Toyota promises better mileage and ride with Prius hybrid

The achievements marked by the first three generations provide an impressive platform on which the all-new fourth generation Prius is set to achieve even greater advances, including the unprecedented target of an 18 per cent improvement in efficiency1.

Prius engineers said Tuesday they set out to match the performance of diesel engines, a choice of powertrain favored by Volkswagen until its recent scandal. However, the engine has been completely re-engineered, with remarkable results in terms of performance, fuel economy, and reductions to size and weight. The 1.8-liter four has been redone and now has 40 percent better thermal efficiency. Additionally, the coolant passages have been redesigned to optimize the engine’s internal temperature. In addition, friction between sliding engine components has been reduced.

Today the Japanese automaker announced details on the extensive improvements we’ll see on the 2016 Toyota Prius, including its confirmed 10 percent higher fuel-efficiency. With a more compact design, the unit can now be positioned directly above the transaxle. Both motors feature an innovative rolling-coil structure. The people at Toyota have redesigned the transaxle and the electric motor which punches out 73bhp to to lower mechanical losses through friction by approximately 20% thanks to a new multi-axle design. This is helped by the relocation of the auxiliary batteries from the boot to the engine compartment while the new hybrid battery is now beneath the rear seats. Being smaller (again, it didn’t say how much), they’re now relocated under the rear seat, increasing cargo space.

The Prius is available with either a new lithium-ion or nickel-metal hydride hybrid battery.

The bump in fuel efficiency will mean that the Prius will now be able to return an economy figure of 40 km/l and that is a massive jump. The motor is more compact giving it an improved power-to-weight ratio.

Toyota has managed to achieve this because it has implemented a dual cooling system that automatically reduces the volume of coolant flow in the engine to achieve a quicker warm-up. New updates to the hybrid system software improve the feel of acceleration, giving a smooth and direct response in a lower rpm range. A new double-wishbone rear suspension and lower center of gravity (in part a product of the new battery positioning) should help. Through TNGA, body torsional rigidity has been improved by more than 60 percent compared with previous models, due to the use of Laser Screw Welding (which allows for welds at shorter intervals along the frame compared with spot welding), structural body adhesives, and the use of ring-shaped frame structures. Together these contribute to achieving a more stable ride. The pack is located under the rear seats in both models, a packaging solution that gives the new Prius a much more spacious trunk than the model it is replacing.