Next 86 will be 3 Cylinder Turbo Hybrid

According to the web site mag-x.jp, the next model 86 will drop the 2.0L Boxer engine for a 1.6L 3-cylinder straight turbo and combine it with a motor. It looks like a complete divorce from the Subaru BRZ. No indication whether it will be a THS or hybrid max setup. The article isn't explicit in stating it will be a 1.6L, but Toyota already has a 1.6L 3 Cylinder Turbo in their GR Yaris. I'm assuming it'll be that power plant mated as a hybrid max. Toyota also has a 1.5L THS system in their Yaris GR SPORT but that engine is naturally aspirated and it has the e-CVT. I'd assume the 86 will be using a 6-speed tranny like the Crown Platinum.

https://mag-x.jp/2023/02/24/21884/

partial translation:
"It's been a long time since Toyota started using the racetrack as part of its production vehicle development. In the past, the LFA and C-HR have participated in the Nürburgring 24 Hours race, and it goes without saying that they have excited not only motorsports enthusiasts but also many car enthusiasts. A recent example is the appearance of the Corolla Sport, which is equipped with a hydrogen engine.

While hydrogen engines are the focus of endurance racing, there are other efforts to go carbon neutral. One of them is the use of carbon-neutral fuel, which is being demonstrated using the 86/BRZ.


Focusing on this, the magazine X scoop team boldly predicts the next 86. It is highly likely that the powertrain will be a hybrid that combines a straight 3 downsizing turbo and a motor, and the FR lightweight platform that Toyota is developing for the chassis. If the components are switched to in-house production in the model change, there is a high possibility that assembly will be done at the company's own factory instead of outsourcing to Subaru."

 

https://motorillustrated.com/subaru-brz-and-toyota-gr86-getting-gr-yaris-power-report/112537/
More information on the move to put the GR Yaris powertrain in the GR 86. This time the divorce isn't complete as Subaru will drop the flat 4 (boxer engine) from the BRZ and place the GR Yaris powertrain in its place. In addition the 86 and BRZ will join the GR Yaris on its special platform as well. This combines the TNGA-B with a rear section from the TNGA-C. Lets look at the GR Yaris and its powertrain:

• 1.6L 3 cylinder turbo
• 192 kW (258 hp), 360 Nm (266 lb-ft) torque
• GR-FOUR all-wheel drive system
• Curb weight: 1280 kg (2822 lbs)
• Roof made up of carbon sheet molding compound (C-SMC)
• Aluminum used for the hood, front doors and hatch

The GR Yaris which has a power to weight ratio of 10.9 lbs/hp (6.67 kg/kW) ratio to a predicted 11 lbs/hp (6.9 kg/kW) for the BRZ/GR 86. The GR 86 is over 10 inches longer than the GR Yaris but if they add the 59 kW (79 hp) motor from the Yaris GR Sport it should put it over the top.

 

They are making it on the same platform as the GR Yaris so it'll have the same powertrain. To make matters more confusing the Yaris GR Sport has a hybrid system but it's not the same engine as the GR Yaris. I highly doubt they'll use the Yaris GR Sport hybrid system because it is a 1.5L THS with an eCVT. They'll stick with a 6-speed manual found on the GR Yaris and maybe make it a Hybrid Max system. The GR Yaris uses a single scroll turbo, so maybe they'll use the motor to make up for turbo lag like the Crown, but that little 3-cylinder is a lot quicker to get up to speed.

GR Yaris: GR Yaris: Born from the World Rally Championship
Yaris GR Sport: Yaris GR SPORT Joins Award-Winning Family

 

新型ハチロクは2025年デビュー!?　まさかのハイブリッドスポーツで300馬力オーバー確実 - 自動車情報誌「ベストカー」

So from bestcarweb.jp, it sounds like the official power plant for the GR86 will be a baby HybridMax with a 1.6L Turbo straight 3 instead of the 2.4L turbo straight 4.

Partial translation:
"　The next generation GR86 that will appear in the HEV that adds a motor to the inline 3, 1.6L turbo installed in the GR Yaris and GR Corolla. System output over 300ps is certain, and fuel efficiency is greatly improved while increasing power.

　The body size is around 4400mm in length and 1800mm in width, which is slightly larger than the current model, but still compact enough. Of course, the drive system will continue to be FR. The third generation will be developed under the leadership of Toyota, but the Subaru BRZ will also be sold as before."

No details on the motor to be inserted and the new GR86 will be introduced in 2025. The Subaru BRZ twin will also have the same power plant replacing their signature 2.4L Boxer engine. The current size of the 2023 GR86 is 4265mm (168 in.) long and 1775mm (69.9 in.) wide compared to the upcoming GR86 at 4400mm (173.2 in.) and 1800mm (70.9 in.) respectively. Toyota is switching the front wheel drive bias found on all current HybridMax to a rear wheel drive and keeping the 6-speed automatic all HybridMax have. If it has a manual it may be a faux manual that acts more like an override transmission than a true manual. I highly doubt the GR86 will be available in AWD-i like all current HybridMax vehicles. I'm not sure what they mean about greatly improving fuel efficiency either, since the current GR86 6-speed automatic gets 31 mpg highway and 25 mpg combined. Most HybridMax powertrains max out at around 30 mpg combined although that is a 20% improvement over the current boxer-powered GR86.