SkyActiv

SKYACTIV is a brand name for a series of technologies developed by Mazda which increase fuel efficiency and engine output. The initial announcement of the SKYACTIV technologies include new engines, transmissions, body, and chassis, which appeared in Mazda products from 2011.^[1][2][3]

The Mazda SKY concept

The precursor of SKYACTIV, which featured a Mazda SKY-G 2.3-liter direct injection gasoline engine, a Mazda SKY-D 2.2-liter diesel engine, a SKY-Drive automatic transmission, a Mazda Kiyora with SKY-G 1.3 engine and SKY-Drive automatic transmission, was unveiled at the 40th Tokyo Motor Show in 2008.^[4][5]

SKYACTIV-G

SKYACTIV-G
Overview
Manufacturer	Mazda
Also called	SKY-G SKYACTIV-P
Production	2012-present
Combustion chamber
Configuration	Straight-4
Displacement	1,298 cc (79.2 cu in) 1,496 cc (91.3 cu in) 1,998 cc (121.9 cu in) 2,488 cc (151.8 cu in)
Cylinder bore	71.0 mm (2.80 in) 74.5 mm (2.93 in) 83.5 mm (3.29 in) 89.0 mm (3.50 in)
Piston stroke	82.0 mm (3.23 in) 85.8 mm (3.38 in) 91.2 mm (3.59 in) 100.0 mm (3.94 in)
Cylinder block alloy	Aluminum
Cylinder head alloy	Aluminum
Valvetrain	DOHC
Compression ratio	13.0:1 14.0:1
Combustion
Fuel system	Gasoline direct injection
Fuel type	Gasoline
Oil system	Wet sump
Cooling system	Water-cooled
Chronology
Predecessor	Mazda Z engine Mazda L engine

The SKYACTIV-G or formerly SKY-G^[6] is a family of direct injection gasoline engines. The engine compression ratio is increased to 14:1. To reduce the risk of engine knock at high compression, residual gas is reduced by using 4-2-1 engine exhaust systems, implementing a piston cavity, and optimizing fuel injection. In addition, combustion duration is shortened by intensifying air flow, increasing injection pressure, and using multi-hole injectors.

It features an all-aluminum construction with chain-driven dual overhead camshafts with VVT and gasoline direct injection; with direct ignition, it meets ULEV emission standards. SKYACTIV-G engines for the U.S. market have a lower compression ratio of 13:1 allowing them to operate on standard instead of premium fuel with an approximate 3-5 percent reduction in torque and fuel economy.^[7]

Generation 1

1.3 L

The SKYACTIV-G 1.3 is a variant with 1,298 cc (79 cu in) engine displacement and features a 71.0 mm (2.80 in) bore and a 82.0 mm (3.23 in) stroke.

The engine was unveiled at the 2011 Automotive Engineering Exposition.^[8][9]

Five Mazda engineers were awarded the 2011 Japan Society of Mechanical Engineers Medal on April 20, 2012 specifically for the "[d]evelopment of [a] gasoline engine (1.3L) with a super-high compression ratio and achieving fuel efficiency of 30km per liter (under Japan's 10-15 cycle)".^[10]

The engine was first used in the Mazda2 13-SKYACTIV.^[11][12]

It is rated at 83 hp (62 kW) and 83 lb·ft (113 N·m).^[13]

Applications:

• 2011–present Mazda2

1.5 L

The SKYACTIV-G 1.5 is a 1,496 cc (91.3 cu in) engine with a 74.5 mm (2.93 in) bore and a 85.8 mm (3.38 in) stroke.

This 4 cylinder engine was introduced in the 14MY Mazda3 for the Asian and European markets, it develops 99 hp (74 kW) at 6,000 rpm and 111 lb·ft (150 N·m) of torque at 4,000 rpm (Asia Markets). This new gasoline engine added to the SKYACTIV line-up achieves a high compression ratio of 13.0:1 (14.0:1 in some markets). It greatly improves dynamic performance and fuel economy over the MZR 1.5 engine of the previous model. Maximum power for the European model hatchback with automatic transmission is 115 hp (86 kW).

Applications:

• 2014–present Mazda3
• 2014–present Mazda2
• 2016–present Mazda MX-5

2.0 L

The SKYACTIV-G 2.0 or (P5-VPS) was the first engine in the SKYACTIV-G family to be produced.

This engine features a 1,998 cc (121.9 cu in) engine displacement, with a 83.5 mm (3.29 in) bore and a 91.2 mm (3.59 in) stroke. The U.S. version with a 13.0:1 compression ratio produces 155 hp (116 kW) at 6000 rpm and 150 lb·ft (200 N·m) of torque at 4000 rpm. In some markets, the 162 hp (120kW) and 210Nm torque is available.

According to Mazda, it is more fuel efficient than the engine it replaces. Versus the engine in the 2011 Mazda3 (with an automatic transmission), they improved fuel economy from 10.2 l/100 km (23 mpg_-US) to 8.4 l/100 km (28 mpg_-US) in town, and from 7.1 l/100 km (33 mpg_-US) to 5.8 l/100 km (41 mpg_-US) on the highway compared to the 2011 model.^[14]

Applications:

• 2012–present Mazda3
• 2013–present Mazda6
• 2013–present Mazda CX-5
• 2016–present Mazda MX-5

2.5 L

The SKYACTIV-G 2.5 or (PY-VPS) is a 2,488 cc (151.8 cu in) engine first used in the 2013 Mazda 6 and features a 89.0 mm (3.50 in) bore and a 100.0 mm (3.94 in) stroke.

The U.S. version with a 13.0:1 compression ratio produces 184 hp (137 kW) at 5,700 rpm and 185 lb·ft (251 N·m) of torque at 3,250 rpm.^[15]

Applications:

• 2014–present Mazda3
• 2013–present Mazda6
• 2013–present Mazda CX-5

Generation 2

Mazda's SkyActiv-G Generation 2 uses HCCI (homogeneous charge compression ignition) to reach a compression ratio of 18:1.^[16]

SKYACTIV-D

SH-VPTS SkyActiv-D Diesel engine

SkyActiv-D (SH-VPTR) Diesel engine(For Mazda 6)

SKYACTIV-D is a family of turbocharged diesel engines, designed to comply with global emissions regulations.

To eliminate the need of NOx and particulate treatment in contemporary diesel engines, the cylinder compression ratio is reduced to 14.0:1. Cold engine start is achieved via multi-hole piezo injectors with 3 programmable injection patterns, and adoption of ceramic glow plugs. Engine misfiring is prevented via variable valve lift at exhaust, which opens exhaust valves during the intake stroke, which increases engine air temperature. The SKYACTIV-D also uses a two-stage turbocharger, in which one small and one large turbo are selectively operated, according to driving conditions.

SKYACTIV-D 2.2

The SKYACTIV-D 2.2 (SH-VPTS) engine is the first SKYACTIV-D engine used in production vehicles. It was first used in the Mazda CX-5.^[17][18] In the Mazda6, it produces 129 kW (173 hp) and 420 N·m (310 lb·ft).^[19] An upgraded version of the SKYACTIV-D was run in the 2013 Rolex Sports Car Series season and helped Mazda win the GX manufacturer's championship. The engine is slated to be used again in two Lola LMP2s in the United SportsCar Series.

CX-5 with SKYACTIV-D engines were reported to have oil levels rising earlier than expected, which requires owners to check the vehicle's engine oil every 1000 kilometres or every month, but vehicles were reported to be returned to dealerships every 2000 km to prevent potential engine damage.^[20] Following the oil level problem, the launch of Mazda6 with SKYACTIV-D engines were delayed.^[21]

SKYACTIV-Drive

The SKYACTIV-Drive is a family of automatic transmissions, named SKY-Drive. Mazda rejected dual-clutch technology in automatic transmissions, because the dual-clutch behavior in certain situations was sub-optimal.^[22] Instead, Mazda chose to re-design the conventional automatic transmission, making the torque converter take less duty while a multi-plate clutch disengages the torque converter most of the time. The new SkyActiv automatic transmission was designed to have six gears forward, one reverse gear, a short torque converter and a clutch integrated with the torque converter.^[23]

SKYACTIV-MT

The SKYACTIV-MT is a family of manual transmissions.

To achieve lighter shift effort with a short shift lever stroke, the lever ratio is increased. However, to overcome the shorter internal stroke, a small module spline is used. Shift throws are reduced by 15 percent, making it the shortest shifting of any passenger car.

To allow weight reduction, the triple-shafted gear train is made with reverse and 1st gears on the same shaft, and the use of a shorter secondary shaft.

SKYACTIV-Body

The SKYACTIV-Body is a next-generation, lightweight, highly-rigid car body, with improved crash safety performance.

SKYACTIV-Hybrid

The SKYACTIV-Hybrid technology is an electric hybrid engine technology using SKYACTIV-G engine with hybrid technology from the Toyota Prius, originally licensed for use with SKY engine for vehicles sold in 2013.^[24][25]

The first retail Mazda SKYACTIV-Hybrid vehicle, a Mazda3 SKYACTIV-Hybrid with SKYACTIV-G 2.0 engine with 14:1 compression, was unveiled in 2013 Tokyo Motor Show.^[26][27]

SKYACTIV-CNG

The SKYACTIV-CNG engine is powered by compressed natural gas.

The first retail Mazda SKYACTIV-CNG prototype vehicle, a Mazda3 SKYACTIV-CNG Concept, was unveiled in 2013 Tokyo Motor Show.^{[28][29][30][31]}

References

External links

• Mazda SKYACTIV TECHNOLOGY page
• Mazda Canada SKYACTIV TECHNOLOGY page