A Toyota GR Corolla in Supersonic Red driving quickly down a dirt road.

2023 Toyota GR Corolla – R&D Vehicle Profile

When Toyota announced that the GR Corolla was coming for the 2023 model year, we were quick to take note. After a few years of seeing countless videos and reviews of the venerable yet unobtainable GR Yaris—a model not available to the American market—we’d developed a bit of an itch. Once we heard that Toyota was finally bringing a rally-inspired turbocharged hot hatch with all-wheel drive and three pedals to the US, we set out to secure our latest R&D vehicle.

 

After hundreds of hours of research and development to design new performance applications, we want to share some of the products we’ve made for the GR Corolla. But first, let’s take a look at the car itself.

Vehicle Review

An image of a 2023 Toyota GR Corolla in front of a covered bridge.

The wait for the GR Corolla was a long one, but it was made even longer by then CEO, Akio Toyoda. After personally testing the vehicle prototype, Toyoda, who also goes by the racing moniker Morizo, didn’t feel the vehicle was up to par. He urged Toyota engineers to take it up a notch, telling them to make it “wider and wilder.” They say good things come to those who wait, and this was definitely the case when it came to the GR Corolla. 

 

Powered by the same 1.6-liter G16E-GTS engine found in the GR Yaris, Toyota engineers managed to get an impressive 300 horsepower and 273lb-ft of torque out of the little inline-three motor, making it one of the most powerful three-cylinder engines in the world. This impressive power output is in part due to a turbocharger capable of 26.3 psi of boost and a unique three-tailpipe design—one for each cylinder—for reduced backpressure. Peak torque comes in at 3000-5500 rpm while maximum horsepower sits around 6500 rpm.

The back of a 2023 Toyota GR Corolla, showcasing the three tailpipes.

While new vehicles with manual transmissions aren’t impossible to find, they’re becoming rarer and rarer by the year. That’s why we were thrilled to see the GR Corolla came equipped with a 6-speed stick shift. While the clutch is a bit heavy for our liking, rowing gears in the GR Corolla is a pleasure with a notchy shifter feel and tight gearbox. The intelligent manual transmission system (iMT) makes downshifting into tight corners a breeze with automatic rev-matching, but the system is easy to disengage if you feel like doing some good old-fashioned double clutching.

 

Further down the powertrain we find the GR Corolla’s party trick—the all-wheel drive system with three selectable torque splits. The system defaults to a 60:40 bias front/rear split for a comfortable yet capable daily driving experience. For a more sporty feel, the 30:70 configuration makes the vehicle a bit more agile and tail-happy. But when you really need the vehicle to ride on rails and stay planted, such as spirited backroad sprints and track days, opt for the 50:50 torque split.

A 2023 Toyota GR Corolla in Supersonic Red with fall foliage in the background.

With such a potent and impressive powertrain, the folks at Gazoo Racing designed an extremely capable handling and suspension system to get the most out of the vehicle. Built for precision and agility, the GR Corolla boasts MacPherson-type strut front suspension and a double-wishbone multilink rear suspension. The technicians at the dedicated GR Factory in Motomachi also include extra body welds to increase chassis rigidity. The combination of these aspects provide a responsive but reasonably comfortable handling experience.

 

Riding on 18-inch wheels with 235/40R18 Michelin Pilot Sport 4 tires, the GR Corolla has a firm grip on the road. It comes equipped with high-performance ventilated and slotted brake rotors designed to resist fade under heavy use.

The wheel of the 2023 Toyota GR Corolla.

After putting over 10,000 miles on the car, we found the 2023 GR Corolla to be what Morizo was imagining when he told his engineers to go back to the drawing board—a true driving enthusiast’s vehicle. While the GR Corolla can play tame in regular traffic, it’s a thin veil and the vehicle doesn’t hide the fact that it’d prefer to be rowdy on a winding backroad. It’s a truly engaging vehicle in a way that is becoming increasingly hard to come by these days, and we’re very excited to see what future models have to offer.

A 2023 Toyota GR Corolla next to a body of water.

That being said, our engineers are dedicated to pushing the limits with each and every vehicle that comes into our facility. While the GR Corolla is remarkable in stock form, there’s always going to be room for improvement. Let’s take a look at some of the ways we’ve worked to make the GR Corolla even better. 

Dan, our engineer, installing our Performance Intercooler on a 2023 Toyota GR Corolla.

As Toyota’s GR Corolla continues to captivate automotive enthusiasts with its rally-inspired design and the record-setting G16E-GTS engine, our engineers stepped up to enhance its performance with a meticulously designed intercooler. The factory intercooler, though efficient, left room for improvement. We focused on creating a direct-fit bar-and-plate intercooler that boasts a 52% increase in core volume and a 24% increase in fin surface area. By incorporating anodized aluminum ducting and maintaining a minimal pressure drop, the new intercooler improves airflow and cooling efficiency, ensuring the turbocharger can perform optimally under intense driving conditions.


Rigorous testing confirmed the effectiveness of our intercooler, which reduced outlet temperatures by up to 38.5°F and demonstrated minimal pressure drop, preventing undue strain on the turbocharger. Dyno results highlighted a notable power increase, with peak gains of 8.52 horsepower and 9.01 ft-lbs of torque. Designed for reliability and durability, this performance intercooler enables GR Corolla owners to push their vehicles harder without sacrificing engine longevity. This upgrade is an essential enhancement for drivers seeking to maximize the potential of the GR Corolla's innovative powertrain.

The front of a 2023 Toyota GR Corolla.

The Toyota GR Corolla’s powerful 1.6-liter G16E-GTS engine delivers incredible performance but demands efficient cooling during aggressive driving. To address this, our engineers developed the Performance Aluminum Radiator for the 2023+ GR Corolla, replacing the stock unit’s plastic end tanks with durable aluminum. Featuring a 40mm thick core with a 51% increase in core volume, this radiator provides significantly improved cooling capacity while maintaining compatibility with stock components. Mitch, one of our engineers, carefully designed the radiator to optimize airflow with a louvered fin structure and foam strips, ensuring maximum heat dissipation for consistent performance.


Additional enhancements include strutted tubes for durability, reinforced intercooler mounts for reliability during performance upgrades, and an extended drain with a magnetic slotted plug for convenient maintenance. Designed for a direct-fit installation while retaining the stock A/C condenser shrouding, this radiator offers a seamless upgrade for GR Corolla owners. With its improved cooling efficiency and robust construction, the Mishimoto Performance Radiator ensures the G16E-GTS can handle intense driving without sacrificing reliability or performance.

Comparison between the stock and Mishimoto coolant expansion tanks.

The Mishimoto Aluminum Coolant Expansion Tank for the 2023+ Toyota GR Corolla combines increased capacity and durability to meet the demands of spirited driving. Replacing the stock plastic tank, this upgrade delivers a 40% fill line capacity increase and a 50% overall tank capacity boost, along with improved resistance to wear from heat cycles. Its sleek, powder-coated finish in red or black not only enhances the engine bay's appearance but also ensures long-lasting performance. Designed with features like internal baffles for consistent coolant flow and optimal engine cooling, the tank is built to perform during daily commutes or track sessions.

 

This tank simplifies coolant system maintenance with its accessible bleed port, high-visibility sight glass, and stamped cold-fill line, ensuring ease of use for all drivers. Our engineers' thoughtful design ensures dependable performance, making it a valuable addition for GR Corolla owners seeking reliable cooling and peace of mind. With these benefits, the expansion tank not only maintains engine temperatures but also enhances the overall driving experience.

Performance Air Intake

The engine bay of the 2023 Toyota GR Corolla, featuring our Performance Air Intake.

Coming in the spring of 2025, the Mishimoto Performance Air Intake for the 2023+ Toyota GR Corolla is designed to enhance performance while maintaining compatibility with the vehicle’s sensitive PCV system. Through extensive testing, our engineers developed a hybrid intake system that optimizes airflow without triggering ECU error codes. This intake system delivers improved airflow and reduces intake air temperatures, resulting in a noticeable increase in horsepower and torque—up to 4hp and 4 ft-lbs at higher RPMs. The intake also offers a more aggressive sound during acceleration, making it a desirable upgrade for drivers seeking both performance and an enhanced driving experience.

 

In addition to its performance gains, the Mishimoto intake maintains the functionality of the stock PCV system and integrates seamlessly into the GR Corolla’s engine bay. It reduces airflow restriction by 10.5% at low loads and ensures better engine breathing under high-load conditions. The intake’s design also includes a high-flow conical filter and improved airbox components, which increase filtration efficiency and prevent excessive intake temperatures. The product has undergone rigorous road testing to ensure long-term reliability, making it a practical and high-performing upgrade for those looking to optimize their GR Corolla’s power without sacrificing engine safety.

The Mishimoto Racing Tow Hook installed on the 2023 Toyota GR Corolla.

While the stock tow hook gets the job done, it’s not the most visually appealing option to leave attached. This often means rummaging through your trunk, hoping it hasn’t been forgotten in the paddock. The Mishimoto Racing Tow Hook for the 2023+ Toyota GR Corolla combines sleek design with reliable functionality, eliminating the need to choose between practicality and style.

 

Crafted from durable 7075 aluminum and 304 stainless steel, this tow hook features a fold-down ring with a 2-inch inner diameter and a straight-pull strength rating of 8,000 pounds, meeting racing standards like SCCA and NASA. Powder-coated for lasting durability and available in five vibrant colors, it’s as stylish as it is functional. Additionally, we've included indicator arrow stickers for easy identification. Whether you’re building your GR Corolla for the street, track, or show, this tow hook is a must-have accessory.

All in all, the GR Corolla has been a welcome addition to our garage. Not only did we enjoy driving it, but we also took the task of improving upon an already fantastic vehicle as a welcome challenge. We've already seen some Mishimoto products on your GR Corollas on social media and on the road, and we look forward to seeing even more. Be sure to check out our complete line of products for the GR Corolla.

All photography featured in Vehicle Review section courtesy of Jeremy Wayman.