Toyota is ready to debut its second turbocharged entry in a series of new engines that boasts improved thermal and fuel efficiency.
The new 8NR-FTS 1.2-liter direct-injection turbo engine will be available as an option for the partially redesigned Auris, which recently went on sale in Japan. Like the other entries in Toyota’s new engine lineup, development of the 8NR-FTS is a culmination of Toyota’s experience in hybrid and conventional powertrain development, including advances in combustion and loss-reduction technologies. As a result, the OEM claims the new engine delivers superb driving performance and acceleration, while also achieving impressive fuel efficiency and thermal efficiency.
The engine pairs a single-scroll turbocharger with a cylinder head that uses an integrated water-cooled exhaust manifold to optimize exhaust temperature. This enables adaptive intake cooling that is not affected by the engine’s thermal load. The result is responsive acceleration and maximum torque across a wide rpm range.
Toyota has also improved combustion speed by creating a strong tumble flow inside the cylinder. This, together with D-4T (Direct-injection 4-stroke gasoline engine with turbo) technology, creates an ideal air-fuel mixture. In addition, continuous variable valve timing on the intake (VVT-iW) allows the engine to use the Atkinson cycle by adjusting valve timing according to load. These improvements combine to produce maximum thermal efficiency of 36%, according to in-house measurements, making the new engine a leader among mass-produced gasoline engines.
Despite the success of hybrids, Toyota is aware that vehicles with conventional powertrains still represent the majority of vehicles sold. By constantly increasing environmental performance across its entire vehicle lineup, Toyota aims to offer a portfolio of environment-friendly vehicles that meet the diverse needs of consumers.
April 8, 2015
