The New Toyota Inline 4 Cylinder 1.2L ESTEC D-4T Engine

Authors

K. Hikichi, I. Watanabe, T. Shinagawa, M. Kudo, Toyota Motor Corporation, Toyota, Japan

Year

2015

Print Info

Fortschritt-Berichte VDI, Reihe 12, Nr. 783

Summary

Toyota Motor Corporation is developing a series of engines belonging to its ESTEC (Economy with Superior Thermal Efficient Combustion) development concept. Subsequent to the launch of the 2.0-liter DI Turbocharged 8AR-FTS, this paper describes the development of the 8NR-FTS, a 1.2-liter inline 4-cylinder spark ignition downsized turbocharged direct injection (DI) gasoline engine. Following the same basic concepts as the 8AR-FTS engine [1], the 8NR-FTS incorporates various fuel efficient technologies such as a cylinder head with an integrated exhaust manifold, the Atkinson cycle using a centre-spooled variable valve timing with mid-position lock system (VVT-iW), and intensified in-cylinder turbulence to achieve high-speed combustion. Instead of the D-4ST system that incorporates port and direct injection, the 8NR-FTS emphasizes compactness by adopting the D-4T system that performs only DI in each cylinder. In combination with a single-scroll turbocharger, high torque is achieved from low engine speeds by cooperative control with the VVT system. This engine also adopts a stop and start control strategy that achieves speedy and shock-free re-start performance by starting the engine with stratified injection in the first compressed cylinder. The engine can be mated with either a 6-speed manual transmission (6MT) or continuously variable transmission (CVT).