Toyota will launch a range of next-generation powertrains in new models arriving from 2017.
In the five years to the end of 2021 there will be 17 versions of nine different new engines, 10 versions of four transmissions and 10 versions of six hybrid systems.
The Japanese brand has developed the engines and transmissions, and further evolved its hybrid technology, based on its Toyota New Global Architecture (TNGA) car structures.
TNGA, according to its creators, offers the means to change the makeup of cars right down to their basic structure, allowing bonnet heights to be reduced and centres of gravity to be lowered alongside other improvements.
Alongside these changes the new powertrains are being developed, promising significant improvements both in performance and environmental efficiency. The new engines are lighter and more compact, and with a lower centre of gravity to mirror the developments in vehicles platforms. A complete reassessment of what was needed has led to the creation of engines with high-speed combustion, matched to highly efficient multi-gear transmissions.
Toyota adds that the engines offering greater efficiency was a given but given equal importance in their development was that they should be fun to drive. The new engine/transmission combinations promise around 10 per cent more power but 20 per cent improved fuel economy.
The first release under what Toyota has named the ‘Dynamic Force Engines’ range is a direct-injection four-cylinder unit of 2.5 litres. Due for release in 2017 it is said to have one of the highest thermal efficiency levels – 40 per cent when used in a petrol-powered vehicle, 41 per cent in a petrol hybrid vehicle, and includes many new technologies.
Also announced are two new automatic transmissions, with either eight or 10 speeds. Both are light and compact, and include measures taken to minimise energy losses and increase efficiency.
The gear teeth have been treated with a new technique to achieve a lower friction coefficient when the gears engage, and the clutch friction material more precisely set to reduce clutch torque loss during rotation by approximately half over a conventional six-speed transmission.
Meanwhile the advances have also been applied to Toyota’s hybrid system – the existing THS 11 version combined with 2.5-litre petrol engines has been improved while a new high-performance Multistage THS 11 variant has been developed for rear-wheel-drive vehicles.
The hybrid developments are combined with the new lighter, more compact TNGA engine to offer major gains in power and fuel economy, while the Multistage version promises greater acceleration and more driving feel in performance cars.
Plug-in hybrid cars, meanwhile, will make use of a new dual-mode system that will allow the electric motor to directly power the car – previously it has only been used as a power generator. New lithium-ion batteries have been developed increasing the driving range in electric-only mode to 37 miles-plus.
The new powertrains are expected to be fitted to at least 60 per cent of the Toyota and Lexus model range by the end of 2021, in fuel efficiency alone cutting the C02 emissions of these models by at least 15 per cent.