Toyota Tests 220-Horsepower Engine in GR86, Subaru Replacement Remains Unconfirmed

Toyota has put one of its own four-cylinder engines into an experimental GR86, replacing the boxer layout associated with the Subaru-powered sports car. The naturally aspirated 2.0-liter engine produces around 220 horsepower in the race prototype, but Toyota has not announced it for the next production GR86.

That boundary is central to understanding the test. The GR86 Future FR Concept is a development car competing in Japan’s Super Taikyu endurance series, not a production preview with a confirmed showroom powertrain. It gives Toyota a demanding environment in which to evaluate engine response, weight distribution and chassis geometry, while leaving the production decision open.

A different kind of GR86 experiment

Gazoo Racing ran the latest configuration at Okayama International Circuit with Toyota’s newly developed G20E inline-four under the hood. The engine belongs to a family of smaller, lighter four-cylinder units that Toyota is evaluating in several performance-car layouts.

The change is notable because this same GR86 prototype previously used a turbocharged three-cylinder derived from the 1.6-liter engine in the GR Yaris and GR Corolla. Toyota reduced that racing engine’s displacement to 1.4 liters, producing around 300 horsepower while using the car for synthetic-fuel testing.

The new configuration gives up roughly 80 horsepower compared with that earlier race setup. In return, removing the turbocharger and its associated hardware reduced mass at the front of the car and eliminated turbo lag. Gazoo Racing driver Kazuya Oshima told Japan’s Car Watch that the naturally aspirated engine revved higher than the development team expected.

Those changes favor immediacy rather than maximum output. A naturally aspirated engine does not need to wait for an exhaust-driven compressor to build boost, allowing torque to follow accelerator input more directly and predictably. For a lightweight rear-wheel-drive coupe, that response can make it easier for a driver to meter power while entering and exiting a corner.

The boxer engine still offers a packaging advantage

The G20E’s approximately 220-horsepower output is close to the current road-going GR86’s 228 horsepower. Similar peak numbers, however, do not make the engines mechanically equivalent.

The production GR86 uses a Subaru-sourced 2.4-liter boxer engine, whose opposing horizontal cylinders create a low, wide package. That architecture helps place engine mass lower in the chassis. An upright inline-four is narrower but lacks the boxer engine’s inherently low profile, so Toyota would have to evaluate installation height, center of gravity, cooling, exhaust routing and crash structure before approving such a change for a road car.

The prototype’s lighter front end therefore reflects the removal of turbo hardware from the previous racing configuration, not a complete public comparison against the current production boxer engine. Vehicle balance depends on the mass and position of the full installation, including intake, exhaust, cooling and emissions equipment.

Toyota is testing the chassis at the same time

The engine is only one part of the experiment. The Future FR Concept uses double-wishbone suspension at both ends, and engineers are trying different geometries. That makes it difficult to assign any change in handling solely to the powertrain: suspension pickup points, camber control and weight distribution are being developed together as a system.

Japanese accounts identify “Levin” as the prototype’s internal nickname. Toyota has also installed development four-cylinder engines in other configurations, including a Lexus IS tested at Fuji Speedway and performance prototypes with front- and mid-engine layouts. This broader work indicates that the company is using motorsport to determine where its new engine family fits best, rather than validating one predetermined GR86 specification.

A production switch would be consequential. The GR86’s two generations have been defined by cooperation between Toyota and Subaru and by the boxer engine’s role in the coupe’s packaging. Moving to a Toyota inline-four could alter that established formula, even if output remained near today’s level.

For now, the Okayama race test establishes something narrower but still meaningful: Toyota can run its naturally aspirated G20E in a front-engine, rear-wheel-drive GR86 prototype while gaining lower front-end mass than its earlier turbocharged race setup and more immediate throttle response. Whether those benefits justify replacing the Subaru boxer in a future showroom model remains an unanswered production decision.

By Thomas Caldwell — AMI’s senior editor for mechanical and mobility engineering, covering vehicle electronics, systems integration, electrification, chassis systems, propulsion, and safety policy.