You'll find everything you need right here:

http://www.startekinfo.com/StarTek/outside/9511/?requestedDocId=9511

The recommended engine oils are on page 4 (page 3 if you go by the numbers on the actual document.) Even if you did have an owner's manual, you'd still have to reference the above site because it doesn't list any specific oil in the manual. The manual for my 140 simply says, "Please consult your local Mercedes-Benz dealer for recommended engine oils." I don't know why the manuals for the newer models don't list the specific oil for the vehicles.