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Mazda · ND · Japanese S · Engine /MANUFACTURERS/MAZDA/MX-5-MIATA/ND/JAPANESE-S/SKYACTIV-G-1-5

Mazda MX-5 Miata ND Japanese S SKYACTIV-G 1.5 Engine

The Japanese ND Roadster S paired the direct-injection SKYACTIV-G 1.5 petrol engine with a six-speed manual gearbox, applying Mazda’s engine architecture to a lightweight sports car.

Identity and application

The SKYACTIV-G 1.5 direct-injection petrol engine powered the Japanese S variant when the fourth-generation Mazda Roadster went on sale in Japan on 21 May 2015. Roadster was the Japanese name for the MX-5. S identified an equipment grade, not a distinct engine family.

The S combined this engine with rear-wheel drive and a six-speed SKYACTIV-MT manual transmission in a two-seat soft-top. Unlike the higher S Special Package and S Leather Package grades, the launch S had no automatic option. Their optional manual-transmission i-stop and i-ELOOP equipment should not be attributed to the S. Mazda’s Japanese launch announcement.

Original 2015 engine specification

Mazda’s engineering paper documents the original Roadster engine as follows:

  • Displacement: 1,496 cc.
  • Bore × stroke: 74.5 × 85.8 mm.
  • Compression ratio: 13.0:1.
  • Maximum power, JIS net: 96 kW at 7,000 rpm.
  • Maximum torque, JIS net: 150 N·m at 4,800 rpm.
  • Maximum engine speed: 7,500 rpm.
  • Fuel grade: premium petrol.

These are the original Roadster specifications, not universal figures for every SKYACTIV-G 1.5 application or subsequent revision. Mazda Technical Review, Table 1.

Development for the Roadster

Derived from the Axela’s SKYACTIV-G 1.5, the Roadster engine received extensive changes for rear-wheel drive and higher-speed operation. These included a fully counterweighted steel crankshaft, revised intake and exhaust systems, and changes to the cylinder head, block, cooling layout and oil pan. The development illustrates how shared engine architecture could support a substantially adapted sports-car application. Mazda’s engineering account.

The engine’s position behind the front axle and its lowered mounting contributed to the ND’s balance and agility. In the S, the manual transmission completed the basic Japanese launch powertrain. Mazda’s launch description.

Production and introduction

Mazda’s announcement dated 5 March 2015 reported the start of fourth-generation MX-5 vehicle production at Ujina Plant No. 1 in Hiroshima, Japan, initially for the Japanese market. This identifies vehicle assembly, not the engine’s manufacturing plant or a separate S-engine production start. Mazda’s production announcement.

The provisional expectation of Japanese sales around June was superseded by the confirmed 21 May launch. These are calendar dates, not overseas model-year designations. Japanese sales announcement.

2018 development and scope

On 7 June 2018, Mazda announced revised Japanese Roadster models for sale from 26 July. The S retained the SKYACTIV-G 1.5 and six-speed manual. Mazda described combustion improvements, torque maintained or increased across the operating range, and improved response and environmental performance. The original 2015 figures therefore should not be assumed to describe every later S.

The same announcement separately identifies the Japanese Roadster RF with SKYACTIV-G 2.0 power; its specifications do not belong to this 1.5-litre soft-top application. These sources establish introduction and later development, but not an application-specific production total or end date. Mazda’s 2018 announcement.

See the parent Japanese S variant and the broader ND generation. Other catalogued applications include the Japanese S Leather Package SKYACTIV-G 1.5 and Japanese NR-A SKYACTIV-G 1496 cc, retained as separate grade-specific engine records.

Sources