How Toyota Made an Automatic Worthy of the GR Corolla

GR Corolla chief engineer Naoyuki Sakamoto explains what makes the GR Direct Automatic Transmission so interesting.

Photo by: Toyota

By: Chris Perkins

Oct 23, 2024 at 11:30am ET

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The Toyota GR Corolla’s new automatic transmission came seemingly out of nowhere. We first learned of it last October, when Toyota chairman Akio Toyoda talked about its development in a company magazine, and a few months later, it made its debut in the updated GR Yaris. Now we get the Gazoo Racing Direct Automatic Transmission (DAT) here in the States with the 2025 GR Corolla, and it’s a remarkable thing.

This eight-speed auto is based on a standard Toyota transaxle that’s been in production for eight years now. But other than the case itself, it’s almost entirely bespoke for Gazoo Racing.

"To put an automatic transmission into a sports car, the response is important," says Naoyuki Sakamoto, chief engineer of the GR Corolla. "So, we changed the solenoid valves and increased the durability of the friction material in the clutches. Those are the main things."

Sakamoto says Toyota also changed the gear ratios compared to the standard Toyota eight-speed. The overall spread from first to eighth is shorter, and each individual ratio except 5th is shorter as well. Compared with the GR Corolla’s six-speed manual, 1st is the same, 2nd through 5th are shorter, and 6th is longer. Plus, you get two additional ratios for high-speed cruising.

It’s a tiny package, too, with just two planetary gearsets—one is a Ravigneaux type, a planetary gearset with two sun gears and two sets of planet gears—and four clutches. There’s a torque converter with a lockup clutch that engages very quickly to give a more direct connection between throttle pedal input and engine response. And integrated to the case is a Torsen limited-slip differential. (All GR Corollas now have front and rear slippy diffs standard, while on the old base model, they were optional.)

Toyota’s been working on this transmission for a few years now, and it’s raced it extensively in Japan, both in GR Yaris rally cars and Yarises and Corollas in the Super Taikyu endurance series. In competition, Toyota has all the drivers use automatic mode, which helped inform the shift programming of the road car.

"Each time we got a complaint from a driver 'downshift timing isn’t good,' or something like that, we analyzed the data and changed the logic to understand what the driver wants," Sakamoto says. In our first impressions on the Charlotte Motor Speedway "Roval," the transmission always chose the correct gear in automatic mode. If you want, you can leave it in "D," never touch the paddles and you won’t be worse off.

Toyota

Toyota claims the GR DAT shifts in under 300 milliseconds, a little quicker than two unnamed competitors' eight-speed dual-clutches. In our limited experience with the new GR Corolla, it’s hard to want faster shifts. The DAT might not have quite the snap of a dual-clutch, but we’re talking very fine margins here. It’s as good as any traditional automatic out there.

But as interesting as the "how" is the "why." According to Toyota’s in-house paper, the Toyota Times, it was developed at the behest of Akio Toyoda. "One day, [Toyoda] remarked that not many people can drive a manual, and said he wanted 'to spread the joy of driving,' said GR Yaris chief engineer Naohiko Saito. "That’s how we got started working on DAT. We started figuring out the concept in the second half of 2020."

While Toyota expects the automatic to only make up 20 percent of GR Corolla sales in the US, in Japan, 70 percent of drivers are only licensed to drive automatic transmissions. So there’s a big market out there.

What do you think?

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And it is a better transmission for racing, with much quicker shift times than any manual. The GR DAT will be used in Toyota’s new GR Corolla TC car, too.

There is a large contingent that probably doesn't care that the GR Corolla now has an automatic, and I could see people being hostile to the thought of this hot hatch with fewer than three pedals. But there is no doubting that the GR DAT broadens the GR Corolla’s appeal, and that Toyota did things right here.