Segment:
Full-size Luxury Sedan
Competitors 1993:
BMW 7 Series, Lexus LS 400, Cadillac DeVille, Lincoln Town Car
Strengths Of Model:
Renowned Mercedes-Benz build quality, durable diesel engine, comfortable ride, sophisticated engineering
Vehicle Highlight 1:
The W126 chassis represented the pinnacle of Mercedes-Benz engineering and luxury for its era.
Manual Value Proposition:
Essential for owners to understand and properly maintain their investment, ensuring longevity and optimal performance.
Primary Focus:
Owner's operation, maintenance, and basic care
Secondary Focus:
Safety, instruments, controls, driving techniques, emergency procedures, appearance, and technical consumer information
Estimated Pages:
N/A (Digital Download)
Powertrain:
Engine (starting, operation, basic checks), Fuel System, Cooling System, Exhaust System
Chassis:
Brakes, Steering, Suspension, Wheels & Tires
Electrical:
Instruments and Controls, Lighting System, Battery, Fuses
Comfort Convenience:
Climate Control (Heater/Air Conditioner), Audio System, Power Accessories (Windows, Locks, Seats), Phone System (if applicable)
Safety Security:
Seats, Seat Belts, Supplemental Restraint System (SRS - Airbags), Child Seat Installation
Operation:
Pre-driving checks, starting and driving procedures, parking, proper operation of all vehicle systems
Maintenance:
Regular maintenance checks, fluid level checks, tire pressure checks, basic fluid top-offs, cleaning and care instructions
Emergency:
Starting with a dead battery, changing a flat tire, operating in adverse weather, basic troubleshooting for common warning lights
Depth:
Owner-level maintenance and operation; does not include detailed diagnostic or repair procedures typically found in a service manual
NHTSA Frontal Impact Rating:
Not available for this era
ABS:
Standard (Anti-lock Braking System)
Traction Control:
Not standard on 300SD
Airbags:
Driver's side Supplemental Restraint System (SRS) airbag
Seat Belts:
3-point inertia-reel seat belts front and rear
Rollover Protection:
Reinforced A-pillars and roof structure
Oil Change Interval:
Typically every 3,000-5,000 miles or 6 months, whichever comes first (refer to manual for specific recommendation)
Diesel Fuel Filter:
Recommended replacement every 15,000-20,000 miles or as indicated by service intervals
Air Filter Replacement:
Every 15,000-20,000 miles or as needed based on driving conditions
Transmission Fluid Service:
Typically every 30,000-50,000 miles
Engine Oil Type:
API CD or CE rated diesel engine oil, SAE 15W-40 recommended (check manual for ambient temperature specifics)
Coolant Type:
Mercedes-Benz Approved Antifreeze/Coolant (e.g., G48 blue)
Diesel Engine Common:
Glow plug system reliability, vacuum leaks, injector wear, timing chain stretch (though generally robust)
Electrical Common:
Wiring harness degradation (chrysler loom issues in some models), vacuum operated systems (central locking, cruise control), headlamp switch failure
Suspension Common:
Hydraulic self-leveling suspension (rear) leaks, sway bar bushings
Climate Control Common:
Blower motor resistor failure, evaporator leaks, vacuum actuator issues
Manufacturer Origin:
Germany
Brand Philosophy:
Engineering excellence, durability, safety, and luxury
W126 Generation Years:
1979-1991 (facelifted in 1985)
300Sd Introduction:
Introduced in 1981 in the US market as a response to fuel crises, replacing the 300SD of the W116 chassis. The W126 300SD was produced from 1981-1985, with the OM617 engine. The 1993 model year references a later model which would have been the W140 chassis S350 Turbodiesel, or potentially a misprint on the product information, as the W126 platform concluded its run in 1991. Assuming the product information is for a W126 chassis, the 300SD designation typically refers to earlier models. If this is indeed for a 1993 model, it would be the W140 S350 Turbodiesel, which used a different engine (OM603.97x).
Manufacturing Location:
Germany
W126 Production Total:
Approximately 890,000 units (all variants)
Industry Accolades:
The W126 chassis was widely praised for its engineering, safety, and luxury, earning numerous awards and critical acclaim during its production run.
Consumer Reports Reliability:
Generally considered reliable, especially the diesel powertrains, but susceptible to specific electrical and vacuum system issues common with age.
