Toyota Toyota Hybrid System (THS): years, specs & known problems

By CarWhere Research · Updated

The Toyota Hybrid System is the series-parallel hybrid Toyota has sold in the US since the 2000 Prius. It pairs a gas engine with two motor-generators through a planetary CVT. The current fifth generation (THS 5) arrived in the 2023 Prius and Corolla Cross Hybrid and spread to the 2025 Camry and 2026 RAV4.

Every generation splits engine power through a planetary gearset with two motor-generators, so the car can run on the engine, the battery or both. Toyota branded the second-generation system Hybrid Synergy Drive with the 2004 Prius, moved to a 1.8L engine and 134 net hp for the 2010 Prius, and cut losses and weight for the 2016 Prius, whose 2ZR-FXE engine reached 40 percent thermal efficiency. Toyota's 2.5L hybrids (THS II) followed in the Camry, RAV4, Highlander and Sienna.

The fifth-generation system uses lighter, more compact motor-generators and lithium-ion batteries in its car applications. It powers the 2023+ Prius (194–196 hp), Corolla Cross Hybrid (196 hp), 2025+ Camry (225–232 hp), 2026 RAV4 (226–236 hp) and 2027 Crown XLE and Limited. Toyota engineers also describe the Tundra's i-FORCE MAX as part of the fifth generation.

Toyota Hybrid System (THS) at a glance

Toyota Hybrid System / Hybrid Synergy Drive: Prius generations through the fifth-generation THS 5 in the Prius, Camry, RAV4, Corolla Cross and Crown: model years, fuel and peak Toyota-published output by version
EngineModel yearsFuelPeak hpPeak torque (lb-ft)Documented problemsRecalls
Prius generations 1–4 (2000–2022)2000–2022Gasoline hybrid134—00
THS II with the 2.5L Dynamic Force engine (2018–2026)2018–2026Gasoline hybrid245—00
Fifth-generation THS 5 (2023–present)2023–presentGasoline hybrid23616310

CarWhere lists 1 documented problem and 0 NHTSA recalls for the Toyota Hybrid System (THS), each with a source.

Prius generations 1–4 (2000–2022)

The original Prius system, Hybrid Synergy Drive from 2004, the 1.8L third generation from 2010 and the low-loss fourth generation from 2016.

Prius generations 1–4 (2000–2022) specifications

Prius generations 1–4 (2000–2022): design facts (2000–2022)
SpecificationValue
US debutPrius arrived in the US in 2000[2]
Hybrid Synergy DriveIntroduced in 2004 on the second-generation Prius[1]
EPA combined mpg by generation41 (first), 46 (second), 50 (2010 third generation)[1]
2010 engine1.8L Atkinson-cycle four, 98 hp at 5,200 rpm[1]
2016 engine2ZR-FXE 1.8L, 40 percent-plus thermal efficiency[3]
2016 thermal efficiency40 percent maximum, helped by a large-volume EGR system[4]
2016 batteryLithium-ion in most grades (NiMH on the Prius Two non-Eco)[3]
Operating modesEngine only, battery only or both (series-parallel full hybrid)[1]

Prius generations 1–4 (2000–2022) horsepower and torque by year

Prius generations 1–4 (2000–2022): Toyota-published horsepower (hp) and torque (lb-ft) by model year and application
Model yearsApplicationHorsepower (hp)Torque (lb-ft)Source
2010Prius (system)24 hp more than the previous generation134—[1]

"—" means we could not confirm the figure from a primary source.

Which vehicles have the Prius generations 1–4 (2000–2022)?

Models and model years offered with the Prius generations 1–4 (2000–2022)
ModelModel yearsNotes
Prius (first generation)2001–2003US sales began in 2000
Prius (second generation)2004–2009
Prius (third generation)2010–2015
Prius (fourth generation)2016–2022

THS II with the 2.5L Dynamic Force engine (2018–2026)

Toyota's 2.5L hybrids before the fifth generation, using the A25A-FXS engine and an electronically controlled CVT. Toyota's 2023 Crown materials call this the fourth-generation THS.

THS II with the 2.5L Dynamic Force engine (2018–2026) specifications

THS II with the 2.5L Dynamic Force engine (2018–2026): design facts (2018–2026)
SpecificationValue
EngineA25A-FXS 2.5L Dynamic Force four[10]
TransmissionElectronically controlled CVT (ECVT)[6]
Multistage THS IIToyota's 2016 TNGA announcement describes a multistage THS II for 2.5L engines[11]
Crown namingToyota calls the 2023 Crown XLE and Limited system the fourth-generation THS[12]

THS II with the 2.5L Dynamic Force engine (2018–2026) horsepower and torque by year

THS II with the 2.5L Dynamic Force engine (2018–2026): Toyota-published horsepower (hp) and torque (lb-ft) by model year and application
Model yearsApplicationHorsepower (hp)Torque (lb-ft)Source
2021Camry Hybrid (system)208—[5]
2019RAV4 Hybrid (system)219—[6]
2020Highlander Hybrid (system)243—[7]
2021Sienna (system)245—[8]
2024Grand Highlander Hybrid (system)245—[9]

"—" means we could not confirm the figure from a primary source.

Which vehicles have the THS II with the 2.5L Dynamic Force engine (2018–2026)?

Models and model years offered with the THS II with the 2.5L Dynamic Force engine (2018–2026)
ModelModel yearsNotes
Camry Hybrid2018–2024
RAV4 Hybrid2019–2025
Highlander Hybrid2020–present
Sienna2021–present
Grand Highlander Hybrid2024–present
Crown XLE, Limited2023–2026

Fifth-generation THS 5 (2023–present)

The current system, with lighter and more compact motor-generators and lithium-ion traction batteries in its car and crossover applications. AWD versions add a rear motor (Electronic On-Demand AWD).

Fifth-generation THS 5 (2023–present) specifications

Fifth-generation THS 5 (2023–present): design facts (2023–present)
SpecificationValue
Motor-generatorsLighter and more compact than the previous system[15]
TuningDraws more battery power during acceleration to hold engine rpm down for a more natural feel[15]
2026 RAV4 engine and motorsA25A-FXS with MG1 and MG2; MG2 torque 153 lb-ft; rear MGR 89 lb-ft on AWD[16]
Prius engineM20A-FXS 2.0L[2]
Truck applicationToyota engineers describe the Tundra i-FORCE MAX as fifth-generation THS[17]

Fifth-generation THS 5 (2023–present) horsepower and torque by year

Fifth-generation THS 5 (2023–present): Toyota-published horsepower (hp) and torque (lb-ft) by model year and application
Model yearsApplicationHorsepower (hp)Torque (lb-ft)Source
2023Prius FWD / AWD (system)194 hp FWD, 196 hp AWD196—[13]
2023Corolla Cross Hybrid (system)196—[14]
2025Camry FWD (system)225—[15]
2025Camry AWD (system)30 hp more than the previous mechanical-AWD Camry232—[15]
2026RAV4 Hybrid FWD (system)Torque is engine only226163[16]
2026RAV4 Hybrid AWD (system)Up from 219 hp; torque is engine only236163[16]

"—" means we could not confirm the figure from a primary source.

Which vehicles have the Fifth-generation THS 5 (2023–present)?

Models and model years offered with the Fifth-generation THS 5 (2023–present)
ModelModel yearsNotes
Prius2023–present
Corolla Cross Hybrid2023–present
Camry2025–presentHybrid-only
RAV4 Hybrid2026–present
Crown XLE, Limited, Nightshade2027

Fifth-generation THS 5 (2023–present) problems and what to check

Loose bolt inside the hybrid inverter (2025–2026 Camry, 2026 Corolla Cross Hybrid) (2025–2026)

Major repair

In December 2025 Toyota recalled about 55,000 US vehicles, certain 2025–2026 Camry and 2026 Corolla Cross Hybrid models, because a bolt inside the hybrid inverter can loosen. Toyota says this could lead to a loss of motive power or a fire while the vehicle is on. The repair is free.[18]

Symptoms

  • Hybrid system warning lights
  • Loss of drive power while the vehicle is on

Check before buying

  • Run the VIN at Toyota.com/recall or nhtsa.gov/recalls
  • Ask the seller or dealer for proof the inverter recall work was completed

Program: Toyota safety recall announced Dec. 16, 2025; free remedy at Toyota dealers

Toyota Hybrid System (THS) issues by model

The same engine shows up on these known-issues pages, with model-specific details.

Related Toyota research

Confirm a car really has the Toyota Hybrid System (THS).

The engine a Toyota left the factory with is part of its build record. The CarWhere Toyota build sheet reconstructs factory colors, options and packages from licensed VIN-level build data — availability is checked free, and it is $9.99 only when detailed build data is found for that VIN.

Toyota build sheet by VIN

Frequently asked questions

What generation is the Toyota hybrid system in the 2025 Camry?

The 2025 Camry uses the fifth-generation Toyota Hybrid System (THS 5) with a 2.5L engine, rated at 225 hp with FWD and 232 hp with Electronic On-Demand AWD. It is the first Camry sold only as a hybrid.

Does the 2026 RAV4 have the fifth-generation hybrid?

Yes. Toyota says the 2026 RAV4 Hybrid moves to its fifth-generation powertrain with the A25A-FXS 2.5L engine, rated at 226 hp (FWD) and 236 hp (AWD). The 2026 RAV4 Plug-in Hybrid uses a separate sixth-generation plug-in system rated at 324 hp.

Is Hybrid Synergy Drive the same as the Toyota Hybrid System?

Yes. Toyota introduced the Hybrid Synergy Drive name in 2004 on the second-generation Prius for the same series-parallel system, which combines an engine and two motor-generators through a planetary CVT.

Which Toyotas have the fifth-generation hybrid?

The 2023+ Prius, 2023+ Corolla Cross Hybrid, 2025+ Camry, 2026+ RAV4 Hybrid and 2027 Crown XLE, Limited and Nightshade. Toyota engineers also describe the Tundra's i-FORCE MAX as part of the fifth generation.

What is the hybrid warranty on a Toyota?

On recent models Toyota covers hybrid-related components for 8 years/100,000 miles and the hybrid battery for 10 years/150,000 miles from first use, transferable across owners.

Sources

Ratings are Toyota-published figures as cited; descriptions are CarWhere’s own summaries of the sources below. Repair costs appear only where a source states them and vary by shop and region.

  1. All-New Third Generation Toyota Prius Raises the Bar for Hybrid Vehicles Again — Toyota Motor North America (pressroom.toyota.com)
  2. Electrified Trailblazer: The Toyota Prius Celebrates 25 Years in the U.S. (2026 Prius) — Toyota Motor North America (pressroom.toyota.com)
  3. Return of the Disrupter: All-New 2016 Toyota Prius — Toyota Motor North America (pressroom.toyota.com)
  4. Toyota Unveils Advanced Technologies in All-New Prius (Oct. 13, 2015) — Toyota Motor North America (pressroom.toyota.com)
  5. Clear-Cut Leader: The 2021 Toyota Camry Adds More Variants While Advancing Safety (July 15, 2020) — Toyota Motor North America (pressroom.toyota.com)
  6. All-New 2019 Toyota RAV4 Breaks the Mold for the Segment It Created — Toyota Motor North America (pressroom.toyota.com)
  7. Toyota's Fourth Generation 2020 Highlander Redesigned from the Ground Up (Dec. 18, 2019) — Toyota Motor North America (pressroom.toyota.com)
  8. 2021 Toyota Sienna Hits Dealerships This November (Oct. 27, 2020) — Toyota Motor North America (pressroom.toyota.com)
  9. 2024 Toyota Grand Highlander Touches Down in Driveways This Summer (May 30, 2023) — Toyota Motor North America (pressroom.toyota.com)
  10. Toyota Highlander Hybrid owner's manual: Maintenance data (A25A-FXS specifications) — Toyota Motor Sales, U.S.A. (owner publications)
  11. Toyota Develops TNGA-based Powertrain Units (Dec. 6, 2016) — Toyota Motor Corporation (global.toyota)
  12. Toyota Crown Returns to the US with Bold Style and New Hybrid MAX Powertrain — Toyota Motor North America (pressroom.toyota.com)
  13. Hybrid Reborn: 2023 Toyota Prius Revealed — Toyota Motor North America (pressroom.toyota.com)
  14. Revealed: First-Ever 2023 Toyota Corolla Cross Hybrid — Toyota Motor North America (pressroom.toyota.com)
  15. Toyota Camry Goes Exclusively Hybrid Plus a New Look and More Technology — Toyota Motor North America (pressroom.toyota.com)
  16. The Next Adventure Begins: 2026 RAV4 Arrives this Winter (Oct. 22, 2025) — Toyota Motor North America (pressroom.toyota.com)
  17. A New Breed of Hybrid: The 2022 Tundra i-FORCE MAX — Toyota Motor North America (pressroom.toyota.com)
  18. Toyota Recalls Certain Toyota Camry and Corolla Cross Hybrid Vehicles (Dec. 16, 2025) — Toyota Motor North America (pressroom.toyota.com)

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Independent reference compiled by CarWhere — not affiliated with or endorsed by Toyota Motor Corporation, Toyota Motor North America or any Toyota distributor. Toyota, TRD, i-FORCE MAX, Hybrid Synergy Drive and the model names are trademarks of their owners.