For the 1985 Mercedes Benz 300SD with the 3.0L 5-cylinder engine (Code 617.951 H Diesel Turbo), the oil capacity is 8.5 quarts with a filter change. Recommended viscosities include 0W-30 or 0W-40 for all temperatures, and 5W-30, 5W-40, or 5W-50 for temperatures above -25°C. AMSOIL recommends AMSOIL 5W-40 FS 100% Synthetic European Motor Oil (EFMQT-EA) for high-performance European diesel protection.
What oil does a 1985 Mercedes Benz 300SD take?
The 1985 Mercedes Benz 300SD with the 617.951 H engine requires specific viscosities based on operating temperatures. The AMSOIL lookup oil grade is SEO41. For all temperature ranges, 0W-30 and 0W-40 are suitable. In warmer climates (above -20°C), 10W-40 is an option, while for temperatures above -25°C, 5W-30, 5W-40, and 5W-50 are recommended.
AMSOIL product recommendations
Based on the AMSOIL lookup data, here are the recommended products for your 1985 Mercedes Benz 300SD maintenance needs.
Engine Oil
| Product Name | Part Code |
|---|---|
| AMSOIL 5W-40 FS 100% Synthetic European Motor Oil | EFMQT-EA |
| AMSOIL 0W-40 FS 100% Synthetic European Motor Oil | EFOQT-EA |
Coolant & Antifreeze
| Product Name | Part Code |
|---|---|
| AMSOIL Passenger Car & Light Truck Antifreeze & Coolant | ANTPC1G-EA |
| AMSOIL Propylene Glycol Antifreeze and Engine Coolant | ANT1G-EA |
Transmission & Steering Fluids
| Product Name | Part Code |
|---|---|
| AMSOIL Signature Series Multi-Vehicle 100% Synthetic ATF | ATFPK-EA |
| AMSOIL OE Multi-Vehicle 100% Synthetic ATF | OTFQT-EA |
| AMSOIL 100% Synthetic Multi-Vehicle Power Steering Fluid | PSFCN-EA |
Brake Fluid
| Product Name | Part Code |
|---|---|
| AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid | BFLVCN-EA |
Diesel Fuel Additives & Maintenance
| Product Name | Part Code |
|---|---|
| MANN-FILTERS Fuel Filters | WK8173X-EA |
| AMSOIL Diesel Injector Clean Fuel Additive | adfpcn-ea |
| AMSOIL Diesel Cetane Boost Fuel Additive | acbcn-ea |
| AMSOIL Diesel Injector Clean + Cetane Boost Fuel Additive | adscn-ea |
| AMSOIL Engine Fogging Oil | fogsc-ea |
Engine Oil Specifications & Viscosity
| Viscosity Range | Temperature Condition |
|---|---|
| 0W-30, 0W-40 | All TEMPS |
| 10W-40 | Above -20°C |
| 5W-30, 5W-40, 5W-50 | Above -25°C |
Engine Oil Capacity & Torque
When performing an oil change, ensure you have the correct volume to prevent engine damage.
| Description | Value |
|---|---|
| Oil Capacity (with filter) | 8.5 quarts |
| Oil Drain Plug Torque | 20 ft/lbs |
Note: On models equipped with an oil cooler, additional oil may be required when the cooler is drained. Always allow 5 minutes after refilling or turning the engine off before checking the oil level.
How much transmission fluid does it take?
For vehicles equipped with the 4-speed 722.3 automatic transmission, the total fill capacity is 7.7 quarts, while the initial fill requirement is 6.6 quarts. The AMSOIL lookup note references the 722.3 specification for this application.
What are the coolant and brake fluid requirements?
The cooling system has a capacity of 13.2 quarts. For braking, the vehicle requires specific formulations; the AMSOIL lookup note references DOT 4 plus (specifically part numbers 0009895605090109, 0009895605110111, or 000989080701) or products approved on MB Sheet 331.0.
Diesel maintenance notes for this vehicle
- Oil Level Check: Always allow the engine to sit for 5 minutes after shutoff before checking levels to ensure an accurate reading.
- Coolant Mixing: If using AMSOIL Propylene Glycol Antifreeze, it is a concentrated formula and requires mixing with distilled or high-quality water.
- Filter Maintenance: Using premium media filters, such as MANN-FILTERS, can help reduce engine wear and maintain OEM service intervals.
- Storage Protection: For long periods of inactivity, using a fogging oil can protect internal engine components from rust.
Common diesel oil-related concerns and how AMSOIL products may help
| Concern | Why it matters | AMSOIL product | How it may help | Limitation |
|---|---|---|---|---|
| Injector Deposits | Dirty injectors reduce efficiency and power. | adfpcn-ea | Cleans injectors and restores power/torque. | Requires proper treat rate. |
| Low Cetane Levels | Affects combustion quality and startability. | acbcn-ea | Increases cetane up to 8 points for smoother idle. | Not a mechanical repair. |
| Turbo Lubrication | High heat and speed require robust oil. | EFMQT-EA | Provides exceptional engine protection for European diesels. | Must follow service intervals. |
Common maintenance concerns for this vehicle
Owners of vintage Mercedes diesel engines typically prioritize several key areas to ensure longevity:
- Cooling System Integrity: Maintaining proper coolant levels and quality is vital for managing high compression heat.
- Fuel System Cleanliness: Diesel injectors and pumps require clean fuel and lubrication to prevent wear.
- Turbocharger Lubrication: Ensuring the turbo remains well-lubricated is critical for preventing premature failure.
- Aging Components: Managing aging rubber components and vacuum systems common in this era of Mercedes vehicles.
Recall, TSB, and manufacturer communication notes
Official NHTSA recall research for the 1985 Mercedes Benz 300SD returned no recall records at this time. However, official recall/TSB research was not included in this draft yet; owners should always verify open recalls by VIN through an authorized dealer or the NHTSA website.
NHTSA complaint research also returned no complaint records for this specific year/make/model combination. Note that a lack of complaints does not prove a vehicle has no issues, as these are only reported incidents.
About this vehicle
The 1985 Mercedes-Benz 300SD is a notable representative of the brand’s diesel-powered luxury lineup. This model belongs to a lineage of high-end vehicles that includes the W126 series, which served as the second generation of the S-Class. The S-Class has historically been positioned as Mercedes-Benz’s flagship line, characterized by its ‘Sonderklasse’ (special class) designation and the introduction of advanced automotive technologies.
Specifically, the 300SD Turbodiesel was produced during a period (1981–1985) when Mercedes-Benz offered robust diesel variants within their premium sedan and coupé architectures. This vehicle features a 3.0L 5-cylinder diesel configuration with the engine code 617 951 H. Owners of this era of Mercedes-Benz diesel engines often focus on the longevity and mechanical durability inherent to these older compression-ignition powerplants.
Typical use cases for this vehicle include long-distance cruising and reliable daily transport, given its heritage as a flagship luxury model. From a maintenance perspective, owners typically prioritize cooling system integrity, fuel system cleanliness, and robust lubrication to manage the high compression ratios typical of these engines. Because technical specifications regarding exact output or specific fuel system tolerances can vary, it is recommended that owners consult dedicated service manuals for precise tuning and repair data.
Common questions about this vehicle’s diesel oil and maintenance
What is the oil capacity for my 1985 300SD?
The capacity is 8.5 quarts when replacing the filter. If your model has an oil cooler, you may need additional oil when draining the cooler.
Which AMSOIL oil is best for cold weather?
For temperatures below -25°C, the lookup suggests using viscosities like 0W-30 or 0W-40. The EFOQT-EA product is designed for the unique demands of European diesel vehicles.
How often should I change my coolant?
AMSOIL products like ANTPC1G-EA are engineered for protection up to 150,000 miles or 5 years, whichever comes first.
Can I use a multi-vehicle ATF in my Mercedes?
For the 4-speed 722.3 transmission, AMSOIL lists ATFPK-EA and OTFQT-EA as options.
How do I improve diesel fuel performance?
Additives like adfpcn-ea can help clean injectors, while acbcn-ea can increase cetane levels to improve startability and idle smoothness.
How do I check for open recalls?
While no NHTSA records were found for this model, you should always verify current recalls by checking your specific VIN through official Mercedes-Benz channels or the NHTSA website.
Disclaimer: All fluid capacities and viscosity grades must be confirmed via the owner’s manual or official Mercedes-Benz technical documentation to prevent engine damage.