota hasn’t issued any definitive CO2 emissions or fuel economy figures - it says EU NEDC numbers will be released at a later date - but it has revealed that this Prius will bring efficiency gains of 18% over its predecessor. That's the biggest jump between generations in Prius history, and could give the car CO2 emissions and combined fuel economy of 73g/km and 85mpg.
The new Prius is 4540mm long - an increase of 60mm over the outgoing model - and has the same wheelbase of 2700mm. The more compact powertrain has allowed the auxiliary batteries to be moved to the engine bay and the hybrid batteries to be relocated to below the rear seats. These measures and the slightly longer rear overhang give the new Prius improved boot capacity, up from 445 litres to 502 litres.
The construction of the fourth generation of the Prius marks a significant step for Toyota. It is the first model to be developed on the firm’s Toyota New Global Architecture (TNGA) platform, a modular set of components designed to offer quicker development of new models as well as cost savings and improved margins across the product line-up.
The new platform brings a more sophisticated chassis than that of the outgoing Prius. Double wishbone rear suspension replaces the current torsion beam layout, accompanying a revised MacPherson set-up at the front. Toyota says the new platform helps to lower the centre of gravity and that this will give the Prius “improved handling response and agility”. It also brings gains in rigidity; the new Prius brings an increase of more than 60% in body rigidity, Toyota claims.
The TNGA will play a key part in Toyota’s future product plans. The firm has previously stated that up to 50% of its global product line-up will eventually switch to the new architecture and that it will offer gains in body rigidity of between 30% and 65%.
The front of the Prius gets more dramatic headlights and complex surfacing on the bumper, while the side profile is helped by a blacked-out C-pillar that’s designed to create a ‘floating roof’. The rear has clear cues from the Mirai, including the deep crease above the back wheels, tall tail-lights and a spoiler integrated into the hatchback glass.
The cabin gets a dual 4.2-inch digital instrument panel, a colour head-up display and a redesigned air-conditioning system that knows which seats are occupied and adjusts its airflow accordingly for maximum efficiency.
Comment - Why the new Prius matters
Toyota may make great claims about the high percentage of Auris hybrids in the overall sales mix and the enthusiastic response to the Mirai fuel cell vehicle, but the Prius is likely to remain the flag-bearer for the company’s hybrid powertrains for some time to come.
So successful has the model been that for many people, Prius is hybrid.
Don’t expect a revolution in the powertrain technology that underpins the new car — although even modest gains should be enough for the Prius to trump the NEDC efficiency test and get under the magic 80g/km CO2 mark.