Toyota Prius

A new hybrid system and platform enable the vehicle to compete with its combustion engine rivals

The platform allowed for a lower centre of gravity, by 25mm, to be realised. Toyoshima explains that handling response and stability have directly benefited from this, with body roll reduced.

“By lowering the centre of gravity we improved the driving performance,” he says.

The vehicle’s driving dynamics were further enhanced through the choice of materials. Greater use of high-strength steel across the vehicle and extra reinforcements to the centre pillar’s lower structure and panel connections have led to body rigidity rising by 60%.

A new double-wishbone suspension at the rear supports a smoother drive, with a 50% improvement in shock damping compared with the outgoing torsion-beam system.

It was something I noticed for myself when the vehicle made minimal work of the uneven roads in London I drove the Prius on recently.

Rubber bushings have replaced ball joints in key areas to reduce vibrations, and there are several bushings per side, compared to one on the old design.

Built-in flexibility

The rear suspension layout offers greater flexibility for fine-tuning the calibration too.

The MacPherson strut suspension at the front is retained but the hardware, geometry and calibration have all been revised. New shock absorbers reduce strut friction by 37%.

Toyoshima and his team also paid a great deal of attention to aerodynamic performance. He says: “The shape of the edge of the headlamp, for example, is not just for styling, and all the small efforts lead to better aerodynamics overall.

“To achieve that, we made a new wind tunnel. In the past we just had a static simulation where the floor did not move, but now it does and we can do actual driving simulations.”

The peak of the car’s roof was shifted forwards by 17cm for similar reasons and the Prius’s Cd figure is now 0.24, lower than the 0.25 of the previous model.

Toyota wants the hybrid vehicle to compete with combustion-only rivals and, all things considered, the new platform may allow it to do that better than in the past.

tags: June 2016 Toyota Hybrids & EVs