Japan: Mazda SkyActiv-G 1.3 Litre Engine does 70 MPG image

Mazda Motor Corp. (7261) has developed an engine 11% more fuel-efficient than existing models, the automaker announced Wednesday.

Japanese automaker said the first production application of its new Skyactiv-G 1.3-liter direct-injection gasoline engine will be in the face-lifted Mazda Demio, due shortly in Japan. Mazda said the Skyactiv-G 1.3 returns just over 70 mpg on Japan’s 10-15-mode test cycle.
It will be the first ever 1.3-liter direct-injection gasoline engine to be equipped in a compact car manufactured in Japan.

The breakthrough block features a record high compression ratio (for a regular gasoline mass production automobile engine) of 14.0:1 and exhibits high efficiency, especially under high load at low rpm. In order to avoid knocking – an unavoidable issue with conventional high-compression engines – the unit features a number of new technologies, such as piston cavities that are specially designed to support ideal combustion, and multi-hole injectors that enable precise fuel injection control.

Main features of the SKYACTIV-G 1.3 engine

– Highly efficient automobile gasoline engine and the world’s first to achieve a compression ratio of 14.0:1
– Multi-hole injectors enable precise fuel injection control for ideal combustion
– Mazda’s first dual sequential valve timing system (dual S-VT with electronically-operated intake) in combination with the high compression ratio achieves an unconventional Miller cycle (extremely delayed closure of intake valves) that improves efficiency
– Compact combustion chambers have a longer stroke for better efficiency
– Piston cavities are specially designed to support ideal combustion
– 30 percent less mechanical friction, due to a narrower crankshaft, new roller followers and low-tension piston rings that also reduce oil consumption
– Various countermeasures to prevent knocking, including a cooled EGR system
– An updated version of Mazda’s innovative idling stop system, i-stop, improves fuel economy by eight percent. It operates with a higher frequency, requires less fuel to restart, and achieves a smoother restart
– A lightweight and highly rigid aluminum alloy engine block

Major specifications of the SKYACTIV-G 1.3

– Inline four-cylinder 1.3-liter direct-injection engine (with i-stop)
– Engine displacement: 1.298/L
– Bore and stroke: 71.0mm x 82.0mm
– Compression ratio: 14.0:1
– Maximum output (net): 62k/w @ 5,400rpm (84ps @ 5,400rpm)
– Maximum torque (net): 112Nm @ 4,000rpm

* EGR: Exhaust Gas Recirculation