Student Book-HEV IC Engine Service

Language: English
File Type: PDF
Page: 13

Learning Objectives
Upon completion of Lesson Two, you should be able to:
§ Define the differences in a hybrid vehicle internal
combustion engine.
§ Identify hybrid vehicle internal combustion engine service
precautions.
The Prius Toyota uses a 1.5 liter inline 4-cylinder engine
(Figure 2-26) with VVT-i (Variable Valve Timing with
intelligence) and ETCS-i (Electric Throttle Control System with
intelligence). The engine includes a number of modifications that
help balance performance, fuel economy and clean emissions in
hybrid electric vehicles. One unique aspect of the 1NZ-FXE is its
Atkinson cycle valve timing, which allows the engine to decrease
emissions by varying the relationship between the compression
stroke and the expansion stroke. Another feature incorporated on ’04
& later models is a special coolant heat storage system that recovers
hot coolant from the engine and stores it in an insulated tank where it
stays hot for up to three days. Later, an electric pump precirculates
the hot coolant through the engine to reduce HC emissions normally
associated with a cold start.