Jump to content

Skyactiv

From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by Areaseven (talk | contribs) at 13:26, 29 January 2021 (Skyactiv-X). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Skyactiv
Overview
ManufacturerMazda

Skyactiv (branded as SKYACTIV) is a brand name for a series of technologies developed by Mazda that increase fuel efficiency and engine output. The initial announcement of the Skyactiv technologies included 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 gas 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] The Skyactiv concept features a revised suspension geometry, improved automatic and manual transmission, and various improvements to Mazda's L- engine such as direct injection, upgraded exhaust manifold, increased compression ratio for cleaner burn and higher thermal efficiency, etc. Mazda's previous chassis for the Mazda 3 and Mazda 6 were carried over to the new vehicles.

Skyactiv-G

Skyactiv-G
Overview
Also called
  • Sky-G
  • Skyactiv-P
Production2012-present
Layout
ConfigurationInline-four
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 materialAluminum
Cylinder head materialAluminum
ValvetrainDOHC
Compression ratio
  • 13.0:1
  • 14.0:1
  • 10.5:1 (Turbo)
Combustion
Fuel systemPetrol direct injection
Fuel typePetrol / Petrol Flexifuel (Some Version)
Oil systemWet sump
Cooling systemWater-cooled
Chronology
Predecessor

The Skyactiv-G or formerly Sky-G[6] is a family of direct injection petrol engines. The engine compression ratio is increased to 14.0:1 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]

1.3 l

The Skyactiv-G 1.3 (P3-VPS) is a variant with 1,298 cc (79.2 cu in) engine displacement and features a 71.0 mm (2.80 in) bore and an 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 "development of a petrol engine (1.3 L) with a super-high compression ratio and achieving fuel efficiency of 30 km per litre (under Japan's 10-15 cycle)".[10] The engine was first used in the Mazda2 1.3-Skyactiv.[11][12]

It is rated at 62 kW and 113 N·m.[13]

Applications:

1.5 l

The Skyactiv-G 1.5, or (PR-VP RS) for RWD applications and (P5 VPS F-P5) for FWD applications, is a 1,496 cc (91.3 cu in) engine with a 74.5 mm (2.93 in) bore and an 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 85 kW (114 hp) at 6,000 rpm and 111 lb⋅ft (150 N⋅m) of torque at 4,000 rpm (Asia Markets). This new petrol 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.

Applications:

2.0 l

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

This engine features an engine displacement of 1,998 cc (2.0 L; 121.9 cu in), with a bore X stroke of 83.5 mm × 91.2 mm (3.29 in × 3.59 in). The U.S. version has a compression ratio of 13.0:1 producing 155 bhp (157 PS; 116 kW) at 6000 rpm and 200 N⋅m (148 lbf⋅ft) of torque at 4600 rpm.[14] In some markets, the 162 bhp (164 PS; 121 kW) and 210 N⋅m (155 lbf⋅ft) of torque with Flexifuel E85 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.[15]

The MX-5 ND2 2019 facelift received an updated engine producing 181 bhp (184 PS; 135 kW) with maximum RPM raised from 6800 to 7500 rpm and includes a larger intake manifold, increased injection pressure and a new exhaust system that scavenges the cylinders quicker.[16]

Applications:

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 an 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 187 hp (139 kW) at 6,000 rpm and 252 N⋅m (186 lb⋅ft) of torque at 4,000 rpm.[17]

Skyactiv-G 2.5 engines manufactured from 2018 onwards feature cylinder deactivation to improve fuel efficiency.[18] In July 2019, approximately 262,000 Mazda vehicles using the engine were recalled for a faulty powertrain control module that may cause a misfire or a loss in power.[19]

The turbocharged version or (PY-VPTS) operates with a 10.5:1 compression ratio,[20] and produces 250 hp (190 kW) and 430 N⋅m (320 lb⋅ft).

Applications:

Skyactiv-X

Skyactiv-X
Overview
Also called
  • Sky-X
Production2019-present
Layout
ConfigurationInline-four
Displacement1,998 cc (121.9 cu in)
Cylinder block materialAluminum
Cylinder head materialAluminum
ValvetrainDOHC
Compression ratio16.3:1
Combustion
Fuel systemPetrol direct injection
Fuel typePetrol
Oil systemWet sump
Cooling systemWater-cooled

Skyactiv-X is the first commercial petrol engine to use homogeneous charge compression ignition (HCCI), in which the fuel-air mixture ignites spontaneously when compressed by the piston. This allows it to reach a compression ratio of 16:1 instead of 14.0:1 of previous generation and operate much leaner than a spark ignition engine, reducing fuel consumption and emissions.[21][22]

This engine targets 20-30% greater fuel efficiency by utilising HCCI technology. In order to handle ignition problems caused by compression ignition, each cylinder also incorporates a spark plug featuring Spark Controlled Compression Ignition (SPCCI) technology.[23] A small Roots-type supercharger further expands the compression ignition operating window by feeding more air into the engine, leaning out the mixture sufficiently for compression ignition even at higher speeds. [24]

SPCCI works by drawing in a lean, homogenous air-fuel mixture, it then compresses the mixture until it approaches the point at which it would spontaneously detonate. A second injector then adds a secondary charge of fuel directly on the spark plug. This secondary charge is ignited by the spark plug, causing the cylinder pressure to very quickly rise to a point where the rest of the fuel undergoes compression ignition. The presence of the spark plug allows the engine to also operate as a spark-ignition engine under some operating conditions, such as high-speed high-load situations. Revealed June 5, 2019, the output is 132 kW (177 hp) and 224 N⋅m (165 lbf⋅ft).[23]

Applications:

Skyactiv-D

Skyactiv-D
Overview
Also calledSky-D
Production2014-present
Layout
ConfigurationInline-four
Combustion
Fuel systemCommon rail
Fuel typeDiesel
Oil systemWet sump
Cooling systemWater-cooled
Chronology
PredecessorMazda R 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.

S5-DPTS/S5-DPTR

Also known for Skyactiv-D 1.5 (1,499 cc (91.5 cu in)) engine was first introduced in the fourth generation Mazda Demio/Mazda2. It features a compression ratio of 14:1.[25]

Applications:

S8-DPTS/S8-DPTR

Also known for Skyactiv-D 1.8 (1,759 cc (107.3 cu in)) was introduced in the 2018 facelifted Mazda CX-3.[26]

Applications:

SH-VPTS/SH-VPTR

Also known for Skyactiv-D 2.2 (2,191 cc (133.7 cu in)) engine is the first Skyactiv-D engine used in production vehicles. It was first used in the Mazda CX-5.[27][28] In the Mazda6, it produces 129 kW (173 hp) and 420 N⋅m (310 lb⋅ft).[29] 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.

Unique technology

The Skyactiv-D is the first low compression diesel in a production car, having a significantly lower compression in the first generation of 14:1 rather than higher compression ratios of 16:1 and higher.[30] Numerous university studies have investigated the benefits of low compression diesel for decades, with the major benefit noted in single cylinder university tests of being a drastic reduction in NOx emissions, while also reducing particulate matter and combustion noise.[31][32] These studies all concluded that while there were noticeable reductions in emissions, this came at the expense of difficult cold starts. Mazda resolved this in the Skyactitv-D by using piezoelectric fuel injectors with multiple nozzles that changes the pattern depending on operating conditions. Furthermore, exhaust valves are left slightly open as the engine starts causing exhaust gases to be sucked into the cylinders helping the engine to warm up quickly.[30]

Early issues

The CX-5 with Skyactiv-D engines were reported to have oil levels rising earlier than expected upon release, which required owners to check the vehicle's engine oil every 1000 kilometres or every month and return to the dealer if the oil appeared over the level of the dipstick.[33] This procedure was initiated by Mazda worldwide as a precaution. Mazda did however resolve the issue in the first few months of the engine being available, with the resolution being a software change and a change of dipsticks with a corrected level.[citation needed]

Emission standards and tests

At launch in 2012, Mazda claimed the Skyactiv-D engine would only comply with Euro 5 emission standards (NOx of 0.18 g/km), and further work was required to achieve stricter emission standards.[citation needed]

In the aftermath of the Volkswagen emissions scandal, the Japanese government performed testing of all diesel engines produced in Japan to ensure Japanese manufacturers were not falsifying emissions as had been done by Volkswagen. It was determined that the Skyactiv-D engine was the only engine which tested at or near the standard.[34]

Achieving US EPA emission standards

At the 2019 New York Motor show, Mazda announced that it would commence pre-sales of the 2019 CX-5 with the Skyactiv-D 2.2L engine.[35] To achieve the US EPA emissions standards though has resulted is significant performance and economy penalties in comparison with the Euro 5 compliant engine. The Australian version of the engine is a good comparison with that in the US, with both countries requiring identical diesel quality and using the higher specification of the engine.

The Euro stage V compliant Australian Skyactiv-D 2.2L has the following specifications:[36]

  • Power: 140 kW (190 hp) @ 4,500 rpm
  • Torque: 450 N⋅m (330 lbf⋅ft) @ 2,000 rpm
  • Fuel consumption (Australian ADR 81/02)
    • Combined 5.7 l/100 km (41.3 mpg)
    • City 6.5 l/100 km (36.2 mpg)
    • Highway 5.2 l/100 km (45.2 mpg)

The US EPA compliant US Skyactiv-D 2.2l has the following specifications:[37]

  • Power: 168 hp @ 4,000 rpm
  • Torque: 290 lb-ft @ 2,000 rpm
  • EPA Estimated fuel economy:
    • City 27 mpg
    • Highway 30 mpg

Recall

In September 2016, Mazda recalled 130,000 vehicles in Japan over a defect that could lead to diesel engine failure.[38]

Although most problems were fixed later on the 2.2 suffered from bad carbon build up that would block the intake manifold. Other faults include the turbo diversion valve failure that required replacement of the complete twin turbo unit.

Mazda recalled 2012 to 2018 diesel Mazda 3, Mazda 6 and CX-5 because of carbon deposits build-up.[39]

Skyactiv-Hybrid

The Skyactiv-Hybrid technology is an electric hybrid engine technology using Skyactiv-G engine with technology from Toyota's Hybrid Synergy Drive, originally licensed for use with the Sky engine for vehicles sold in 2013.[40][41]

The first retail Mazda Skyactiv-Hybrid vehicle, a Mazda3 Skyactiv-Hybrid with Skyactiv-G 2.0 engine with 14:1 compression, was unveiled at the 2013 Tokyo Motor Show.[42][43]

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.[42][43][44][45]

Skyactiv-R

The Skyactiv-R engine is Mazda's new generation rotary engine. However, the engine has never been shown to the public to prove its existence.

The Mazda RX-Vision Concept, powered by a Skyactiv-R rotary engine, was unveiled in 2015 Tokyo Motor Show.[46]

e-Skyactiv

e-Skyactiv is the battery electric powertrain.[47]

e-Skyactiv-G

e-Skyactiv-G is the first Mild Hybrid powertrain.

Applications:

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.[48] 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.[49]

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.[citation needed]

To allow weight reduction, the triple-shafted gear train is made with reverse and first 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. The Skyactiv-Body is 8% lighter and 30% more rigid than previous generations.[50][better source needed]

Applications:

References

  1. ^ "Mazda groups suite of new technologies under the "Skyactiv" umbrella". Autoblog.com. Retrieved 13 July 2018.
  2. ^ "【MAZDA】ニュース". Mazda.co.jp. Retrieved 13 July 2018.
  3. ^ "MAZDA: Mazda Reveals Next-Generation 'SKYACTIV' Technologies - News Releases". Mazda.com. Retrieved 13 July 2018.
  4. ^ "MAZDA: Mazda Global Premiere of Eco-Friendly and Powerful Next Generation 'SKY-G' and 'SKY-D' Engines at Tokyo Motor Show 2009 - News Releases". Mazda.com. Retrieved 13 July 2018.
  5. ^ "【MAZDA】ニュース". Mazda.co.jp. Retrieved 13 July 2018.
  6. ^ "Prototype Mazda3 with 2.0L Sky-G engine gets 30/40 mpg". Autoblog.com. Retrieved 13 July 2018.
  7. ^ "Mazda Skyactiv-G and Skyactiv-D Engines in Detail". Caranddriver.com. Retrieved 13 July 2018.
  8. ^ "MAZDA: Mazda Develops Highly Efficient "SKYACTIV-G 1.3" Direct-Injection Gasoline Engine - News Releases". Mazda.com. Retrieved 13 July 2018.
  9. ^ "【MAZDA】ニュース". Mazda.co.jp. Retrieved 13 July 2018.
  10. ^ "Skyactiv Tech Wins 2011 Japan Society of Mechanical Engineers Medal". Integrityexports.com. Retrieved 13 July 2018.
  11. ^ "MAZDA: Pre-Orders Start for Facelifted Mazda Demio in Japan - News Releases". Mazda. Retrieved 13 July 2018.
  12. ^ "【MAZDA】ニュース". Mazda. Retrieved 13 July 2018.
  13. ^ "Mazda 2 with New 1.3-liter SKYACTIV-G Engine Gets Claimed 50-Percent Mileage Boost". Blog.caranddriver.com. Retrieved 13 July 2018.
  14. ^ "Mazda MX-5 Miata RF Club, 2017 MY US". carfolio.com. February 22, 2017. Retrieved July 27, 2018.
  15. ^ "Turning Up the Pressure to Keep Gas in the Game". New York Times. November 11, 2011. Retrieved 2011-11-14. But the most daring advance is the 2-litre Skyactiv-G gasoline engine. That 4-cylinder power plant made its North American debut in the 2012 Mazda 3, where it raised the fuel economy rating to 8.5 l/100km in town and 5.8 on the highway with an automatic transmission, from 24/33 for the 2011 model sedan with a 2-litre engine. ...
  16. ^ "New Mazda MX-5 2018 facelift review". autoexpress.com. August 30, 2018. Retrieved February 12, 2019.
  17. ^ Orlando, Sport Mazda (12 December 2012). "MazdaExperts-SportMazdaOrlando.com: Mazda Debuts The New Skyactiv-G Petrol 2.5 Liter Engine". Mazdaexperts.blogspot.com. Retrieved 13 July 2018.
  18. ^ "Mazda's New Technology Makes Skyactiv-G Even Better". Mazda. Retrieved 2020-12-21.
  19. ^ Krok, Andrew (2019-07-11). "Mazda recalls 262,000 cars and SUVs for cylinder deactivation issues". CNET. Retrieved 2020-12-21.
  20. ^ "2020 Mazda CX-9 Digital Owner's Manual". mazdausa.com. Retrieved 28 October 2020.
  21. ^ "MAZDA: Mazda Announces Long-Term Vision for Technology Development, 'Sustainable Zoom-Zoom 2030' - News Releases". 2.mazda.com. Retrieved 13 July 2018.
  22. ^ "Next-Generation Skyactiv-X gasoline engine". Mazda Motor Corporation. Retrieved 2018-04-02.
  23. ^ a b Engineering Explained (2017-08-13), Mazda Creates The Holy Grail Of Gasoline Engines - HCCI SkyActiv-X, retrieved 2017-08-13
  24. ^ "Driving Mazda's Next Mazda 3 with Its Skyactiv-X Compression-Ignition Gas Engine". Car and Driver. Retrieved 29 January 2021.
  25. ^ "Next Mazda2 will Feature New SKYACTIV-D 1.5 Small-Displacement Clean Diesel Engine". Mazda. 2014-06-10. Retrieved 2018-11-12.
  26. ^ Beckwith, Jimi (2018-08-22). "Facelifted Mazda CX-3 arrives with first 1.8 Skyactiv-D engine". Autocar. Retrieved 2018-11-12.
  27. ^ "MAZDA: Mazda to Introduce Next-Generation Clean Diesel Vehicles in Japan - News Releases". Mazda.com. Retrieved 13 July 2018.
  28. ^ "【MAZDA】ニュース". Mazda.co.jp. Retrieved 13 July 2018.
  29. ^ "2014 Mazda 6 2.5L / 2.2L Diesel". Caranddriver.com. Retrieved 13 July 2018.
  30. ^ a b "Difference Engine: Born again". The Economist. 2013-07-08. ISSN 0013-0613. Retrieved 2019-05-02.
  31. ^ Pacaud, P.; Perrin, H.; Laget, O. (2009). "Cold Start on Diesel Engine: Is Low Compression Ratio Compatible with Cold Start Requirements?". SAE International Journal of Engines. 1 (1): 831–849. ISSN 1946-3936. JSTOR 26308324.
  32. ^ "A survey on low compression ratio diesel engine". ResearchGate. Retrieved 2019-05-02.
  33. ^ "Backlash over Mazda CX-5 diesel oil issues". News.drive.com. Archived from the original on 2014-03-06. Retrieved 13 July 2018.
  34. ^ Schmitt, Bertel. "Japan Releases (Nasty) Diesel Test Results, Germany Sits On Them". Forbes. Retrieved 2019-05-02.
  35. ^ "Mazda announces CX-5 diesel sales start in North America". www.mazda-press.com. Retrieved 2019-05-02.
  36. ^ "Mazda CX-5 | Specs & Prices". www.mazda.com.au. Retrieved 2019-05-02.
  37. ^ "Reserve 2019 MAZDA CX-5 SIGNATURE SKYACTIV®-D | Mazda USA". www.mazdacx-5diesel.com. Retrieved 2019-05-02.
  38. ^ Horie, Masatsugu (Sep 1, 2016). "Mazda Recalls Japan Diesel Models". Bloomberg. Retrieved 1 October 2016.
  39. ^ "Mazda 3, 6, CX-5 recalled | CarAdvice". CarAdvice.com. Retrieved 10 June 2020.
  40. ^ "トヨタとマツダ、ハイブリッドシステムの技術ライセンス供与に合意" (PDF). Mazda.com. Retrieved 13 July 2018.
  41. ^ "TMC and Mazda Agree to Hybrid System Technology License" (PDF). Mazda.com. Retrieved 13 July 2018.
  42. ^ a b "Mazda3 Skyactiv-Hybrid and CNG Concept shown in Japan". Retrieved 13 July 2018.
  43. ^ a b "Mazda3 to showcase CNG, Hybrid versions in Tokyo". Autoblog.com. Retrieved 13 July 2018.
  44. ^ "【MAZDA】マツダ、東京モーターショーに新型「アクセラ」を出品|ニュースリリース". Mazda.com. Retrieved 13 July 2018.
  45. ^ "MAZDA: Mazda to Exhibit All-New Mazda3 at Tokyo Motor Show - News Releases". Mazda.com. Retrieved 13 July 2018.
  46. ^ "MAZDA NEWSROOM|Mazda Reveals Mazda RX-VISION Concept|NEWS RELEASES". Mazda News Releases. Retrieved 22 February 2020.
  47. ^ "Mazda MX-30 – An electric car for the environment…. and the driver". Mazda Press EU. Europe: Mazda Public Relations. 2019-10-23. Retrieved 2020-05-27.
  48. ^ Swan, Tony (February 2013). "2014 Mazda 6 2.5L – First Drive Review". Car and Driver. Hearst Communications. Retrieved 2014-04-02. The engineering team nixed a CVT option early on and then decided against a dual-clutch type a little later in the planning process. The reasoning: A dual-clutch automated manual delivers sportier performance, but Mazda felt it was a little abrupt for everyday urban driving. As a result, the new self-shifter is a conventional automatic, with paddle shifters available in higher trim levels.
  49. ^ Halvorson, Bengt (2011-10-08). "Mazda Rejects DSGs, Redefines Automatic Transmissions Instead". Motor Authority. High Gear Media. Retrieved 2014-04-02.
  50. ^ Mazda. "MAZDA: SKYACTIV-BODY". Mazda. High Gear Media. Retrieved 2018-02-25.