Canvas Top Menu

Evolution. Wait, that’s not right: A Decade of STI


The dawn of the new millennium has been somewhat kind to Subaru in terms of brand imaging. While the other manufacturers upped and left the high performance segment to focus on being ‘eco friendly’, it seemed as if there wasn’t any decent mass production performance car to speak of; save of course for the WRX STI, the Lancer Evolution, and a couple others. Capitalizing on their rally prowess, matched with every-day drivability, the STI was indeed an enticing prospect for the guy who wants a little — okay, maybe a lot — more out of his daily commuter.


With the image of a Rally Blue car on Gold Wheels airborne over a crest, many have set out to build their WRX STIs into machines that would emulate the image burned into their heads. Given the context of being a road-legal car, many of these cars would end up holding their own on the streets and circuits against cars double or triple their value, all while picking up the kids and the groceries.


That said, the aftermarket has lent itself very well to these cars. And with the trio of STIs we have here, we get a glimpse at how different (or similar) their tuning menus can be despite their aesthetic changes.

When speaking of tuning, we’d have to start with discussing the motor. Above you’ll find the boxer motors sitting underneath the 2007 STI as compared to the 2015 STI. The EJ257 2.5L boxer has always been a staple for STIs the world over, and while it has its fair share of issues, is still considered a potent platform to build power on, given a proper build process.


The 2015 model actually has people wondering why the STI hasn’t swapped over to the newer FA series motor found in the 2015 WRX, though from the looks of it, it appears Subaru went with the ‘tried and tested’ method for the newer STI’s motor. It would’ve been nice to see a new generation boxer in the new STI, but perhaps that’ll have to be saved for the next generation.


The 2012 GVF STI we had on the other hand has a bigger dose of parts applied to its motor. Being a proper example of what could be done to pretty much any ST. A good number of these parts could easily fit the previous or the next generation of EJ25s*. Subaru parts generally tend to be plug and play, save for parts that involve contouring to the body or specific sensors (i.e. Downpipes, O2 sensors, etc.)

*Still, it’s best to check – and double check – part numbers when ordering parts for your car.

The interior is where we’ll actually find the STI’s maturity more evident than anywhere else. You’ll notice that the 2007 GDB STI still somewhat harks back to Subaru’s spartan days with the mundane interior and a sad attempt at being ‘lively’ (read: blue trim on the seats). Back then, though, the interior — nor the exterior for that matter — didn’t matter to the guys at Fuji Heavy Industries; all that mattered was that the car drove well. All you had to concentrate on was the road and that glaring red gauge cluster in front of you, and that was all that mattered.

The latter years of the STI, however, saw an overhaul to the car’s interior. With increasing demand and a substantially growing market, the STI had to keep up with the rest of the competition by making the interior rather habitable. Nowadays you’ll find that Subarus have much improved their interior game with liberal use of leather trim and baseball stitches.

One thing that would be missed from the GDB STI would be the OEM gauge pod that changes the dashboard tray into a shroud where your aftermarket gauges could snuggle into. And while the 2008-2012 STIs would have to do without those, the 2015 has parameters like boost, water temp, and oil temp built into its in-dash display, thus eliminating the need for gauges altogether for the average Joe. Way for the factory to meet the needs of their clients, I suppose!


As far as wheels are concerned, the STIs, across all generations, are spoiled for choice. With a 5 x 114.3 bolt pattern (unlike the standard 5 x 100 fare of other Subarus) and fairly conservative offsets, there are plenty of options out in the market for these vehicles. The cars we have here are sporting model-specific offerings from Prodrive and Rays Engineering to ensure that the wheels fill the rather large wells of the STIs nicely. As for braking solutions, thankfully STIs come with 4-pot front and 2-pot Brembos as standard. Normally, with an addition of stainless lines, better brake pads, and perhaps slotted rotors, these systems would be more than enough. If you seek even more grab from the middle pedal however, Big Brake Kits for these vehicles are plenty, as demonstrated by the Alcon BBK peeking beneath the 2015 STI’s ZE40’s for example.

As the GDB Hawkeye is almost a decade old, it’s safe to say that its front fascia has aged quite well and would serve to remind people of where Subaru came from; Its iconic 3-piece wingspan-inspired grill supposedly serving as a reminder of Fuji Heavy Industries’ aircraft building roots. Again, with the need to expand with the growing market, the 2015 STI has somewhat deviated from Subaru’s old quirky look, instead conforming to the norm with more curves and fancy creature comforts here and there. Heck, the new STI has been criticized for looking somewhat like its quintessential rival’s last iteration, the Evo X. I suppose this is just a sign of the times, but it doesn’t really take much away from the sheer performance these cars have on offer.


Out back, the STI’s signature wing has also seen its fair share of changes. What started out as a boxy ornament on top of the trunk on the GDB became an exercise in sharper angles and smaller wing bases on the edge of the trunks of the GVF and VA STIs.


After a good two decades of providing rally-derived performance for the streets, Subaru’s STI has surely made it onto the mainstream as a ‘jack of all trades’ type of car. In a time when people sought speed with no-frills practicality, the STI was there to provide performance in spades all the way. Perhaps we’ll see even more drastic changes to it in the years to come, but for now, it appears that people are more than happy to keep toying with the generations from the new millenium.


This is dedicated to J.R.

Photos by Jet Rabe


2007 Subaru Impreza WRX STI

Engine and Driveline

298whp/290lb/ft tq.

  • HKS SSQV 2 Blow Off Valve
  • AEM Methanol Injection Kit
  • Turbosmart Manual Boost Controller
  • HKS Muffler
  • Speedlab 3” midpipe
  • Drop in air filter

Brakes, Wheels, and Suspension

  • Prodrive GC-05 18’s
  • Tein Super Street Coilovers
  • Full Set of Cusco Power Braces


  • Cusco 7pt. Roll Cage
  • Defi BF Boost/Water Temp/Oil Pres gauges w/OEM Gauge Pod
  • HKS Turbo Timer


  • HC Racing Vented Carbon Hood
  • HC Racing Carbon Chin


2012 Subaru Impreza WRX STI

Engine and Driveline

297whp & 295lb/ft. torque

  • HKS Intake
  • Process West Top Mount Intercooler
  • Tomei Expreme Equal Length Headers
  • Okada Projects Plasma Direct Coil
  • Grimmspeed Electronic Boost Control Solenoid
  • Deatschwerks DW65C Fuel Pump
  • AVO Turbo Inlet Hose
  • Turbo Heat Shield
  • Perrin Radiator/Boost Controller Cover
  • Invidia 3” Catless Downpipe with Divorced wastegate
  • Blitz Nur Spec 3” Catback Exhaust

Brakes, Wheels, and Suspension

  • Tein Monoflex Coilovers
  • Tein Electronic Damping Force Controller (EDFC)
  • HardRace Rear Lower Control Arm
  • HardRace Rear Toe Control
  • Volk Rays Engineering TE37 Tokyo Time Attack 19×8.5
  • Bridgestone RE11 245/35/R19


  • Pioneer AVH-P8450BT Head Unit
  • Defi Advance Boost/Oil Temp/Oil Press 60mm gauges
  • Defi Advance Controller
  • Blitz Throttle Controller
  • HKS Turbo Timer
  • DAMD D-Cut Steering Wheel
  • STI Shift Knob
  • 3M Black Chrome Tint BC10/BC20
  • 3M Matting


  • Cusco Short Antenna
  • STI Front Lip
  • STI Side Skirts


2015 Subaru Impreza WRX STI

Engine and Driveline

– Stock

Brakes, Wheels, and Suspension

  • Alcon Big Brake Kit 365mm F/343mm R
  • Volk Rays Engineering ZE40 19×8.5
  • Nitto NT555 245/35/R19
  • Tein Flex-Z Coilovers
  • Cusco Front Upper Strut Bar


  • ARC Shift Knob
  • Pioneer 8750 Head Unit


  • STI Body kit


, , , ,