Mazda MX-5 Miata NB Japanese SP 1.6-Litre DOHC Engine
A 1.6-litre DOHC engine application in the Japanese Roadster SP, documented with five-speed manual or four-speed automatic transmission. Its engine code and complete production period remain unverified.
Engine application
The Japanese-market Mazda Roadster SP used an engine described by Mazda as 1600 DOHC. This denotes the nominal 1.6-litre class and double overhead camshafts. Mazda’s September 2003 lineup lists the SP with either a five-speed manual transmission (5MT) or four-speed electronically controlled automatic (4EC-AT). Mazda’s contemporary specification listing.
This record covers the SP engine application within the NB generation. The Japanese grade designation does not establish specifications for similarly named editions in other markets.
Development and documented chronology
Mazda’s July 18, 2000 announcement already lists the SP with a 1600 DOHC engine and both transmission choices. It places the application in the revised open two-seat Roadster range, whose changes included styling, body rigidity and cabin improvements. Mazda’s July 2000 announcement.
That release separately describes a revised 1.8-litre engine with Sequential Valve Timing. Its output, torque and valve-timing specification cannot be assigned to the SP’s 1.6-litre engine.
The two announcements establish availability in Japan in July 2000 and September 2003. These are calendar-date observations, not a verified production interval or export model-year designation.
Place in the Japanese range
The updated Japanese Roadster range went on sale on September 18, 2003. Mazda grouped the M, NR-A and SP under 1600 DOHC, while the RS, RS-II and VS used the 1800 DOHC designation. The SP illustrates the continued availability of the smaller engine with manual or automatic transmission during the NB’s development. Mazda’s September 2003 lineup.
For another application in the same generation, see the Japanese M 1.6-litre DOHC engine. Shared nominal displacement alone does not establish identical engine codes or calibrations.
Identification and evidence limits
The cited releases do not identify the SP’s engine code, exact displacement, output, torque, internal dimensions or engine assembly location. They also do not establish its complete production period or application-specific production total. Those details remain unverified; Japanese-market availability should not be treated as evidence of a particular manufacturing plant.