Toyota Prius: from the 1997 sedan to the 2003 hatchback
Trace the original Toyota Prius from its 1997 Japanese launch to the 2003 redesign, with factory sources explaining dates, body style, and THS II.
Answer first
Toyota announced the first Prius sedan on October 14, 1997, for Japanese sales beginning December 10. The second generation arrived in Japan on September 1, 2003, combining a five-door body with the revised THS II hybrid system.
The 1997 Prius launch date: announcement versus sales
Toyota's October 1997 announcement gives a specific future on-sale date: December 10 in Japan. Those dates describe different events. An October unveiling and December retail introduction can both be correct; a timeline that labels either simply 'launched' loses useful detail.
Toyota's company-history archive adds another boundary: export began in 2000. That was the expansion of the first generation into overseas markets, not the invention of a second generation. When identifying an early Prius, record the market alongside the year and distinguish announcement, retail introduction, and model-year labeling.
1997: a sedan built around two sources of power
The original Japanese Prius paired a 1.5-liter gasoline engine with an electric motor under Toyota Hybrid System control. Toyota described automatic engine shutdown at a standstill and recovery of energy during deceleration and braking. Its exterior followed a three-box sedan layout, with a separate trunk rather than the later hatchback profile.
This is the important historical combination: the body was recognizable as a small sedan, while the powertrain coordinated combustion and electric propulsion. The hybrid system was the central engineering change; the familiar wedge-shaped Prius silhouette came later.
2003: what THS II changed
Toyota announced THS II in April 2003, ahead of the replacement Prius. Its technical release describes a higher-voltage power-control circuit, improvements to the battery and engine, and a motor with 1.5 times the previous output. Toyota presented that package under the Hybrid Synergy Drive concept.
The system could operate on electric-motor power alone when engine operation would be inefficient. That capability should not be confused with a claim of long electric-only range: the release describes operating strategy, not a promise that the car could replace a battery-electric vehicle. Nor should a system voltage figure be read as the battery's nominal voltage; Toyota specifically describes a circuit that boosts voltage.
The redesign made the hybrid visibly different
The September 1, 2003 Japanese launch release describes a new five-door package, a triangular cabin-centered shape, and a longer wheelbase. It reports a drag coefficient of 0.26. Together, the body and cargo-access changes explain why the second-generation car looks so different from its predecessor.
The same release includes Japanese grades and market-specific equipment. Do not transfer every listed option to an export-market car merely because its shape matches. A generation identifies a broad design family; the local brochure and exact specification still determine what an individual version offered.
How to use these dates when researching a car
Start with the vehicle's market and identity, then find a period source for that market. Keep the original document's publication date separate from the sales date it describes. If two sources disagree, check whether one is describing an announcement and the other deliveries before assuming one must be wrong.
For a generation comparison, separate three questions: when the design changed, how the powertrain changed, and which equipment applied locally. This article covers the original sedan and its 2003 Japanese replacement; it does not claim to document every export specification or later Prius generation. The illustration is an original body-style diagram, not an archival photograph or an exact styling reference.
Evidence ledger
Primary sources
Time-sensitive claims were checked against the sources below on September 7, 2026. The linked source controls.
- Toyota Motor CorporationOctober 14, 1997 announcement: Japanese sales to begin December 10
- Toyota Motor Corporation — 75 Years of ToyotaFirst-generation vehicle lineage: export began in 2000
- Toyota Motor CorporationApril 17, 2003 THS II technical announcement
- Toyota Motor CorporationSeptember 1, 2003 Japanese launch: five-door Prius with THS II