Hybrid powertrain of the all-new Yaris

Our leadership in hybrid electric technology is built on more than 20 years, 15 million sales and half a billion kilometres of experience. The Toyota Yaris was the first to introduce hybrid power to the small car market, and now the all-new, fourth-generation Yaris builds on that reputation with a new, fourth-generation hybrid powertrain.

New Yaris

Fourth-generation hybrid electric system

In the development of this high-tech new powertrain, the engineering team focused on the dual qualities of efficiency and driver enjoyment, with tuning and calibration to suit European roads. This is explained for us in the video below by hybrid expert Keisuke Morisaki, a senior manager at Toyota Motor Europe.

Data underlines the extent of the team’s technical achievements. For example, overall efficiency has increased by 22%, a figure that would traditionally come at the expense of performance. Yet total system output is actually 16% greater at 114bhp, the 0-62mph time of 9.7 seconds represents a 15% improvement, and overtaking performance from 50 to 70mph has been cut by two seconds. CO2 emissions have dropped to 92g/km and the combined fuel economy figure is from 68.9mpg (WLTP cycle).

But one of the most immediately noticeable advancements is that the car’s all-electric EV capabilities have been transformed. It is now possible to drive in EV mode for much longer periods in urban traffic, and even maintain speeds of up to 80mph without assistance from the petrol engine. This endows the all-new Yaris with many of the benefits of a battery electric vehicle but at a lower price and no range anxiety.

Let’s now examine how each of the principal components in the hybrid system contribute to the new model’s enhanced efficiency and drivability.

M15A-FXE 1.5-litre hybrid engine

The all-new 1.5-litre hybrid engine (known internally by its M15A-FXE codename) is directly derived from the same TNGA engine family as the 2.0-litre unit employed in the Corolla and Toyota C-HR. It features a three cylinder configuration, long piston stroke, 14:1 compression ratio and super-fast combustion with optimal temperature and pressure control. This contributes to its exceptionally high thermal efficiency of 40%, which ensures that more of the energy potential from each drop of fuel is captured.

New Yaris

In common with all Toyota hybrid engines, the new M15A-FXE runs on the Atkinson combustion cycle, which keeps the intake valves open for longer in order to delay the compression stroke and improve efficiency. It offers a maximum output of 90bhp at 5,500rpm and peak torque of 120Nm at just 3,600rpm.

Hybrid transaxle

The hybrid transaxle (shown below) has been completely redesigned, adopting a new dual-axis structure that has reduced its size by 9.0%. This means that the two electric motor/generator units located within the transaxle now sit on their own shaft instead of being placed one behind the other. These motor/generators are known as MG1 and MG2.

New Yaris

MG1 starts the engine and generates power to charge both the hybrid battery and the 12V auxiliary battery. MG2, on the other hand, is the larger unit and is used to drive the vehicle through the front wheels. Benefitting from new segment-type coils on the stator, MG2 can deliver 59kW of power and 141Nm of torque at a maximum of 17,000rpm.

The transaxle also has a new ring gear-driven oil pump, which provides lubrication for both the gears and motor/generator units.

Lithium-ion hybrid battery

The all-new Yaris adopts a lithium-ion hybrid battery (below) that is not only more powerful but smaller and 12kg lighter than the nickel-metal hydride battery of the outgoing model. Voltage has risen from 144 to 177.6V although the number of cells has been reduced from 120 to 48. Current flow has also been significantly improved: output has increased by 50% while input, such as energy regeneration through the brakes, is 100% faster. Compact dimensions allow the battery to be located beneath the rear passenger seat so that luggage space is not compromised.

New Yaris

Power control unit

Often referred to as the PCU, this high-capacity power control unit is used to boost the voltage coming from the hybrid battery and convert it from direct to alternating current. The PCU uses transistor control for this inversion, and the efficiency of these transistors is optimised by arranging them vertically so they be cooled on both sides. More accurate heat control allows a higher frequency of current switching – up to 10,000 times a second – which makes a significant contribution to the system’s efficiency and transfer of power to the motor.

Power split device

This device is the heart of the hybrid system, governing the interaction between the aforementioned components. It enables the new Yaris to operate as a parallel hybrid with MG2 powering the car alone, or in combination with the hybrid petrol engine.

Learn more: Introducing the all-new Yaris
Learn more: Design features of the all-new Yaris
Learn more: Driving dynamics of the all-new Yaris
Learn more: Safety and equipment features of the all-new Yaris


    1. Hi Max,
      Thanks for your comment and your patience.
      The hybrid system in the new Yaris features a smaller, lighter transaxle containing a new, dual axis structure for the motor and generator. This has a low loss gear train with a smaller overall width. This parallel axis structure both increases the motor’s rotation speed and reduces its size.
      The new Yaris is also the first hybrid model to be fitted with 2 oil pumps, with the second allowing for better use of the main electric motor and meaning that the car can drive in EV mode for longer and at higher speeds of up to 80mph.
      It also improves fuel efficiency.

  1. Hi!! Can you tell me about the cooling system of the inverter??? And about the cooling of the battery??

    1. Hi Alexander,
      Thanks for getting in touch with us.
      You can access further information via New Car Features or the Repair Manual.
      Your nearest Toyota Centre may also be able to advise, but if not, information can be accessed using the following website: https://www.toyota-tech.eu/.
      However, access to this site is payable.

  2. We are about to replace a 22 year old Corolla hatch with an ordered Yaris Hybrid Luna. I fitted a trickle charger (Streetwise model SWTBC) to the former. The small unit fitted to the car and connected to the battery charges and sometimes discharges the 12v battery so is suitable for long term connection. A little plug from a brick type transformer goes into the fitted unit and plugs into the ac supply.
    I believe that the Yaris hybrid engine is started by power from the Li battery so a trickle charger cannot be connected. Is this correct? Is there anything that can be done to keep the Li battery charged if the vehicle is not used for several weeks/months?

    1. Hi Dave, thanks for your comment.

      The Yaris Hybrid is also started by the 12V battery. A trickle charger can be connected to this in the same was as your current Corolla and we would recommend to do so if you will not be driving it regularly.


      1. Many thanks for your swift reply. So I now know that the Hybrid engine is started by the 12v auxillary battery.

        Last time we flew on holiday we came back to a flattened 2000 Corolla battery (a cockpit light left on). For the new Yaris Hybrid replacement can the car be started by Jump leads, or a lead acid 12v jump starter, or a Li 12v jump starter, all of which we own. I am sure that some of these points may be covered by the Owners Manual but as I have only recently ordered the car I don’t have the manual. Many thanks for your help.

  3. According to the Yaris hybrid owners manual my new car needs 0W-8 oil. None of the local car accesory places seem to stock this (West Cork, Ireland). Is it essential or will 0W-10 or 0W-20 be ok for the car?

    1. Hi Dave,
      Your nearest Toyota Centre will be able to order in the oil your Yaris requires.
      Please contact them for further information.

    1. Hi Ken,
      Unfortunately, we do not have this information available.
      We apologise that we cannot help you further.

  4. Does the new Yaris engine fitted to UK cars use drive belts in its CVT design and do you have any more information on how this CVT works?

    Also, does the Yaris use a launch gear like some other models?

      1. That article describes the previous generation of CVT transmissions, that had a belt drive, unlike the latest. This Youtube video describes the more reliable beltless planetary gear ‘power-split’ CVT of the new (MK4) Yaris.

  5. On 17 January 2022 you recommended that I connect a trickle charger to my Yaris hybrid. Do I connect the charger to the special Jump start contact inside the fuse box and also to a suitable negative contact?

    1. Hi Dave,
      We would recommend following the instructions that are given.
      Alternatively, please contact your Toyota Centre to ensure these are connected correctly.

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