Since its launch last week, we've been pestering the nice folks at the Toyota PR department for more info on the GR Corolla. The automaker plans to provide a lot more technical information on the all-wheel-drive hot hatch closer to its launch this fall, but we did manage to get some details on its 1.6-liter three-cylinder.
With 257 hp in the GR Yaris, this engine, the G16E-GTS, was already the most powerful three-cylinder in production. (The Koenigsegg Gemera promises a three-cylinder that makes 600 hp on alcohol, though the car isn't in production yet.) For the GR Corolla, Toyota wanted more power to offset the extra weight compared to the Yaris, so it made some detail changes, bringing output to 300 hp and 273 lb-ft of torque.
The pistons are made from a stronger material, though Toyota is keeping mum on the exact alloy used, and the same is true for the exhaust valves. Those exhaust valves are larger, too, with stiffer valve springs. The ball-bearing turbocharger, which is integrated directly into the exhaust manifold, now runs 10% more boost. Top Gear reports that the GR Yaris' turbo runs around 20.3 psi of boost, meaning that in the GR Corolla, the boost is set to about 22.33 psi. That's a lot, so it's a good thing that GR Corolla also gets a higher capacity oil cooler. Increased boost pressure isn't the only source of the power increase, too. The central tailpipe on the GR Corolla helps reduce back pressure, further increasing horsepower.
Don't forget about all the neat things the G16E gets in both of its iterations, including oil-jet cooled pistons, a partially machined intake port, and a fuel system with direct and port injection. The engine is also largely hand-built, as is the rest of the GR Corolla, at Toyota's Motomachi plant.
This engine is a technical marvel, one of just a handful on the market offering 100 horsepower per cylinder, and its specific output of 187.5 hp/liter matches that of a Bugatti Chiron. A true piece of automotive exotica in the most humble of homes.
A car enthusiast since childhood, Chris Perkins is Road & Track's engineering nerd and Porsche apologist. He joined the staff in 2016 and no one has figured out a way to fire him since. He street-parks a Porsche Boxster in Brooklyn, New York, much to the horror of everyone who sees the car, not least the author himself. He also insists he's not a convertible person, despite owning three.
