Factory build sheet

2021 Subaru Legacy Base

Build 4S3BWAA6-M · 2.5L 4cyl · All-wheel drive · Sedan

VIN positions 1 through 8 read 4S3BWAA6 and position 10 reads M. Those nine characters define this build. Position 9 and positions 11 through 17 differ on every car.

Every Legacy whose VIN starts 4S3BWAA6 and carries M in position 10 left the plant with the same engine, transmission, drivetrain and equipment listed below. We know of 61 of them.

  • Decoded Jul 7, 2026
  • 61 known VINs
  • 1 listed for sale now

Factory specification

As filed by Subaru with NHTSA for this build. Fields the filing does not record are left out entirely — a missing row means no recorded value, not a missing feature.

Engine

Displacement
2.5 L
Cylinders
4
Engine model
4-cylinder
Horsepower
182 hp
Fuel type
Gasoline

Drivetrain

Drive type
All-wheel drive

Body & chassis

Body class
Sedan/Saloon
NHTSA body type
PASSENGER CAR
Doors
4
Seats
5
Seat rows
2
Manufacturer
SUBARU OF AMERICA, INC

Weight rating

GVWR class
Class 1
GVWR
6,000 lb or less

Gross vehicle weight rating is the loaded ceiling set by the manufacturer, not the car's own weight.

Driver assistance, as built

  • Forward collision warning Standard
  • Crash imminent braking Standard
  • Lane departure warning Standard
  • Lane keeping assistance Standard
  • Adaptive cruise control Standard

Systems the filing does not record are not listed above. Check the window sticker of the exact car before you rely on any single feature.

The same build, other model years

Subaru used the VIN pattern 4S3BWAA6 for 2 model years. Nothing but the year changes between these pages, so the price gap between them is depreciation on an identical car.

How this VIN pattern is read

A 17-character VIN carries two kinds of information: what was built, and which one it is. This page is the first kind — the nine highlighted positions.

Positions Characters What they encode
1–3 4S3 SUBARU OF AMERICA, INC · World manufacturer identifier
4–8 BWAA6 Model, body style, engine and restraint system
9 × Check digit — computed per vehicle, not part of the build
10 M Model year — 2021
11 × Assembly plant
12–17 ×××××× Production sequence number, unique to each vehicle

NHTSA safety ratings

Crash-test results are published per model year and body style, so they cover the 2021 Subaru Legacy as a whole rather than this build alone.

Overall

★★★★★ 5 / 5

Frontal crash

★★★★★ 5 / 5

Side crash

★★★★★ 5 / 5

Rollover

★★★★★ 5 / 5

3 recall campaigns are recorded for the 2021 Legacy. Recalls are issued per VIN range — check the VIN of the car you are looking at, not the model.

61 vehicles carry this build

Every VIN we have decoded to 4S3BWAA6-M shares the specification above.

  • 61 Known VINs
  • 1 Listed for sale now

Neighboring configurations

Other factory configurations of the Legacy, each with its own build sheet. The set is fixed by the VIN patterns themselves, so it does not shuffle as prices or inventory move.

Keep going

Where this data comes from

Specification fields are decoded from the manufacturer's filings in the NHTSA vPIC database, keyed on VIN positions 1–8 and 10. We publish the filed values as they stand and leave out anything the filing does not record.

Vehicle counts come from the 61 VINs of this build we have seen in dealer inventory. They are a sample of the road population, not a production figure.