Although Toyota has heavily invested into its hybrid vehicle program, the company is still hard at work developing new internal combustion engines, as those still represent the vast majority of vehicle propulsion systems across the globe.
Their new 8NR-FTS engine is a 1.2-liter, direct-injection turbocharged marvel of engineering that takes into account the company’s development in both traditional internal combustion engines and some of the advances they’ve engineered into their hybrid powerplants as well. The engine will be available in the company’s Auris model, which went on sale in Japan on April 6th, 2015.
The 8NR-FTS is equipped with a single-scroll turbocharger combined with a cylinder head that uses an integrated water-cooled exhaust manifold to help control exhaust gas temperatures. This design allows the engine to use an adaptive intake cooling system that is not affected by the engine’s thermal load, which gives pinpoint acceleration response along with maximum torque across the rpm range.
Combustion performance is also improved within the cylinders through the creation of a vertically-rotating swirl (tumble flow) air path. The tumble flow, combined with direction injection turbocharging, allows the air/fuel mixture to remain optimum.
Perhaps the most notable achievement of this engine platform is its ability to use the Atkinson cycle by continuously adjusting the valve timing according to the load through the use of Toyota’s Variable Valve Timing-intelligent Wide (VVT-iW) system. Thermal efficiency for the engine platform hovers at 36 percent, which is the upper echelon of mass-produced gasoline engines, according to the company.