[3][4][5] The first three generations of the WRX, sold until the 2015 model year, were based on standard Impreza platforms, and replaced the Subaru RX hatchback and saloon.

Several limited edition first-generation coupés were offered in the late 1990s and early 2000s which were never sold in the US and are highly sought after by Subaru enthusiasts.

The 9-2X was available in both a standard (Linear) and performance (Aero) package, the latter was essentially identical to the second-generation WRX wagon, mechanically.

The rear doors received a subtle reskin with an upwards kink and revised character line, but retained an otherwise identical shape.

Subaru had promised to completely move the WRX and STI off the Impreza chassis and body to create a standalone model,.

[22] The FA20's high compression ratio of 10.6:1 combined with its 68° intake and 54° exhaust cam phasing range allow it to produce excellent off-boost efficiency as well as a wide torque peak.

[citation needed] It also retains the hydraulic power steering system as opposed to using the standard WRX's new electric-assisted rack.

A new, larger 5.9-inch high-definition multi-function display replaced the older 4.3-inch unit allowing the driver to see vehicle functions more easily.

The 2019 WRX equipped with the optional Lineartronic CVT also came standard with the Subaru EyeSight driver assist technology.

All 1,000 of these Launch Edition models were painted in World Rally Blue Pearl along with gold-painted 18-inch BBS forged alloy wheels.

Up to 200 of the units could be equipped with the NBR Challenge Package, which features a carbon-fibre wing and a badge commemorating Subaru's class victory at the 2015 Nürburgring 24 Hours.

Blue stitching brings the color into the interior, and Subaru's seven-inch navigation system with a nine-speaker stereo is standard for this version.

Up to 350 units could be equipped with the NBR Challenge Package, which features a carbon fibre wing, front lip spoiler, and roof.

The WRX STI Diamond Edition rides on 19-inch lightweight and darkened aluminum Y-design alloy wheels.

[38] For the 2018 model year, Subaru of America introduced the WRX STI Type RA to celebrate the successful record attempt at becoming the fastest saloon around the Nürburgring.

The WRX STI Type RA featured 19" gold-colored forged wheels, carbon roof and spoiler, among other changes.

Black interior and exterior accents were added, with gunmetal finish 18" alloy wheels and Cool Grey Khaki paint also being the only wheel/color options.

Arai Motorsports will install the HKS parts while adding components of its own, including an RQA air filter and an in-house front chassis brace to help with frame rigidity.

A carbon fibre rear lip spoiler aids grip at insanely high speeds and serial-numbered Recaro bucket seats explicitly designed for the TC380 will hold the driver down inside.

[52] Again for the 2020 model year but only available to the Canadian market is the arrival of the winter warrior WRX STI Kanrai Edition.

Kanrai, which translates to "winter thunder," sports an exclusive Ceramic White exterior paint along with the aggressive characteristics found in the WRX STI.

Outfitted on this WRX STI is STI-tuned Bilstein performance suspension, lightweight 19" BBS forged alloy bronze-painted wheels paired with Michelin Pilot Sport Cup 2 tires, which deliver significant handling dynamics and grip.

It placed second to the 2015 Volkswagen GTI in separate comparison tests in the September 2014 issues of Car and Driver and Motor Trend.

[56][57] WRX STI models still suffer from past issues with the EJ257 engine, like piston ring and rod bearing failure under certain conditions.

In March 2022, Subaru announced they would not market the expected second-generation WRX STI high-performance model with an internal-combustion engine.

It features a new FA24F 2.4-litre turbocharged horizontally opposed four-cylinder boxer engine that produces 271 horsepower (202 kW; 275 PS) and 258 lb⋅ft (350 N⋅m; 36 kg⋅m) of torque.

Engine updates include a larger cylinder bore, an electronically controlled wastegate, and air bypass valves.

[70] 2025: The TR is replaced by tS model (Tuned by STI) features an upgraded Brembo brake system, Drive Mode Select, electronically controlled dampers, gold-painted calipers and the power output remain unchanged.

[84] The automotive press speculated the Viziv Performance concept shown at the Tokyo Motor Show in October 2017 would set the styling direction for the forthcoming second-generation WRX.

In 2016, former British rally champion Mark Higgins lapped the Isle of Man TT course with the VA WRX STI in 17 minutes, 35.139 seconds.