|1.3L SKYACTIV-G. Click to enlarge.|
The first of Mazda Motor Corporation’s next-generation SKYACTIV technologies (earlier post) to be introduced to the market will be the SKYACTIV-G 1.3 direct-injection 1.3-liter gasoline engine. Mazda will unveil the engine at the Automotive Engineering Exposition that will be held from 18 – 20 May at the Pacifico Yokohama convention center near Tokyo, Japan.
The SKYACTIV-G 1.3 features a 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, the SKYACTIV-G 1.3 features a number of new technologies, such as piston cavities that are specially designed to support optimized combustion, and multi-hole injectors that enable precise fuel injection control.
|SKYACTIV-G 1.3 (w i-stop)|
|Bore and stroke||71.0mm x 82.0mm|
|Maximum output (net)||62 kW|
|Maximum torque (net)||112 N·m @4,000rpm|
Mazda plans to introduce the SKYACTIV-G 1.3 to the Japanese market in the facelifted Mazda Demio (known overseas as the Mazda2) during the first half of 2011. It will be the first 1.3-liter direct-injection gasoline engine to be equipped in a compact car manufactured in Japan. Combined with an updated version of Mazda’s idling stop system, i-stop, and a continuously variable transmission (CVT), SKYACTIV-G 1.3 will achieve fuel economy of 30 km/L (71 mpg US, 3.33 L/100km) under Japan’s 10-15 mode test cycle.
Mazda’s i-stop is an intelligent proprietary engine stop-start system. The system precisely controls the positions of the pistons during engine shutdown, and then uses Mazda’s direct injection technology to perform a combustion restart. The updated version operates with a higher frequency, requires less fuel to restart, and achieves a smoother restart.
Mazda has applied for more than 130 patents in relation to the engine as of the end of February, 2011.
SKYACTIV is the umbrella term for Mazda’s range of next-generation technologies—including gasoline and diesel engines, transmissions, and a new body and chassis—that significantly improve vehicle driving dynamics as well as environmental and safety performance. The SKYACTIV-G 1.3 that is equipped in the facelifted Mazda Demio adopts all of Mazda’s SKYACTIV engine technologies except for the exhaust manifold. It also features other new components that are exclusive to the Demio, such as a cooled EGR system.
The engine also features Mazda’s first dual sequential valve timing system (dual S-VT with electronically-operated intake) which, in combination with the high compression ratio, achieves an unconventional Miller cycle (extremely delayed closure of intake valves) that improves efficiency.
Other features of the engines include:
- Compact combustion chambers have a longer stroke for better efficiency;
- Piston cavities are specially designed to support ideal combustion;
- 30% 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; and
- A lightweight and highly rigid aluminum alloy engine block.