CE Sakamoto

The GR Yaris and GR Corolla had arrived, but in motorsports, winning one race doesn’t serve as any guarantee that you’ll win the next one.

For a racing team, after a victory, the focus immediately shifts to improving for the next race.

So even though the GR Yaris and GR Corolla were ready to share with customers, our development work was not finished. Indeed, we saw this as the starting point for new development, a mindset that has driven the cars’ continued evolution from year to year.

In 2021, with the GR Corolla not yet released, we fielded a Corolla Sports that, under the hood, reflected the state of our GR Corolla development.

Ishiura has been assisting us as a driver since that time. With the hydrogen-powered Corolla, we took on the challenge of carbon neutrality as part of our multi-pathway approach to show that it could be achieved with internal combustion engines.

When it comes to motorsports, aspects such as exciting sounds and vibration become very important, and with that in mind, we have been optimizing this G16E-GTS engine (liquid-cooled inline three-cylinder DOHC turbocharged engine) for hydrogen fuel.

But racing is about more than just engines. We have also continued the evolution of various other elements, including the chassis, rigidity balance, and aerodynamic components.

In the first round of upgrades in 2023, we made minor improvements to joint rigidity, aerodynamics, and electrical properties to ensure the vehicle provides accurate feedback and responds as the driver intended.

Although we were not ready in time for 2024, in the early part of 2025, the model received significant upgrades to its driving dynamics, including increased engine torque, the addition of GAZOO Racing Direct Automatic Transmission (GR-DAT, an automatic transmission developed to be faster than a manual), improved suspension geometry and 4WD control, and advanced ABS.

To prepare for testing at the Nürburgring last November, we updated the late-2025 version with improvements to body rigidity and engine intake-air cooling.

This update is effectively what paved the way for the launch of the GRMN. I can say this now that we are here.

The origins of GR trace back to our Nürburgring efforts. Not the Nürburgring as a place, but as a road, undulating and demanding, on which we were able to forge our vehicles. Cars honed under those conditions become truly better ones.

Honing the GR Corolla at the Nürburgring, the birthplace of GAZOO Racing, has allowed us to identify its shortcomings and continue its evolution.

Ishiura

On a racetrack, more downforce makes for faster driving, but with touring cars like this you also tend to get lift (air pushing a vehicle upward), so suppressing that becomes crucial for improving handling stability.

The added aerodynamic performance parts look quite similar, but one aspect that feels a little extravagant to me is the painted fender ducts. They went so far as to paint over the carbon fiber.

As it turns out, simply using the exact same design as a racing car doesn’t automatically boost performance.

Grand Expert Osaka

Firstly, when we talk about making holes in the body, this might be done to vent the air swirling around inside the wheel wells, or in the case of the engine bay, expelling heat and increasing downforce.

When we tested the initial design, we were happy with how the car drove under normal conditions but found it lacking somewhat at higher speeds. As a result, we’ve made subtle tweaks, including to the shape of the vents.

Initially, we felt that larger openings would work better on the hood as well, but we ended up fine-tuning the dimensions and placement as we went.

The rear wing is also made of carbon fiber, but because it is affected by crosswinds, we gradually refined the shape by hand until we arrived at the current form.

Ishiura

As for the fender ducts, although they all appear to be open, some of the sections are actually closed.

That’s another really crucial point, and you cannot get to that configuration without actually testing it on the road. We put this GR Corolla through its paces, both on the racetrack and at our Shimoyama test course. It was always the two of us, Mr. Osaka and I, taking turns behind the wheel to see what he could find under normal conditions and what I felt pushing the car to its limits.

If it were just me and only worrying about the racetrack, I might be happy to sacrifice some straight-line stability to gain extra downforce, but focusing only on that would not work for the GR Corolla, and that’s where I could count on Mr. Osaka’s adjustments.

We worked to find the right balance between normal conditions and the upper limits. Doing the same kind of open-ended testing for aerodynamics revealed the trouble areas, which Mr. Osaka would then correct for me to evaluate again. As we repeated this process through many cycles, I came to realize how difficult aerodynamics is to get right.

You might improve one area, but then tackling the next one can completely throw off the balance. Trying to fit aftermarket parts onto this car is probably only going to make things worse (laughs).

CE Sakamoto

We actually made the GR Corolla Morizo Edition as a two-seater, and when we showed Morizo that sleek two-seater he said, “There’s a five-seater version too, right?” (laughs)

He did purchase one, but later had rear seats fitted and filed for a modification approval. During the talk show at Tokyo Auto Salon, he went so far as to call this five-seater version “the real Morizo Edition.”

Ishiura

It turns out Morizo had wanted a five-seater all along (laughs).

CE Sakamoto

We don’t plan to discuss the GR Corolla Morizo RR here in much detail today, but I will note that while the rear wing looks similar, it is actually slightly different.

Grand Expert Osaka

This one is set at a shallower angle. We’ve also added canards (small winglets mounted on the sides of the front bumper to create air vortices), with a meticulously crafted shape that incorporates a subtly upturned profile and ridges towards the rear.

CE Sakamoto

The rear wing has a five-step adjustment. Out of the factory, we set each component to achieve the best balance, and when customers tune the car, they can tweak settings to suit their preferences.

With the GRMN Corolla and the GR Corolla Morizo RR, in each case we were pursuing something quite different, from suspension tuning to the tires, and even the number of seats.