SubaruWRX STI2021Overview/subaru/wrx-sti/2021/base/

2021 Subaru WRX STI

Factory specifications, fluid capacities, torque values, EPA fuel economy and the federal safety record for the 2021 WRX STI.

The 2021 Subaru WRX STI is identified in this reference by a 4.5-quart engine oil capacity and a specified 5W-30 viscosity, the concrete mechanical details available for the model year. Its reliability record registers 13 owner complaints and one recall, with Power Train and Engine issues constituting the top complaint category. Measured against the model’s 2008–2019 complaint history—where annual totals peaked at three in 2008 and bottomed at one in 2010—the 2021 model year sits well outside that prior range, carrying a substantially higher single-year complaint volume that signals a notable increase in documented owner concern.

Model year2021202020192018201720162015

Quick specs

Fluid capacities, tune-up values and fuel economy at a glance.

Engine oil capacity4.5 qtOEM · verified
Engine oil type5W-30OEM · verified

Fitment & sizes

Replacement part sizes and factory part numbers — battery, bulbs, filters and belts.

From the factory this vehicle uses a BCI 35 · 470 CCA battery. Each part links to every other vehicle that shares it, so a part you already stock may fit more of your fleet than you'd expect.

Battery groupBCI 35 · 470 CCAOEM · verified
Tire size245/35R19 89WOEM · verified
Wheel / rim8.5 inOEM · verified

Full specifications

Engine, drivetrain, dimensions and economy.

Dimensions & weight NHTSA vPIC

Overall length180.7 in
Overall width70.1 in
Overall height57.9 in
Wheelbase104.3 in
Curb weight3369 lb
Track (front / rear)60.2 / 60.6 in
Weight distribution (front / rear)60/40

Service quick specs OEM factory data

Capacities, torques and tune-up values from the factory service manual.

This engine holds 4.5 qt of 5W-30 engine oil, 75W-90 in the differential, DOT 3 brake fluid. Torque the oil drain plug to Use a new washer: 34.0 ft-lbs. The firing order is 1-3-2-4.

Lubricants & capacities

Brake FluidDOT 3
Clutch FluidDOT 3
Differential Gear Oil75W-90
Differential Gear Oil Capacity1.0 qt
Engine Oil5W-30 · Synthetic
Engine Oil Capacity4.5 qt
Manual Transmission FluidGL-4 · 75W-90
Manual Transmission Fluid Capacity4.3 qt

Engine torques

Connecting Rod (Large End) Bearings38.0 ft-lbs
Engine Flywheel Bolts55.0 ft-lbs
Exhaust Manifold to Cylinder Head Bolts29.5 ft-lbs
Engine Oil Pan Drain PlugUse a new washer: 34.0 ft-lbs
Oil Pump to Cylinder BLock Bolts/Studs56.0 inch lbs. ft-lbs

Chassis torques

Differential Fill PlugFinal Drive: Use new gasket: 44.0 ft-lbs
Differential drain PlugFinal Drive: Use a new gasket: 44.0 ft-lbs

Ignition

Cylinder Firing Order1-3-2-4
Curb Idle Speed (No Load)Checking Speed: 700 rpm
Curb Idle Speed Variance (No Load)100 rpm
Curb Idle Speed (Secondary Under Load)Speed-Up Speed: 750 rpm
Curb Idle Speed Variance (Secondary Under Load)100 rpm
Spark Plug ManufacturerSubaru
Spark Plug Gap0.019-0.023 in
Spark Plug Torque15.5 ft-lbs

Battery & A/C

Standard BCI Group Number35
Standard BCI Cranking Performance470 cca

Service checks

RPM43.5 @ Idle rpm

Multi-step torque procedures OEM · verified

Inspection Procedure (Lower) — tightening sequence 1 stages
1Inspect ball joint dust cover. Step 3: Replace ball joint if any looseness is detected during step 1. Step 4: Replace ball joint dust cover if any damage is noted during visual inspection of step 2.
Camshaft Bearing/Carrier Cap Bolts or Studs — tightening sequence 1 stages
189.0 inch lbs., Step 2: 15.089 in
Crankshaft Pulley and/or Damper Bolts — tightening sequence 1 stages
135.0 ft. lbs., Step 2: 55-65°35 ft. lbs
Cylinder Head — tightening sequence 1 stages
129.5 ft. lbs., Step 2: 51.0 ft. lbs., Step 3: Loosen Bolts 180° in reverse order 2 times. Step 4: 29.5 ft. lbs., Step 5: 51.0 ft. lbs., Step 6: Bolts 5, 4 & 1 360° in this specified order. Step 7: Bolts 1, 5 & 4: In this specified order 7.4 ft. lbs., Step 8: Bolts 1, 5 & 4: In this specified order 22.0 ft. lbs., Step 9: Bolts 1, 5 & 4: In this specified order 98-102°, Step 10: Bolt 1: 123-127°, Step 11: Bolt 5 then Bolt 4: 78-82°, Step 12: Loosen Bolts 3, 6 then 2 in this specified order: 360°, Step 13: Bolts 2, 6 & 3 in this order: 7.4 ft. lbs., Step 14: Bolts 2, 6 & 3 in this order: 22.0 ft. lbs., Step 15: Bolts 2, 6 & 3 in this order: 98-102°, Step 16: Bolt 1: 123-127°, Step 17: Bolt 6 then Bolt 3: 78-82°29.5 ft. lbs

Factory maintenance schedule OEM · verified

Normal service, condensed from the factory interval matrix.

Under the factory schedule, replace the engine oil and filter every 6,000 mi; spark plugs every 60,000 mi; coolant every 30,000 mi. The big-interval services (every 30,000 mi for coolant, and the transmission fluid) are the ones owners most often skip — on a lower-mileage example, assume the original fluids are still in it and check them first.

Every 6,000 miEngine Oil (drain & refill) · Engine Oil Filter (replace) · Tire & Wheel Assembly (rotate)
Every 12,000 miBrake Line (inspect) · Brake Linings (inspect) · Brake Rotor (inspect) · CV Joint Boot (inspect) · Cabin Air Filter (replace) · Clutch Assembly (inspect)
Every 30,000 miAccessory Drive Belt (inspect) · Brake Hydraulic System (drain, refill & bleed) · Clutch Hydraulic System (drain & refill) · Differential (inspect fluid level) · Engine Air Filter Element (replace) · Engine Coolant System (inspect fluid level)
Every 60,000 miSpark Plugs (replace) · Wheel Bearing (inspect)
Every 72,000 miFuel Filter (replace)
Every 96,000 miTiming Belt (replace)
At 137,500 miEngine Coolant System (drain, flush & refill)

Reliability & federal safety record

Owner-reported issues, recalls, investigations and service bulletins on record with NHTSA — an unfiltered look at what owners actually experience.

The 2021 Subaru WRX STI sits at the very end of the VA generation, which according to the federal record shows a clear shift after 2015: recalls dropped from two per year (2008–2014) to zero across 2015, 2018, and 2019, and complaint counts for those later VA years stayed modest at 1–3 per year against a backdrop of TSB activity ranging from 190 to 249. Compared with those late-VA predecessors, the 2021 model shows a wider distribution of complaint areas — Power Train/Engine (2), Power Train (2), Visibility/Wiper (2), and Electrical System (1) — with no crash or fire complaints recorded, indicating the issues are non-safety-critical and largely drivability or accessory related. The arc across the generation is one of declining recall activity and generally low complaint volume, with TSBs remaining consistently elevated, suggesting Subaru continues to issue technical service guidance even on vehicles without formal defects. 2021's complaint pattern — powertrain and visibility items rather than structural or safety defects — is consistent with the end-of-generation refinement rather than a new problem cluster. For a used-buy perspective, this is a defensible year within the VA run, though a pre-purchase inspection focused on the engine and drivetrain is warranted given the concentration of those complaints.

1
Open recalls
NHTSA campaigns
205
Service bulletins
Manufacturer communications
0
ODI investigations
Office of Defects Investigation
13
Owner complaints
0 involved a crash · 0 a fire
NHTSA crash-test rating federal NCAP · out of 5 stars
Overall★★★★★
Frontal★★★★★
Side★★★★★
Rollover★★★★★
Owner complaints by model year NHTSA · this generation & adjacent

Owner complaints filed with NHTSA, by component

All 13 complaints on record, top 8 components.

Power Train,Engine2
Power Train2
Visibility/Wiper2
Electrical System1
Seats1
Engine1
Engine,Fuel/Propulsion System1
Power Train,Electrical System,Engine1

Source: NHTSA Office of Defects Investigation complaint database.

Recalls NHTSA · verified

Showing 1 of 1 campaigns on record for this vehicle.

22V522000Exterior Lighting:Back Up Lights:SwitchReported 21/07/2022

Subaru of America, Inc. (Subaru) is recalling certain 2015-2021 WRX vehicles. The backup light switch may corrode and become inoperative, which can result in the backup lights not illuminating and the rearview camera… Remedy: Dealers will inspect and replace the backup light switch, as necessary, free of charge. Owner notification letters were mailed September 16, 2022. Owners may contact Subaru's…

Technical service bulletins NHTSA · verified

Showing 5 of 205 bulletins on record with NHTSA.

BulletinDateComponentSummary
02-193-24R2026-06-29EngineThis bulletin provides updated parts information and a service procedure to follow for…
09-74-21R2026-06-25EngineThis bulletin provides updated parts information and a service procedure to follow for…
SubaruNet Annoucement (E2026-06-11Unknown Or OtherThis announcement is requesting retailer staff to retain the EyeSight protective hood…
01-167-08R2026-05-18Unknown Or OtherThis bulletin contains additional information for recommended materials listed in the…
02-193-24R2026-05-13EngineThis bulletin provides updated parts information and a service procedure to follow for…

Common OBD-II trouble codes

The most common OBD-II codes for this vehicle's emissions system. These are standardized SAE J2012 definitions, not vehicle-specific fault reports.

P0420
Catalyst system efficiency below threshold — Bank 1
P0300
Random / multiple cylinder misfire detected
P0171
System too lean — Bank 1
P0455
Evaporative emission system leak detected — large leak
P0128
Coolant thermostat below regulating temperature
P0442
Evaporative emission system leak detected — small leak

VIN tools

Decode factory build data for a specific vehicle by VIN.

VIN
Decode a VIN to confirm the transmission and build data for a specific WRX STI. OEM
Build data
Plant, GVWR class, engine and body data for any 17-character VIN.
Recalls
Check open recall campaigns against a specific vehicle by VIN.

Vehicles with shared specs

Find every vehicle that shares this one's battery, bulbs, oil capacity, platform or parts.

Reference guides

Cross-vehicle references for the kinds of data on this page.

Frequently asked

How much oil does the 2021 WRX STI take?

4.5 qt of 5W-30 Synthetic, per the factory manual.

Does the 2021 WRX STI have open recalls?

NHTSA lists 1 recall campaign(s) for this model year. Check your specific vehicle by VIN.