Car Model History

First generation · E21 · 1977–1983

1981BMW 3 Series

The original 3 Series — a two-door sport sedan that replaced the 02 Series (the 2002). US cars arrived for 1977; the E21 established the compact rear-drive BMW formula the line still follows.

First generation · E21

1981 BMW 3 Series (E21, first generation) — 320, front three-quarter view

Photo: “BMW 3-Series (E21) 320 (1981)” by Charles from Port Chester, New York / Wikimedia Commons, licensed under CC BY 2.0. Cropped to 16:9.

Quick facts

Engines
1offered1.8L fuel-injected M10 inline-four
Top output
101hp1.8L fuel-injected M10 inline-four

Body stylesTwo-door sedan

Start here

What do you need to know?

This page covers the whole 1981 BMW 3 Series model year. Choose your task first; exact trims and engines are separated where the factory offered different versions.

Complete, source-verified lineup

Find your exact 1981 3 Series

Start with a family, body style, or engine. Every card opens the facts and maintenance information for that factory version.

2factory configurations
Verified complete for the U.S.-marketHow this lineup was verified

We checked this U.S.-market lineup against period sources for BMW's complete 1981 U.S. E21 roster: the 1.8-liter 320i and documented 320iS equipment configuration. Every version shown below has its own detail page.

Verified 2026-09-01 from BMW of North America — first 3 Series U.S. history and specifications, Car and Driver — November 1980 road test and specifications for the 1981 BMW 320iS, BMW of North America — 320iS heritage in the 2011 model-year update.

2versions shown
Two-door sedan

BMW 320i

Body
Two-door sedan
Engine
1.8L fuel-injected M10 inline-four (101 hp / 100 lb-ft)
Gearbox
5-speed manual or 3-speed automatic
Built
Regular production
Open exact version
Two-door sport sedan

BMW 320iS

Body
Two-door sport sedan
Engine
1.8L fuel-injected M10 inline-four (101 hp / 100 lb-ft)
Gearbox
5-speed manual
Built
Regular production
Open exact version

The 1981 model year

Overview

BMW's 1981 U.S. catalog centered on the two-door 320i with a 101-hp, 100-lb-ft 1.8-liter fuel-injected M10. The 320iS paired that same engine with a five-speed manual and a substantial S equipment package rather than adding horsepower.

Specifications

Engines
  • 1.8L fuel-injected M10 inline-four101 hp
Body styles
Two-door sedan

Year over year

What changed

  • The 320iS enthusiast configuration was documented with a five-speed Getrag manual, limited-slip differential, sport suspension, and Recaro seats.
  • The S designation changed equipment and chassis specification, not engine output.

Worth knowing

Notable

  • A November 1980 period test records the 1981 320iS at 101 hp, 100 lb-ft, and a five-speed manual.
  • BMW's original 1981 full-line brochure record identifies the 320i alongside the company's larger U.S. models.

Living with it

Reliability & ownership notes

  • Verify the 1.8-liter M10 and five-speed/manual-versus-automatic configuration before ordering drivetrain parts.
  • On a claimed 320iS, authenticate the period Recaro seats, limited-slip differential, suspension, air dam, wheels, and related S equipment.

Maintenance & service parts

Keep your 1981 3 Series on the road

Start with the service interval, then match the engine or exact version you own. Order links appear only when a catalog-backed part number is available, and every listing still needs a fitment check.

Service desk

What this car needs & when

Use this as a service-planning checklist for 1981 BMW 3 Series. Start with the interval, confirm which engine or configuration you have, then use an exact ordering reference when one is verified.

Service topics
12
Factory intervals
8
Fitment-scoped
12
Exact references
5

Before orderingIdentify your engine, options and build date.Part numbers and sizes can change within one model year. Shopping links appear only for catalog-backed references; still verify the listing against your vehicle before ordering.

  • Engine oil and filter

    Sourced interval available

    Applies to: 1981 · M10 1.8L fuel-injected inline-four · 320i (E21) · United States · Exact 1981 US 320i factory handbook; other-market E21 engines and configurations are not claimed.

    Published interval: 7,500 mi / 12,000 km · BMW Oil Service interval.

    Source: BMW — 1981 320i Owner's Handbook (HOK 516 / E21 80 01 US, factory U.S. edition; preserved by ProjectE21) · Owner's Handbook p. 102 — engine-oil and oil-filter rows · checked

  • BMW Inspection

    Sourced interval available

    Applies to: 1981 · M10 1.8L fuel-injected inline-four · 320i (E21) · United States · Exact 1981 US 320i factory handbook; other-market E21 engines and configurations are not claimed.

    Published interval: 15,000 mi / 24,000 km · After the initial 600-mile inspection, repeat the published BMW Inspection at this interval.

    Source: BMW — 1981 320i Owner's Handbook (HOK 516 / E21 80 01 US, factory U.S. edition; preserved by ProjectE21) · Owner's Handbook pp. 102–103 — service-instruction-plan column headings · checked

  • Manual-gearbox oil

    Sourced interval available

    Applies to: 1981 · M10 1.8L fuel-injected inline-four · manual · 320i (E21) · United States · Exact 1981 US 320i factory handbook; other-market E21 engines and configurations are not claimed.

    Published interval: 30,000 mi / 48,000 km · Replacement interval after the initial 600-mile change.

    Source: BMW — 1981 320i Owner's Handbook (HOK 516 / E21 80 01 US, factory U.S. edition; preserved by ProjectE21) · Owner's Handbook p. 102 — manual-gearbox oil row and footnote 1 · checked

    Automatic-transmission oil

    Applies to: 1981 · M10 1.8L fuel-injected inline-four · automatic · 320i (E21) · United States · Exact 1981 US 320i factory handbook; other-market E21 engines and configurations are not claimed.

    Published interval: 30,000 mi / 48,000 km · Replacement interval.

    Source: BMW — 1981 320i Owner's Handbook (HOK 516 / E21 80 01 US, factory U.S. edition; preserved by ProjectE21) · Owner's Handbook p. 102 — automatic-transmission oil row and footnote 1 · checked

  • Final-drive oil

    Sourced interval available

    Applies to: 1981 · M10 1.8L fuel-injected inline-four · 320i (E21) · United States · Exact 1981 US 320i factory handbook; other-market E21 engines and configurations are not claimed.

    Published interval: 30,000 mi / 48,000 km · Replacement interval after the initial 600-mile change.

    Source: BMW — 1981 320i Owner's Handbook (HOK 516 / E21 80 01 US, factory U.S. edition; preserved by ProjectE21) · Owner's Handbook p. 102 — final-drive oil row and footnote 1 · checked

  • Engine coolant

    Sourced interval available

    Applies to: 1981 · M10 1.8L fuel-injected inline-four · 320i (E21) · United States · Exact 1981 US 320i factory handbook; other-market E21 engines and configurations are not claimed.

    Published interval: 24 months · Renew with an ethylene-glycol coolant compatible with the aluminum engine and radiator.

    Source: BMW — 1981 320i Owner's Handbook (HOK 516 / E21 80 01 US, factory U.S. edition; preserved by ProjectE21) · Owner's Handbook p. 103 — radiator row · checked

  • Brake and clutch hydraulic fluid

    Sourced interval available

    Applies to: 1981 · M10 1.8L fuel-injected inline-four · 320i (E21) · United States · Exact 1981 US 320i factory handbook; other-market E21 engines and configurations are not claimed.

    Published interval: 12 months · Renew the brake-system fluid once a year; use DOT brake fluid.

    Source: BMW — 1981 320i Owner's Handbook (HOK 516 / E21 80 01 US, factory U.S. edition; preserved by ProjectE21) · Owner's Handbook p. 103 — brake/clutch row · checked

  • Main fuel filter

    Sourced interval available

    Applies to: 1981 · M10 1.8L fuel-injected inline-four · 320i (E21) · United States · Exact 1981 US 320i factory handbook; other-market E21 engines and configurations are not claimed.

    Published interval: 30,000 mi / 48,000 km · Replacement interval; clean the pre-mesh filter screen in the fuel tank.

    Source: BMW — 1981 320i Owner's Handbook (HOK 516 / E21 80 01 US, factory U.S. edition; preserved by ProjectE21) · Owner's Handbook p. 103 — fuel-supply rows and footnote 1 · checked

  • Engine air-filter element

    Exact reference available

    Applies to: 1981 · M10 1.8L fuel-injected inline-four · 320i (E21) · United States · Exact 1981 US 320i factory handbook; other-market E21 engines and configurations are not claimed.

    Published interval: 30,000 mi / 48,000 km · Renewal interval.

    Source: BMW — 1981 320i Owner's Handbook (HOK 516 / E21 80 01 US, factory U.S. edition; preserved by ProjectE21) · Owner's Handbook p. 103 — air-filter row and footnote 1 · checked

    Verified ordering references

    • Original equipmentBMW 13721278138

      Qty. 1 · Engine air-filter element; current replacement for 13 72 1 261 012 and 13 72 1 271 254 · current

      The 1981-selected BMW catalog lists 13 72 1 278 138 for the E21 320i and identifies the two earlier numbers it replaces; confirm VIN and installed airbox before ordering.

      Catalog: BMW electronic parts catalog — 1981 320i (E21) genuine air-filter listing · Genuine 1981 BMW 320i Air Filter — part 13721278138 and supersession list · checked

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  • Front windshield-wiper blade set

    Exact reference available

    BMW 61 61 9 069 195

    Applies to: 1981 · M10 1.8L fuel-injected inline-four · 320i (E21) · United States · Exact 1981 catalog fitment only; this parts record does not establish a replacement interval. Confirm the VIN and installed wiper arms before ordering.

    Source: BMWPartsDeal — exact-year 1981 BMW 320i front-wiper catalog listing · Genuine 1981 BMW 320i Wiper Blade — Front Windshield Wiper Blade Set 61619069195 and supersession list · checked

    Verified ordering references

    • Original equipmentBMW 61619069195

      Qty. 1 · Front · Front windshield-wiper blade set; current replacement for 61 61 1 362 189, 61 61 9 061 906, 61 61 1 365 883, and 61 61 1 365 991 · current

      The 1981-selected catalog lists this complete front set for the E21 320i. Confirm the VIN and installed wiper arms before ordering, especially if the car has been modified.

      Catalog: BMWPartsDeal — exact-year 1981 BMW 320i front-wiper catalog listing · Genuine 1981 BMW 320i Wiper Blade — Front Windshield Wiper Blade Set 61619069195 and supersession list · checked

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  • Air-conditioning compressor belt

    Exact reference available

    BMW 64 55 1 722 991

    Applies to: 1981 · M10 1.8L fuel-injected inline-four · 320i (E21) with air conditioning · United States · Exact 1981 catalog fitment for an air-conditioning-equipped car only; this record does not establish a replacement interval or the separate alternator/water-pump belt. Confirm the VIN, installed compressor drive, and belt routing before ordering.

    Source: BMWPartsDeal — exact-year 1981 BMW 320i drive-belt catalog listing · Genuine 1981 BMW 320i Drive Belt — AC Belt 64551722991 and supersession list · checked

    Verified ordering references

    • Original equipmentBMW 64551722991

      Qty. 1 · Air-conditioning compressor drive · A/C belt; current replacement for 64 52 1 469 234, 64 55 1 469 267, 64 55 1 717 230, 64 55 1 722 990, and 64 52 1 276 096 · current

      Applies only when the car has the cataloged air-conditioning compressor drive; it is not the separate alternator/water-pump belt.

      Catalog: BMWPartsDeal — exact-year 1981 BMW 320i drive-belt catalog listing · Genuine 1981 BMW 320i Drive Belt — AC Belt 64551722991 and supersession list · checked

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  • Front brake pads and rear brake shoes

    Exact reference available

    BMW 34 11 1 159 249 front; 34 21 1 160 165 rear

    Applies to: 1981 · M10 1.8L fuel-injected inline-four · 320i (E21) · United States · Exact 1981 catalog fitment only; replace friction material according to measured wear and hardware condition. Confirm the VIN and installed front calipers/rear drums before ordering.

    Source: BMWPartsDeal — exact-year 1981 BMW 320i brake-pad and shoe catalog listing · Genuine 1981 BMW 320i Brake Pads — Front Brake Pad Set 34111159249 and rear Brake Shoe Lining Repair Kit 34211160165 · checked

    Verified ordering references

    • Original equipmentBMW 34111159249

      Qty. 1 · Front axle · Asbestos-free front brake-pad set; replaces 34 11 1 150 527, 34 11 1 150 523, 34 11 1 118 517, and 34 11 1 150 524 · current

      One cataloged front-axle set; confirm the installed calipers and inspect rotors and hardware before ordering.

      Catalog: BMWPartsDeal — exact-year 1981 BMW 320i brake-pad and shoe catalog listing · Genuine 1981 BMW 320i Brake Pads — Front Brake Pad Set 34111159249 and supersession list · checked

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    • Original equipmentBMW 34211160165

      Qty. 1 · Rear axle · Asbestos-free rear brake-shoe lining repair kit; replaces 34 21 1 121 586, 34 21 1 108 430, and 34 21 1 111 484 · current

      One cataloged rear-axle shoe kit; confirm the installed drums and inspect cylinders and hardware before ordering.

      Catalog: BMWPartsDeal — exact-year 1981 BMW 320i brake-pad and shoe catalog listing · Genuine 1981 BMW 320i Brake Pads — rear Brake Shoe Lining Repair Kit 34211160165 and supersession list · checked

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  • Engine oil filter — catalog fitment

    Exact reference available

    Applies to: 1981 · United States

    1.8L fuel-injected M10 inline-four (101 hp / 100 lb-ft) — K&N HP-1002

    K&N HP-1002

    Manufacturer-catalog replacement-part fitment only; it does not establish a BMW service interval. Confirm the VIN, production date, engine, and installed filter dimensions before ordering.

    Applies to: 1981 · 1.8L fuel-injected M10 inline-four (101 hp / 100 lb-ft) · 320i · United States · Exact model-year and engine-family catalog scope; verify VIN and production date before ordering.

    Source: K&N — BMW 320i replacement oil-filter catalog · 1981 BMW 320i 1.8L/2.0L gasoline — HP-1002 · checked

    Verified ordering references

    1.8L fuel-injected M10 inline-four (101 hp / 100 lb-ft) — K&N HP-1002

    K&N HP-1002

    Manufacturer-catalog replacement-part fitment only; it does not establish a BMW service interval. Confirm the VIN, production date, engine, and installed filter dimensions before ordering.

    Applies to: 1981 · 1.8L fuel-injected M10 inline-four (101 hp / 100 lb-ft) · 320iS · United States · Exact model-year and engine-family catalog scope; verify VIN and production date before ordering.

    Source: K&N — BMW 320i replacement oil-filter catalog · 1981 BMW 320i 1.8L/2.0L gasoline — HP-1002 · checked

    Verified ordering references

Collect

Bring this model year home

Find a scale model using the exact year, make, and model—not a generic generation search.

Sources

  1. BMW of North America — original 1981 full-line sales brochure record
  2. Car and Driver — November 1980 road test and specifications for the 1981 BMW 320iS
  3. BMW of North America — 320iS heritage in the 2011 model-year update

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