Note: Individual characteristics are also given in the text of the Chapter and, if their implementation is mandatory, are highlighted in bold.
Fuel grades
Petrol models
Unleaded gasoline not worse than AI95/A85. Short-term use of unleaded gasoline not worse than AI91/A82.5 is permitted (the engine power output decreases slightly, fuel consumption increases).
Attention! The use of fuel additives may result in premature wear and damage to internal engine components!
Diesel models
Summer and winter diesel fuel
Attention! Do not use marine, boiler or similar diesel fuels!
Note: When using diesel fuel with increased (more than 0.5%) sulfur content, change the engine oil every 7,500 km.
Winter fuel ensures normal engine performance at temperatures down to -20°C.
Thanks to fuel preheating when the interior heating system is switched on, trouble-free engine operation is guaranteed at outside temperatures down to -25°C.
Attention! Do not mix gasoline with diesel fuel!
When using summer diesel fuel, as well as at outside temperatures below -15°C, a certain amount of flow improver or kerosene, depending on the outside temperature, should be added to the fuel.
Composition of the mixture
| Outside air temperature°C | -15 to –23 | -23 to -30 |
| Summer diesel fuel | 80% | 50% |
| Kerosene | 20% | 50% |
| Outside air temperature°C | -25 to –30 | -30 to -35 |
| Winter diesel fuel | 80% | 50% |
| Kerosene | 20% | 50% |
Flow improvers can also be used in combination with kerosene.
A certificate of approved fluidity improving agents can be obtained at any Mercedes-Benz service station.
The proportion of additive content, taking into account the outside air temperature, should be minimal.
The proportion of kerosene in the mixture should not exceed 50%.
The additive must be added to the fuel during refueling before it thickens and paraffin is released. Malfunctions due to paraffin release can only be eliminated by heating the entire fuel system.
Mix diesel fuel with kerosene only in the fuel tank - first pour kerosene into the tank, then add diesel fuel. Finally, let the engine run for some time to distribute the mixture throughout the entire fuel system.
Warning! Kerosene additives lower the flash point of diesel fuel, which increases the fire hazard of the mixture! Follow the relevant safety regulations!
Fuel tank capacity, l
| Models without ski bag | |
| Full capacity approx | 88 |
| Including fuel reserve of about | 11 |
| Models with ski cover | |
| Full capacity approx | 78 |
| Including fuel reserve of about | 10 |
Petrol engine injection system
| System type | Electronic microprocessor distributed injection system. Intake manifold with variable geometry. |
| S280 S320 | Bosch HFM |
| S420, S500, S600 | Bosch LH or ME |
Diesel engine injection system
| Type | Bosch injection pump, PES 6M RS 181, No.0 400 076 956 with dual chain drive from crankshaft sprocket |
| Injection timing | It is set using a control pin, the engine must be at TDC |
| Regulator | № 0 400 076 956 |
| Bosch injectors, | № 0 432 217 266 |
| System pressure, bar | |
| At the outlet of the fuel pump (S500, S600) | 5.3-5.5 |
| With vacuum off | 3.7-4.2 |
| With vacuum connected | 3.2-3.6 |
| On open injectors (TDI) | |
| New/used | 115-125/100 |
| Coolant temperature sensor resistance, Ohm (at temperature) | |
| S280, S320 | 309-341 (80°) |
| S420, S500, S600 | 325 (80°) |
| S300 TDI | Data not provided |
| Speed/TDC sensor resistance, Ohm | |
| S280, S320 | 680-1200 |
| Injector resistance, Ohm | 14-16 |
| Injector opening time, ms, at rpm | |
| S280, S320 | 2.5-3.8, at 700 |
Adjustment data
Checking the setting of the injection start moment of the high-pressure fuel pump
Crankshaft position marks when adjusting the injection pump 24° (EGR 19°) before TDC
Adjusting the idle speed (tDI models)
| Idle speed (are supported automatically) | |
| S280, S320 | 650-800 |
| S420, S500, S600 | 675±50 |
| S300 TDI | 560-660 |
| No-Load Speed Limit | |
| S300 TDI | 4600-4900 |
| CO content at idle speed, with oil heated to 60°C | Not more than 0.5% |
| HC content at idle revolutions, ppm (particles) | 100 |
| CO₂ content at idle speed | 14.5-16% |
| O2 content at idle speed | 0.1-0.5% |
| CO content at 2200-2800 rpm | 0.3% |
| Lambda value at 2200-2800 rpm | 0.97-1.03 |
| Adjustment position of the fuel injection pump (see illustration) | 24° before TDC |
Tightening force of threaded connections, Nm
Tightening torques for fasteners are also given in the text of the Chapter and in some illustrations*.
* Tightening torques highlighted in bold in the text must be strictly observed; efforts not shown in bold are only approximate.
| Oxygen sensor | 50-60 |
| Knock sensor | 20 |
| CKP sensor mounting bolt | 10 |
| CMP sensor mounting bolt | 10 |
| Fuel line nipple connectors | 10-14 |