Toyota introduces turbocharged gasoline engine with 36% thermal efficiency

7 April 2015

Toyota introduced a new turbocharged gasoline engine with “drastically 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 model, which went on sale in Japan. This is a second turbocharged entry in a series of new Toyota engines, following the 2.0-liter engine in the Lexus NX 200t introduced last year.

The engine combines 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, which results in responsive acceleration and maximum torque across a wide rpm range, said Toyota.

Toyota 8NR-FTS 1.2 L gasoline direct injection turbo engine

Combustion speed has been improved by creating a strong tumble flow (a vertically-rotating swirl) inside the cylinder. In addition, continuous variable valve timing on the intake (VVT-iW, Variable Valve Timing-intelligent Wide) allows the engine to use the Atkinson cycle, in which thermal efficiency is improved by making the expansion ratio larger than the compression ratio. These improvements produce a maximum thermal efficiency of 36%, a leading level among mass-produced gasoline engines, noted Toyota.

The main specifications of the 8NR-FTS engine are:

Displacement: 1,196 cc
Bore and stroke: 71.5 × 74.5 mm
Compression ratio: 10.0
Maximum output: 85 kW (116 hp) / 5,200-5,600 rpm
Maximum torque: 185 Nm (18.9 kGm) / 1,500-4,000 rpm

Source: Toyota