Car Model History

Second generation · W126 · 1981–1991

1981Mercedes-Benz S-Class

The best-selling classic S-Class and a design icon. It reached US showrooms for 1981 (late-1980 launch). The first production car offered with a driver's airbag; later added a passenger airbag (1988). Also spawned the C126 coupe (SEC).

Second generation · W126

1981 Mercedes-Benz S-Class (W126) — sedan, front three-quarter view

Photo: “1981 Mercedes-Benz 280 SE (W 126) sedan (25041740475)” by Jeremy from Sydney, Australia / Wikimedia Commons, licensed under CC BY 2.0. Cropped to 16:9.

The 1981 model year

Overview

The W126 reached the United States for model year 1981 as the turbodiesel 300 SD and long-wheelbase gasoline 380 SEL. Mercedes-Benz's factory history describes the W126 as an aerodynamically optimized, weight-reduced flagship with light-alloy V8 engines and deformable plastic bumpers, and dates the airbag's entry into automobile production to 1981.

Specifications

Engines
  • 3.0-liter OM617 turbocharged diesel inline-five (125 hp)
  • 3.8-liter M116 fuel-injected V8 (155 hp U.S.)
Transmissions
4-speed automatic
Body styles
Four-door rear-wheel-drive luxury sedan, Four-door long-wheelbase rear-wheel-drive luxury sedan

Year over year

What changed

  • The U.S. range changed completely from the outgoing W116 to the two-model W126 roster.
  • The 300 SD and 380 SEL separated diesel standard-wheelbase and gasoline long-wheelbase roles.

Worth knowing

Notable

  • Contemporary U.S. testing identifies the same 300 SD and 380 SEL launch pairing recorded in the club's model-year table.

Living with it

Reliability & ownership notes

  • Confirm the chassis, engine number, market specification, and build date before ordering parts; U.S. model-year rosters do not describe gray-market or other-market W126 sedans.
  • Use the maintenance record scoped to the exact engine shown on this page; it must not be projected onto the diesel, coupe, or other W126 powertrains that the source does not cover.

Maintenance & service parts

Keep your 1981 S-Class 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 Mercedes-Benz S-Class. Start with the interval, confirm which engine or configuration you have, then use an exact ordering reference when one is verified.

Service topics
6
Scheduled topics
4
Applicability stated
6
Exact references
2

Before ordering Identify 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 filterView intervals, applicability and sources

    Engine oil and filter

    Sourced interval available

    Applies to: 1981 · OM617 turbocharged diesel inline-five · 300 SD · United States · Exact 1981 300 SD owner's-manual schedule. It is not claimed for the gasoline 380 SEL.

    Published interval: 7,500 mi / 12,000 km / 12 months · Required every 7,500 miles or at least once a year.

    Source: Mercedes-Benz — 1981 300 SD owner's manual maintenance system · owner's manual pages 58–59 — engine oil and filter change · checked

  • Maintenance serviceView intervals, applicability and sources

    Maintenance service

    Sourced interval available

    Applies to: 1981 · OM617 turbocharged diesel inline-five · 300 SD · United States · Exact 1981 300 SD owner's-manual schedule. It is not claimed for the gasoline 380 SEL.

    Published interval: 15,000 mi / 24,000 km / 24 months · Every 15,000 miles; for low-mileage operation, at least once every two years.

    Source: Mercedes-Benz — 1981 300 SD owner's manual maintenance system · owner's manual pages 58–59 — Mercedes-Benz Maintenance System · checked

  • Brake fluidView intervals, applicability and sources

    Brake fluid

    Sourced interval available

    Applies to: 1981 · OM617 turbocharged diesel inline-five · 300 SD · United States · Exact 1981 300 SD owner's-manual schedule. It is not claimed for the gasoline 380 SEL.

    Published interval: 12 months · Replace annually, preferably in spring.

    Source: Mercedes-Benz — 1981 300 SD owner's manual maintenance system · owner's manual page 59 — special maintenance measures · checked

  • Engine coolantView intervals, applicability and sources

    Engine coolant

    Sourced interval available

    Applies to: 1981 · OM617 turbocharged diesel inline-five · 300 SD · United States · Exact 1981 300 SD owner's-manual schedule. It is not claimed for the gasoline 380 SEL.

    Published interval: 36 months · Replace the water/anticorrosion-antifreeze mixture every three years.

    Source: Mercedes-Benz — 1981 300 SD owner's manual maintenance system · owner's manual page 59 — special maintenance measures · checked

  • Engine air filterView intervals, applicability and sources

    Engine air filter

    Exact reference available

    The part reference below is catalog fitment only; retain the separately sourced factory service interval where one is shown.

    Applies to: 1981

    380 SEL — 3.8-liter M116 fuel-injected V8 (155 hp U.S.)

    K&N E-2872

    Applies to: 1981 · 3.8-liter M116 fuel-injected V8 (155 hp U.S.) · 380 SEL · Exact 1981 380 SEL engine application. Confirm VIN and build date before ordering.

    Source: K&N Engineering — 2017 European Automotive Catalog, S-Class application tables (archived copy) · W126 S-Class table — 380 SEL, 1981 — E-2872 · checked

    Verified ordering references

  • Engine oil filterView intervals, applicability and sources

    Engine oil filter

    Exact reference available

    Use the exact engine, VIN, and build date to confirm the catalogued service part before ordering.

    Applies to: 1981

    300 SD — 3.0-liter OM617 turbocharged diesel inline-five (125 hp)

    MAHLE OX 78D

    Applies to: 1981 · 3.0-liter OM617 turbocharged diesel inline-five (125 hp) · 300 SD · Exact 1981 300 SD engine application. Confirm VIN and build date before ordering.

    Source: MAHLE Aftermarket — Mercedes-Benz passenger-car filter application catalog · 1981 Mercedes-Benz 300SD 3.0L L5 — OX 78D · 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. Mercedes-Benz Media — factory S-Class history and W126 design/safety chronology
  2. Mercedes-Benz Club of America — 1981–1991 W126 U.S.-market buyer's guide
  3. Car and Driver — February 1981 U.S. 300 SD and 380 SEL launch test

Other Second generation years

Explore the W126 generation →All Second generation · W126 years →

Complete, source-verified lineup

Find your exact 1981 S-Class

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 factory sedan, coupe, cabriolet, drivetrain, and powertrain roster represented by the cited exact-year or factory-archive evidence. Every version shown below has its own detail page.

Verified 2026-09-01 from Mercedes-Benz Club of America — 1981–1991 W126 U.S.-market buyer's guide, Car and Driver — February 1981 U.S. 300 SD and 380 SEL launch test.

2versions shown
Browse 2 documented records — use the filters above to narrow the list
Four-door rear-wheel-drive luxury sedan

Mercedes-Benz 300 SD Automatic

Body
Four-door rear-wheel-drive luxury sedan
Engine
3.0-liter OM617 turbocharged diesel inline-five (125 hp)
Gearbox
4-speed automatic
Built
Regular production
Open exact version
Four-door long-wheelbase rear-wheel-drive luxury sedan

Mercedes-Benz 380 SEL Automatic

Body
Four-door long-wheelbase rear-wheel-drive luxury sedan
Engine
3.8-liter M116 fuel-injected V8 (155 hp U.S.)
Gearbox
4-speed automatic
Built
Regular production
Open exact version

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