WRX and STI badges establish a factory claim that still needs evidence

What is the difference between a Subaru WRX and STI?

Subaru itself calls the WRX STI its performance flagship in official releases. That status does not allow a later STI checklist to be projected backward onto every classic Impreza.

What do WRX and STI stand for?

Capitalisation has varied between STi and STI over time. That typography can help date literature, but it should not be used as the only identity test on a replaced badge.

Subaru’s 2007 release states that the first WRX STI was based on the first Impreza WRX and developed by STI, then describes the third-generation car as a complete redesign with its own engine, chassis and mechanisms.

Later “STI Sport” or “STI Performance” accessory names do not automatically mean the historic full WRX STI model. Read the complete model designation and factory specification.

Why is there no single WRX versus STI parts list?

Subaru’s 2011 US release is a useful warning. It says the WRX adopted the same wide body as the WRX STI, with wider tread and tyres. Visual convergence did not erase the two model names.

Japanese-market cars can use two-litre engines and editions absent from the UK. US cars often use 2.5 litres in periods where Japanese cars do not. Output units and fuel also differ.

The nickname for the front is another independent field. Bugeye, blobeye and hawkeye describe visible second-generation revisions, not WRX or STI mechanical grade. The face comparison separates that question.

How do you verify whether an Impreza is a genuine STI?

Use a Subaru dealer, recognised register or specialist familiar with that market. A UK registration database may shorten an imported model name or carry an error.

Inspect stamped and labelled identity points for consistency and signs of repair. Valuable performance identities deserve specialist attention before purchase. Keep full VINs and document references out of public posts.

A registration year may be later than manufacture or import. Use build date and original model year rather than assigning hardware from the UK plate.

When evidence remains contradictory, call the car unverified. The cost of the wrong answer can exceed the inspection.

Which hardware can differ between WRX and STI?

DCCD, where fitted, is a driver-controllable centre differential system, not a universal feature on every WRX or every early-market STI. Do not add it to an advert from a switch photograph alone.

Mismatched final drives or hubs can create serious mechanical problems. A conversion needs part numbers and a specialist assessment of the whole system.

Does STI hardware turn a WRX into an STI?

Ask for donor identity, part numbers, installation invoices, calibration and insurer disclosure. Confirm that engine, gearbox, differential ratios, shafts, hubs, brakes and electronics are compatible.

A rolling-road figure does not establish model grade. Nor does a standard output figure prove the current engine remains standard.

Jonathan’s bugeye commission showed the reverse problem: its drawing was a standard STI, while 350 bhp and 4.3 seconds described a customer’s tuned engine. He chose the stock catalogue car, so those two modified figures were corrected while four matching STI figures stayed.

Which WRX or STI do the live Impreza prints represent?

The power is 261 bhp because the 265 rating is PS converted into the house bhp unit. The specification should not be copied onto a standard WRX merely because the face and paint match.

Build the bugeye STI print or build the blobeye STI print. Use custom work for a WRX-specific block.

What should a WRX or STI buyer check?

See the car genuinely cold and use a Subaru specialist. Listen and scan without assigning piston, bearing or differential diagnoses from one sound.

Tyres should match the exact AWD requirements in size, rolling circumference, load, speed rating and suitable wear. Mixed tyres can create symptoms and stress without proving an internal fault.

Inspect corrosion and repair quality underneath. Rally styling does not establish rally use, and an ordinary-looking car can have extensive track or accident history.

The blobeye buyer’s guide provides a practical checklist. Where its older title says WRX, the live signed car is now consistently STI after Jonathan’s later review.

Which Subaru sources support the badge distinction?

Read Subaru’s 2007 WRX STI release and 2011 WRX and STI comparison release. They were reviewed 9 August 2026.

This guide does not authenticate one car or provide a permanent parts list. Use the factory data for its VIN, year and original market.

Questions people actually ask

What is the main difference between a Subaru WRX and STI?

STI is the higher-performance factory derivative, typically with model-specific engine calibration and turbo, gearbox or differentials, brakes, suspension and equipment. The exact list varies by generation, year and market, so use dated Subaru technical data for the individual VIN.

Can you identify an STI from its wing or badge?

No. Wings, badges, grilles, seats, wheels and pink decals can be fitted later. Start with the VIN-linked Subaru build record and original market, then make the engine, transmission, differential controls, brakes, body and documented history agree.

Is a WRX modified to STI power an STI?

No. A modified WRX remains a WRX by factory identity unless official records establish otherwise. Describe the later engine, hardware and calibration accurately, with invoices and insurer disclosure, rather than changing the model name to match an output claim.

Are the live bugeye and blobeye prints WRX or STI?

Both live prints use Jonathan’s signed STI Type UK specification: 261 bhp, 343 Nm, 1,470 kg, 5.2 seconds to 60 mph and 148 mph. Their separate drawings represent the 2001 to 2002 bugeye and 2003 to 2005 blobeye faces.