WARNING
If engine oil comes into contact with hot engine parts, it may ignite and you could burn yourself. Do not spill any engine oil on hot engine parts.

Environmental note
When adding oil, take care not to spill any. If oil enters the soil or waterways, it is harmful to the environment.

Use only engine oils and oil filters that have been approved for vehicles equipped with a service system. A list of the engine oils and oil filters tested and approved in accordance with the Mercedes-Benz Specifications for Service Products can be called up by visiting http://www.mbusa.com (USA only). More information about tested and approved engine oils and oil filters is available from any authorized Mercedes-Benz Center.
Damage to the engine or exhaust system is caused by the following:
• using engine oils and oil filters which have not been specifically approved for the service system.
• replacing the engine oil or oil filter after the replacement interval required by the service system has elapsed
• using engine oil additives.

Do not add too much oil. If the oil level is above the "max" mark on the dipstick, too much oil has been added. This can lead to damage to the engine or the catalytic converter. Have excess oil siphoned off.

Example: engine oil cap

Turn cap 1 counterclockwise and remove it.
Add engine oil.
If the oil level is at or below the MIN mark on the oil dipstick, add 0.55 to 1.1 US qt (0.5 to 1.0 l) engine oil.
Replace cap 1 on the filler neck and turn clockwise.
Ensure that the cap locks into place securely.
Check the oil level again with the oil dipstick.

Further information on engine oil.