TOYOTA / HYBRID KNOWLEDGE BASE

04 / UNDERSTANDING · THS / THS II

One principle.
Several generations of hardware.

What connects the engine, two motor-generators and wheels — and what changed between the first Prius, Prius α and today's hybrids. Read alongside the planetary gearset simulator, then use the generation table to put the model in context.

Starting point: Graham Davies's PowerTrain Components, last revised 26 June 2002. Its export first-generation Prius is the NHW11, within the “10-series” family. Specifications are checked against Toyota and ORNL publications. Sources and their scope are listed at the end. Reviewed .

Expanded with generation comparisons and primary technical publications. Dated owner advice retains its original scope. Sources and limitations.

First, put the old diagram in its year

“Prius 10” can mean the whole first-generation sedan family. The original Japanese NHW10 arrived in 1997; Toyota revised the system for the NHW11 in 2000. The 2001 US car discussed by Davies is this later version. The 1.5-litre engine, 273.6 V battery, 33 kW traction motor and silent-chain layout in that account describe its historical hardware, not every Prius. [1] [2] [3]

A useful reading order is still engine → motors → electronics → battery → power-split gearset → reduction → wheels. What needs updating is the specification attached to each component. A model name alone is insufficient: identify the full chassis code, year, market, HEV/PHEV and driven axles before comparing figures.

1. The combustion engine: an energy source

Toyota's original THS combines a petrol engine with an electrical path and a mechanical path to the wheels. Electric assistance lets the engine operate differently from a conventional engine tied to stepped ratios; the battery buffers changing demand. The engine is still needed for sustained energy supply in an ordinary HEV. “Self-charging” does not create energy: charge comes from fuel or recovered vehicle motion. [34]

Prius 10/11 and 20 use a 1.5-litre 1NZ-FXE; the 30 moves to the 1.8-litre 2ZR-FXE, also used in Prius α. The 50 retains a revised 1.8-litre engine; its quoted 40% thermal efficiency is a peak operating-point figure, not fuel-to-wheel efficiency on every trip. The fifth-generation Japanese range includes both 1.8-litre HEV and 2.0-litre M20A-FXS HEV/PHEV. Engine size does not identify the hybrid-system generation by itself. [4] [6] [12] [18]

The Atkinson-cycle description concerns the engine's effective compression/expansion strategy; it does not mean a different kind of planetary transmission. Engine efficiency, electrical losses and gearbox losses are separate quantities.

2. MG1 and MG2: names are not permanent jobs

In the familiar transverse power-split arrangement, the engine drives the planet carrier, MG1 connects to the sun gear and the ring gear belongs to the output path. MG1 starts the engine and supplies the reaction needed to control its operation. MG2 supplies wheel torque and recovers braking energy. “Generator” and “traction motor” describe typical roles: both machines can exchange mechanical and electrical power. [5]

The inverter controls a synchronous motor's stator currents in relation to the rotor. Rotation direction and energy-flow direction are different questions: a rotating machine can propel or brake. Negative MG1 rpm in a diagram therefore does not, on its own, tell you that the battery is charging. Toyota's THS II uses a permanent-magnet synchronous traction motor; an added rear motor need not have identical construction. [32]

Motor-shaft torque cannot be compared without gearing. A faster, smaller motor driving through a larger reduction can deliver substantial axle torque. Nor can engine and motor peak power simply be added: their peaks and available electrical supply need not coincide.

3. Inverter, boost converter and 12 V DC/DC

These are three different functions, even when packaged together in the power control unit (PCU). An inverter exchanges battery-side DC with the motor's three-phase AC. A boost converter raises the DC link voltage; the 2003 THS II announcement specifies up to 500 V. A separate DC/DC function supplies the low-voltage system. Battery voltage is consequently not the same thing as maximum motor-system voltage. [32] [33]

MG1-generated electricity can reach MG2 through the electrical bus without first being stored in the battery. The battery is a branch of that network, not a mandatory stop for every joule. In later systems, PCU packaging, switching losses and cooling have also evolved; the 2023 Corolla documentation describes a revised PCU and multi-axis transaxle. [33] [28]

4. Two batteries, two different purposes

The traction battery exchanges substantial power with the hybrid system. The auxiliary 12 V battery powers low-voltage equipment and enables the control system to wake up. A healthy traction battery does not make a discharged auxiliary battery irrelevant. The DC/DC converter supplies the low-voltage network when the hybrid system operates. [33]

NiMH and lithium-ion coexist across the family. In the 2011 Japanese Prius α, five seats mean NiMH and seven seats mean a compact lithium-ion pack in the centre console. The 50-series offers market-specific NiMH or lithium-ion packs. The 2021 Aqua adds bipolar NiMH on grades other than B. These are engineering variants, not a chronological rule that “newer always means lithium”. [10] [12] [24]

A plug-in has more stored energy and external charging: production ZVW35 has 4.4 kWh, ZVW52 has 8.8 kWh and the 2023 Prius Prime has 13.6 kWh. These published pack capacities are not a promise of usable energy or energy measured at the socket. kW measures power; kWh measures energy; Ah needs a voltage before it can be converted to energy. [8] [15] [21]

5. The power-split gearset: a constraint between three speeds

A simple planetary gearset has a sun, an internally toothed ring and a carrier holding the planets. Its meshing geometry gives the speed equation below. This is a kinematic relation: it does not decide battery current, engine load or efficiency.

General relation for a simple planetary setNs × ns + Nr × nr = (Ns + Nr) × ncN = tooth count; n = signed rotational speed; s = sun, r = ring, c = carrier. All speeds use the same reference direction.

For the 30-tooth sun and 78-tooth ring of the 2004 Prius, substitution gives nMG1 = 3.6 nICE − 2.6 nring. In that arrangement MG2 shares ring speed, matching the simulator's expression. With the engine stopped, increasing ring speed makes MG1 turn backwards. With ring speed held constant, changing MG1 speed changes engine speed. [5]

The effective continuously variable behaviour comes from controlling the coupled system, not from changing tooth counts. “e-CVT” here means an electrically controlled power-split transmission. The fundamental point is the extra degree of freedom: road speed does not fix engine rpm.

Torque and power must also be separated. In an ideal steady planetary set, tooth counts constrain the torque balance, but power is torque multiplied by angular speed. A fixed torque relation does not imply a fixed percentage of engine power taking the electrical path. A stationary shaft can exert torque while transmitting zero shaft power. This is why a speed animation alone cannot show fuel consumption or the complete power split.

6. The reduction stage changed more than once

The early silent-chain diagram should not be treated as a cutaway of a modern transaxle. The 2010 Prius has a separate planetary reduction between MG2 and the shared output, with a speed ratio of 58/22 ≈ 2.636. The power-split ring-to-axle ratio is a different number, approximately 3.27. Thus MG2 speed, power-split ring speed and wheel speed are three different quantities. [7]

In the 50-series, MG2 moves to a parallel-axis arrangement and parallel gears replace its planetary reduction. This removes the motor reduction planetary set, not the power-split planetary set. Toyota's 2.0-litre TNGA system is likewise explicitly described as a two-motor mechanical power-split type with parallel reduction gearing. [13] [26]

For a reduction magnitude i, output speed is input speed divided by i; ideal torque is multiplied by i. Actual output power is lower because of losses. Include every intervening stage and the tyre's rolling circumference before converting motor rpm into road speed; one inherited conversion constant cannot cover the whole family.

7. Differential, axles and an optional rear motor

The front differential lets the driven wheels turn at different speeds in a bend while the half-shafts carry torque to the hubs. It is a separate mechanism from the power-split gearset: one divides wheel speeds, the other couples the engine and electrical machines.

E-Four/AWD-i adds another branch. For example, the 2019 RAV4 hybrid AWD uses a separate rear electric motor. Do not draw a mechanical shaft from the front power-split gearset to that motor merely because the car is AWD. Rear-motor power and operating strategy vary by model; a Prius E-Four and an SUV AWD system are not interchangeable specifications. [30]

8. What conventional components disappeared?

In the ordinary Prius arrangement, engine starting and electrical generation are integrated into the hybrid machines; the low-voltage supply comes from DC/DC. There is no belt-and-pulley CVT or ordinary stepped shift sequence in this power-split transaxle. That does not make the transmission mechanically empty: gears, bearings, a differential and a parking mechanism still exist. [5] [33]

“No clutch” is too broad as a family-wide claim. ZVW52 adds a one-way device for dual-motor EV operation. Lexus multistage hybrids add a stepped mechanism, while Toyota HYBRID MAX uses a six-speed automatic and wet start clutch. The name Toyota Hybrid is not a guarantee of Prius hardware. [16] [29] [31]

Follow the energy, not just the arrows on a screen

Engine / carrierPower-split gearset / ringReduction / wheels
MG1PCU / DC busMG2 / reduction
Traction batteryPCU / DC bus
Original functional sketch for a transverse THS power-split system. The mechanical route couples engine and wheels through the power-split gearset; the electrical route links the machines through the PCU, with the battery as another branch. MG1 is mechanically attached to the sun gear of the power-split mechanism, and MG2 to the output directly or through reduction. This is not a packaging drawing, a fixed power allocation or the HYBRID MAX layout. [34] [33]
  • Electric motion: battery energy supplies traction. Engine-off does not imply that every internal shaft is motionless.
  • Engine running: a mechanical route and an electrical route can operate together; the battery may assist, absorb a surplus or exchange little net energy.
  • Deceleration: wheel power can be converted into stored energy. Conversion and battery acceptance have limits, so regeneration cannot replace every use of friction brakes.
  • Sustained demand: battery energy is finite. Peak combined output is different from the output available indefinitely after temperatures and charge limits intervene.

These are energy-balance examples, not a mode schedule for every car. Even the 2023 PHEV may start its engine despite remaining charge depending on system conditions and demand. Use the owner's manual for operational limits; the simulator does not implement those decisions. [20]

Which Prius are we talking about?

Dates below indicate introductions, primarily in Japan; export model years can differ. Codes identify representative variants, not every trim or homologation suffix. Component power and complete-system power are deliberately labelled separately.

Prius family: engine, electrical differences and the change that matters to the power-split gearset explanation
Family / introductionHardwareWhat to carry over from the old diagram
10 / 1997NHW10Original Japanese THS, 1.5-litre petrol engine and NiMH.The series/parallel principle starts here. Do not attach the later export car's complete specification to NHW10. [2]
11 / 2000NHW11Revised first generation, 1NZ-FXE 1.5; smaller, improved NiMH pack.The export 2001 Prius is the historical reference for Davies's article. [3] [1]
20 / 2003NHW20THS II / HSD, 1.5; MG2 50 kW; 201.6 V NiMH.Boost electronics and greater electric output; direct MG2/ring speed relation. Basis for this site's kinematic model. [4] [5]
30 / 2009ZVW301.8-litre 2ZR-FXE; MG2 60 kW; complete system 100 kW.Separate MG2 planetary reduction: motor rpm is no longer power-split ring rpm. [6] [7]
35 / 2012ZVW35 · PHVFirst production plug-in generation; 4.4 kWh lithium-ion.A branch of the 30 family, not the later ZVW52 dual-motor EV design. [8] [9]
α / 2011ZVW40W / ZVW41W1.8-litre THS II with reduction gear. Japanese 40W: seven seats / Li-ion; 41W: five seats / NiMH.Third-generation derivative; North American Prius v (five seats) and European Prius+ (seven) are regional relatives. “40” is not a new fourth Prius generation. [10] [11]
50 / 51 / 55 · 2015ZVW50 / ZVW51 / ZVW55Revised 1.8-litre system; MG2 53 kW. In the cited Japanese specification: 50 NiMH, 51 Li-ion, 55 E-Four NiMH.MG2 on another axis; parallel reduction gears. The power-split gearset remains. Export battery choices require their own catalogue. [13] [14]
52 / 2017ZVW52 · PHV / Prime1.8-litre plug-in; 8.8 kWh lithium-ion; dual-motor EV capability.A one-way device enables MG1 to help propel the car electrically. Not merely a bigger battery in an unchanged HEV. [15] [16] [17]
60 / 65 · 2023ZVW60 / ZVW65Japanese fifth-generation 1.8-litre HEV; 60 FF, 65 E-Four.The 60-series did not universally switch to a 2.0-litre engine. [18] [19]
60 / 65 · 2023MXWH60 / MXWH65M20A-FXS 2.0 HEV; 60 FF, 65 E-Four; Japanese system rating 144 kW.Same short number “60”, different engine prefix. Keep the full code when comparing cars. [18] [19]
61 / 2023MXWH61 · PHEV / Prime2.0-litre PHEV, FF; Japanese complete system 164 kW; 13.6 kWh published pack capacity.MG1/MG2 and a planetary e-CVT remain; do not reuse the 52's exact operating limits. [19] [20] [21]

What about “62”? The checked Toyota Japanese catalogue lists ZVW60/65, MXWH60/65 and MXWH61. It does not establish a Prius “62” variant. If “60/62” was intended to mean HEV/PHEV, the documented PHEV code here is MXWH61. We leave “62” unconfirmed rather than inventing a specification; a full model plate or another market's official document could resolve it. [19]

Beyond Prius: related does not mean identical

Compact and 1.8-litre applications

The Aqua/Prius c branch, beginning with the Japanese Aqua in 2011, uses a compact 1.5-litre THS II with reduction gearing. Toyota lists the regional names together. [36] The 2020 Yaris hybrid uses a three-cylinder 1.5-litre Dynamic Force engine; the 2021 Aqua brings bipolar NiMH and optional E-Four. Lexus CT 200h illustrates a 1.8-litre Atkinson-cycle hybrid application. Shared principles do not establish identical transaxles, cooling, battery packs or parts compatibility. [22] [23] [24] [25]

Corolla, C-HR and the larger transverse systems

THS II is a long-lived family name. The TNGA 2.0-litre system announced in 2018 has two-motor mechanical power split and parallel reduction. The European 2023 Corolla offers fifth-generation 1.8/2.0 systems; that generation number describes technology, not a Prius body. The 2.5-litre Dynamic Force THS II is another branch for larger transverse applications: the Japanese 2017 Camry, for example, uses A25A-FXS and a lithium-ion battery. [35] RAV4's 2019 2.5-litre hybrid illustrates how a separate rear motor adds AWD. [26] [27] [29] [30]

Toyota's wider inventory also includes Auris, Corolla Axio/Fielder, SAI, Harrier, Highlander/Kluger, Alphard/Vellfire and Estima. Inclusion in that list does not identify a transaxle: check the generation and powertrain of each model. It is a family map, not a parts-compatibility catalogue. [36]

Where the Prius explanation stops

Toyota's rear-drive multistage hybrid combines hybrid operation with a stepped transmission mechanism. HYBRID MAX is a different case again: the cited Crown pairs a turbocharged 2.4-litre engine, six-speed automatic, wet start clutch and rear electric drive; other Crown grades use THS e-CVT. Always identify the exact powertrain before applying claims such as “no shifts” or “no clutch”. [29] [31]

Three things to try in the planetary gearset simulator

  1. Set engine speed to zero and increase MG2. Watch MG1 reverse. This demonstrates a speed constraint, not unlimited real-world EV operation.
  2. Hold MG2 constant and vary engine rpm. The MG1 change is the extra freedom that makes the engine independent of one fixed road-speed ratio.
  3. Read the warning as a boundary of the educational model. Its 4,500 / ±6,500 rpm settings, simplified load-free operation and road-speed conversion are not a data sheet for all Prius generations.

Open the interactive gearset → The demonstration uses the direct MG2/ring representation. For later gearing, keep ring speed in the planetary equation and apply the actual motor reduction separately. It does not model torque, state of charge, thermal control, the 52's one-way device or E-Four.

From G21 to production Prius

The G21 project began in summer 1993, with the decision to make it a hybrid in November 1994. These are dates for a particular project, not the beginning of all Toyota hybrid research: the company describes gas-turbine hybrid work in the 1970s and a vehicle exhibited at the 1977 Tokyo Motor Show. The first Prius was announced on 14 October 1997; Japanese sales began on 10 December. [37] [33] [2]

Model year differs from calendar year. In one personal log, a 2001 Prius was ordered on 5 June 2000 and delivered on 9 September. This clarifies the US chronology without establishing every car's delivery date. [38]

72/28: torque shares and specific ratings

For an idealised steady-state planetary gearset with 78 ring teeth and 30 sun teeth, the engine-input torque shares are 78/(78+30) ≈ 72.2% and 30/(78+30) ≈ 27.8%. Torque directions require a consistent sign convention. These are reaction-torque ratios on the two branches, not a constant division of power or total wheel traction. Power also depends on angular speed: P = T × ω. Argonne's model shows different electrical flows at the same engine speed and torque. [39] [40]

For the tested 2004 Prius, ORNL lists a 201.6 V battery with 28 modules of 7.2 V and 21 kW output; MG1 can rotate up to 10,000 rpm. The 21 kW figure is not energy capacity in kWh. At maximum traction-motor demand, the account describes roughly 20 kW from the boost converter and 30 kW from the generator. One operating point does not define MG1's nameplate rating; the 10/18 kW labels in older diagrams are not treated here as verified ratings. [41]

Even tables for one generation need source labels. ORNL gives engine torque of 115 Nm at 4200 rpm and motor torque of 400 Nm over 0–1540 rpm. Toyota's UK 2003 publication instead gives 4000 and 0–1200 rpm respectively, and a 6.5 Ah battery. Combining the editions would create an unsupported universal specification. The undefined 1250 W/kg and 99-pound labels are likewise not used as a general specification. [41] [42]

For the 2010 Prius, ORNL distinguishes the MG2 reduction of 58/22 = 2.636 from the path between the power-split ring and differential: (77/24) × (55/54) = 3.27. The compared 2007 Camry has a 2.478 MG2 reduction; the 2004 Prius output path is 4.113. These figures belong to different transmission sections and vehicles. [43]

Full, Assist and changing electric-drive capability

Full Hybrid describes system capabilities rather than a unique transmission layout. Honda's 2006 Civic Hybrid publication describes low-speed steady cruising without combustion and with closed valves, while the crankshaft still turns mechanically. “Electric motor alone provides propulsion” therefore differs from “the engine is completely stationary”. The same document lists a 1339 cc engine, 158 V battery and 20 hp motor at 2000 rpm; this is historical IMA, not a modern Prius specification. [44]

Toyota also used different layouts. The 2001 Estima Hybrid had THS-C with a CVT; the 2001 Crown Mild Hybrid used a belt-connected THS-M motor-generator. The documented beltless Gen3 Prius cannot establish that every Toyota Hybrid is beltless. MG1 remains an electric machine rather than a “second battery”; no lifetime promise for spark plugs or the catalyst is made here. [33] [45] [46]

The UK 2017 Plug-in used a one-way device to let the generator act as a second traction motor. The European 2023 PHEV uses a different configuration without that device: a 120 kW motor and 164 kW system output. The US 2023 Prime release gives 220 net hp and an estimated 0–60 mph time of 6.6 s; the same model-year HEV has 194 hp / 7.2 s in FWD form and 196 hp / 7.0 s with AWD. The European PHEV's stated 0–100 km/h time is 6.8 s. The units and tests remain separate. [16] [47] [21] [48]

Sources and boundaries

The bibliography links primary Toyota/Lexus publications and an ORNL teardown report; Davies supplies the historical starting point. Source dates matter: a launch specification is evidence for that market and edition, not an automatically current service instruction. Both language versions use the same source set. Full reference metadata: sources.json; rights: notices.

  1. Graham Davies — PowerTrain Components · 2002-06-26Historical starting point: first-generation export Prius, not universal specifications.
  2. Toyota — Launch of the original Prius · 1997-10-14Original THS, 1.5-litre engine and series/parallel principle.
  3. Toyota — Leaner and Greener: Prius Gets Even Better · 2000-05-25NHW11 revision, 1NZ-FXE and revised NiMH battery; distinguish from NHW10.
  4. Toyota — Launch of the second-generation Prius · 2003-09-01THS II / Hybrid Synergy Drive, 1.5-litre engine, electric air conditioning.
  5. ORNL/TM-2006/423 — Evaluation of 2004 Toyota Prius Hybrid Electric Drive System · 2006-05Sections 2.2.2–2.2.6: power-split gearset members, 30/78 teeth, MG2 50 kW, 201.6 V pack, boost converter and electrical path.
  6. Toyota — Launch of the third-generation Prius · 2009-05-181.8-litre 2ZR-FXE, MG2 60 kW, 100 kW system, motor reduction gear.
  7. ORNL — Evaluation of the 2010 Prius, printed p. 41 (scan p. 50) · 2011-03Fig. 2.58: power-split gearset/output separation, MG2 reduction 58/22 = 2.636 and ring-to-axle reduction 3.27; no chain in the 2010 arrangement.
  8. Toyota UK — The New Prius Plug-in Hybrid (first generation) · 2011-09-13Production first-generation plug-in, 4.4 kWh lithium-ion pack.
  9. Toyota Japan — Prius PHV L, November 2012 catalogue · 2012-11ZVW35 production PHV identifier.
  10. Toyota — Launch of Prius α · 2011-05-13α/v/+ relationships, 1.8-litre THS II reduction gear, five-seat NiMH versus seven-seat lithium-ion.
  11. Toyota Japan — Prius α model catalogue · archiveZVW40W seven-seat and ZVW41W five-seat model identifiers.
  12. Toyota — Under the Hood of the All-new Prius · 2015-10-13Fourth-generation multi-shaft packaging, market-specific NiMH/lithium-ion batteries and 40% peak engine thermal efficiency.
  13. Toyota UK — Advanced Technologies for the Fourth Generation Prius · 2015-10-13MG2 planetary reduction replaced by parallel gears; 53 kW motor; this does not remove the power-split gearset.
  14. Toyota Japan — Prius Welcab specifications (base model codes) · 2017-11Japanese base vehicles ZVW50 NiMH, ZVW51 lithium-ion and ZVW55 E-Four NiMH; not a universal export-trim rule.
  15. Toyota UK — The New Toyota Prius Plug-in Hybrid · 2016-09-298.8 kWh pack and Dual Motor EV drive; launch specification for the 2017 model.
  16. Toyota UK — The New Toyota Prius Plug-in · 2017-02-06One-way device allows the generator to contribute to EV traction.
  17. Toyota Japan — Prius PHV specifications · 2021-06ZVW52 identifier and plug-in powertrain specification.
  18. Toyota — Launch of All-New Prius HEV in Japan · 2023-01-10Fifth generation; Japanese 1.8/2.0-litre HEVs, FF/E-Four, 2.0-litre system 144 kW.
  19. Toyota Japan — Prius catalogue, February 2025 · 2025-02ZVW60/ZVW65 1.8 HEV, MXWH60/MXWH65 2.0 HEV, MXWH61 PHEV; no 62 identifier in this edition.
  20. Toyota — Launch of All-New Prius PHEV in Japan · 2023-03-012.0-litre PHEV, 164 kW system, front-wheel drive; EV operation has engine-start exceptions.
  21. Toyota USA — Prime Time for More EV Miles with the All-New 2023 Prius Prime · 2023-04-0513.6 kWh battery; M20A-FXS, MG1/MG2 and planetary e-CVT retained in fifth-generation PHEV.
  22. Toyota — Launch of Aqua in Japan · 2011-12-26Compact 1.5-litre THS II with reduction gear; not a Prius 20 transaxle transplant.
  23. Toyota — All-new Yaris launch · 2019-12-201.5-litre three-cylinder Dynamic Force hybrid; distinguish hybrid e-CVT from gasoline Direct Shift-CVT.
  24. Toyota — Launch of All-New Aqua · 2021-07-191.5-litre Dynamic Force hybrid, bipolar NiMH (except B grade), E-Four availability.
  25. Lexus — Launch of CT 200h in Japan · 2011-01-121.8-litre Atkinson-cycle Lexus hybrid, illustrating a Prius-related application.
  26. Toyota — 2.0-liter Toyota Hybrid System (THS II) · 2018-02-26Two-motor mechanical power split, parallel reduction gears; separate 2.0-litre TNGA branch.
  27. Toyota UK — Corolla with fifth-generation hybrid electric technology · 2023-02-142023 European Corolla 1.8/2.0 hybrids; hybrid-system generation is not a Prius chassis code.
  28. Toyota UK — Technology for a new hybrid electric generation · 2023-04-14Fifth-generation Corolla: multi-axis transaxle, lithium-ion battery and revised PCU/cooling; specification boundaries.
  29. Toyota — Advancement of Toyota Hybrid System II · 2016-12-062.5-litre Dynamic Force THS II and separate rear-drive multistage hybrid branch.
  30. Toyota UK — World debut of the all-new RAV4 · 2018-03-282019 RAV4 2.5-litre hybrid, separate rear electric motor in AWD version.
  31. Toyota USA — The New Shape of Innovation: Toyota Crown · 2022-10-25Crown THS e-CVT versus HYBRID MAX turbo 2.4, six-speed automatic and wet start clutch: explicit exception to Prius architecture.
  32. Toyota — Development of the new THS II · 2003-04-17500 V boost circuit, permanent-magnet synchronous motor and variable engine/motor contribution.
  33. Toyota Technical Review Vol.54 — Development of High Output Power Control Unit for Hybrid SUVs · 2005Printed p. 50, PCU block diagram: boost converter, MG inverters and 12 V DC/DC are different functions.
  34. Toyota — Development of Prius and Hybrid Strategy · 2012Series/parallel concept and original THS motor/generator/power-split combination.
  35. Toyota — Completely Redesigned Camry · 2017-07-102017 Japanese Camry with A25A-FXS 2.5-litre Dynamic Force THS II and lithium-ion battery.
  36. Toyota USA — Worldwide Sales of Toyota Hybrids Top 6 Million Units · 2014-01-15Regional family names Aqua/Prius c and Prius alpha/v/+; wider hybrid model inventory, not proof of identical architecture.
  37. Toyota: The Story Behind the Birth of the Prius, Part 111.12.2017 · Selected document sections; vehicle, market and measurement limits accompany the cited claims.
  38. John1701a: Personal Log 103.01.2006 · Selected document sections; vehicle, market and measurement limits accompany the cited claims.
  39. Argonne: Tradeoff Between Powertrain Complexity and Fuel Efficiency08.06.2010 · Selected document sections; vehicle, market and measurement limits accompany the cited claims.
  40. Graham Davies: Power Split Devicesource edition · Selected document sections; vehicle, market and measurement limits accompany the cited claims.
  41. ORNL: Evaluation of 2004 Toyota Prius Hybrid Electric Drive System2006 · Selected document sections; vehicle, market and measurement limits accompany the cited claims.
  42. Toyota UK: Prius Paves The Way Ahead02.12.2003 · Selected document sections; vehicle, market and measurement limits accompany the cited claims.
  43. ORNL: Evaluation of the 2010 Toyota Prius Hybrid Synergy Drive System2011 · Selected document sections; vehicle, market and measurement limits accompany the cited claims.
  44. Honda: Hybrid System with 3-stage i-VTEC + IMA06.07.2005 · Selected document sections; vehicle, market and measurement limits accompany the cited claims.
  45. Toyota Canada: What's New, 2010 Prius2009 · Selected document sections; vehicle, market and measurement limits accompany the cited claims.
  46. John1701a: Personal Log 104302.12.2020 · Selected document sections; vehicle, market and measurement limits accompany the cited claims.
  47. Toyota Europe: All-New Prius Plug-in Hybrid2023 · Selected document sections; vehicle, market and measurement limits accompany the cited claims.
  48. Toyota USA: Hybrid Reborn, 2023 Prius16.11.2022 · Selected document sections; vehicle, market and measurement limits accompany the cited claims.