Tech guide · Brakes
Impreza brake disc sizes by model
Buying discs and pads for an Impreza is easy to get wrong: the same model name covers several different brake set-ups depending on year, market and spec. This guide lists the standard (factory) disc sizes for the turbo Imprezas most of us drive, from the classic GC8 to the last WRX STI. Sizes are diameter × thickness in millimetres.
Always confirm with your registration or chassis number before ordering. Japanese imports, special editions and cars that have already been upgraded often differ from the UK/Irish specification shown here.
At a glance
5×100 or 5×114.3
STIs changed wheel stud pattern in June 2004. Order discs by build date, not just “STI”.
326 mm Brembos
Every STI from 2001 to 2017 uses 326 mm front and 316 mm rear discs.
Measure first
Diameter, thickness and the number of caliper pistons tell you exactly what is fitted.
Classic Impreza (GC8 saloon / GF8 wagon), 1993–2000
| Model | Years (UK) | Front disc | Rear disc | Calipers | Min. thickness F / R |
|---|---|---|---|---|---|
| Impreza Turbo 2000 (UK) | 1994–1998 | 277 × 24 vented | 266 × 10 solid | Sliding front | 22 / 8.5 |
| Impreza Turbo 2000 (UK, MY99 facelift) | 1998–2000 | 294 × 24 vented | 266 × 18 vented | 4-pot front, 2-pot rear | 22 / 16 |
| Prodrive P1 | 2000–2001 | 294 × 24 vented | 266 × 18 vented | 4-pot front, 2-pot rear | 22 / 16 |
| 22B STI | 1998 | 294 × 24 vented | 286 or 290 × 10 solid | – | 22 / – |
| JDM WRX / STI imports | 1992–2000 | 277 or 294 × 24 vented | 266 solid/vented, or 290 on R180 cars | Varies by version | Varies |
Catalogues list the 4-pot front disc as 294 or 295 mm: it is the same part. JDM STI Type R and Type RA models from Version IV (late 1997) use the bigger R180 rear diff and a larger rear disc and handbrake drum. Check the rear set-up on any import before ordering.
New Age Impreza (GD saloon / GG wagon), 2000–2007
| Model | Years (UK) | Front disc | Rear disc | Calipers | Min. thickness F / R |
|---|---|---|---|---|---|
| WRX 2.0 (GDA / GGA) | 2000–2005 | 294 × 24 vented | 290 × 18 vented | 4-pot front, 2-pot rear | 22 / 16 |
| WRX 2.5 (GDG / GGG) | 2005–2007 | 294 × 24 vented | 290 × 18 vented | 4-pot front, 2-pot rear | 22 / 16 |
| WRX STI 2.0 (GDB), incl. WR1 | 2001–2005 | 326 × 30 vented | 316 × 20 vented | Brembo 4-pot front, 2-pot rear | 28 / 18 |
| WRX STI 2.5 (GDB / GDG) | 2005–2007 | 326 × 30 vented | 316 × 20 vented | Brembo 4-pot front, 2-pot rear | 28 / 18 |
Watch the wheel stud pattern on the STI. STIs up to mid-2004 use 5×100 hubs; from the 2005 model year (Revision E) they use 5×114.3. The disc size stays the same but the stud holes do not, so Brembo lists separate part numbers for cars built before and after 05/2004. Order by build date, not just “STI”.
Third generation (GR hatch / GV saloon), 2007–2014
| Model | Years (UK) | Front disc | Rear disc | Calipers | Min. thickness F / R |
|---|---|---|---|---|---|
| WRX 2.5 (GH / GR) | 2007–2011 | 294 × 24 vented | 286 × 10 solid | – | 22 / 8.5 |
| WRX STI 2.5 (GRB / GRF / GVB) | 2007–2014 | 326 × 30 vented | 316 × 20 vented | Brembo 4-pot front, 2-pot rear | 28 / 18 |
WRX STI (VA), 2014–2018
| Model | Years (UK) | Front disc | Rear disc | Calipers | Min. thickness F / R |
|---|---|---|---|---|---|
| WRX STI (VAB / VAF) | 2014–2017 | 326 × 30 vented | 316 × 20 vented | Brembo 4-pot front, 2-pot rear | 28 / 18 |
| WRX STI facelift (VAB / VAF) | 2017–2018 | 340 × 30 vented | 326 × 20 vented | Brembo 6-pot front, 2-pot rear | 28 / 18 |
Before you order
- Measure first: if you are not sure what is fitted, measure the disc diameter and thickness, and count the caliper pistons.
- Minimum thickness is the wear limit: replace the disc when it reaches this figure. It is usually stamped on the disc.
- Pads follow the caliper, not the model name: sliding, 4-pot and Brembo calipers all take different pad shapes.
- Upgrades: bigger discs need the matching calipers, carriers and often wheels to clear them. 16″ wheels will not clear the STI Brembos.
- NCT: worn discs, a weak handbrake and uneven braking side-to-side are common NCT fails, so check them before your test.
More guides
Impreza wheel fitment guide
Subaru Impreza service guide
Buying a used WRX or STI
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